Cancer

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12503/31251

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TESTICULAR TORSION IN A NEONATE
(2013-04-12) Gowani, Faaria
Purpose: This poster will present a rare case of a congenital testicular teratoma in a 4 week old male who presented to Cook Children's Emergency Department with a testicular torsion. We will discuss the imaging studies of choice and management when investigating scrotal masses and testicular swelling. Methods: Retrospective review of one patient's medical records, including imaging studies and pathology results, from date of admission to discharge as well as a review of pertinent literature. A transcrotal surgical approach was used rather than an inguinal approach because the primary concern was torsion at the time. During the operation, the surgeon noted the testicle to be grossly torsed, uniformly gray and hardened. The appearance was consistent with a tumor and so the testicle was resected and sent for pathology. Results: In respect to diagnosis of testicular masses, literature favors radiologic imaging like CT scan. When testicular torsion is suspected, however, the imaging studies of choice are ultrasound with Doppler. Conclusions: The appropriate use of imaging modalities is pivotal when approaching testicular changes in the perinatal period. When Doppler ultrasound suggests ischemic damage is eminent, it is imperative to prioritize saving a testicle over obtaining an exact diagnosis of the cause. Neonatal teratomas are rare, for the most part clinically benign and usually diagnosed at birth. In this case, however, the teratoma presented as a testicular torsion which required emergent surgery before a sure diagnosis of the cause could be made. Further studies need to be done to determine the best approach to testicular torsions in the neonatal period.
TETRANDRINE: A NOVEL CHEMOPREVENTIVE AGENT
(2013-04-12) Gibbs, Lee
Purpose: The development and study of chemopreventive agents may be promising in combating aggressive behavior of triple-negative breast cancer. Tetrandrine, a bis-benzylisoquinoline alkaloid isolated from the root of Stephania tetrandra, is a calcium channel blocker used in Chinese medicine for the treatment of silicosis and arthritis. Studies have shown that tetrandrine also has anti-tumor and anti-growth activities. Our objective is to study the effects of tetrandrine on the localization of Annexin A2 (36 kDa calcium-dependent phospholipid binding protein) and determine the implication of this in the overall cell proliferation and cancer metastasis processes. We hypothesize that inhibition of calcium trafficking by tetrandrine will inhibit the migration, invasion and proliferation via attenuation of AnxA2 localization to the plasma membrane Methods: We have used Her-2 positive, triple-negative, and non-cancerous breast cell lines (MDA-MB-231, HCC70, BT474, SKBR3, and MCF-10A) to study the effects of tetrandrine. MTT assays were carried out to determine the effect of tetrandrine on cell viability. Additionally, cells were subjected to the Versene wash to analyze the effect of calcium depletion on the AnnXA2 localization in cells. Effects of tetrandrine on the expression and localization of Annexin A2 were also analyzed by the immunofluorescence and the Western blot analyses of the sub cellular fractions of the control and treated cells. Results: The viability of the cells at various concentrations of tetrandrine after incubation of 48 h measured by MTT assay showed IC50 values of 20uM, 25uM, 30uM, 40uM, and 75uM for HCC70, MDA MB231, SKBR3, BT474, and MCF10A respectively. Annexin A2 translocation to the membrane was analyzed by using a) versene (calcium ion chelating agent) washed cells, b) Western blot analyses of membrane and cytosolic extracts and c) Immunofluorescence of control and tetrandrine treated cells. Results of these studies indicated that treatment of breast cancer cells with tetrandrine did not show any significant effect on the Annx.A2 accumulation in plasma membrane of these cells when compared with the control cells. Conclusions: Our results suggest that tetrandrine inhibits the proliferation of breast cancer cells through mechanisms independent of Annexin A2. Significantly high IC50 value for MCF10A compared to the breast cancer cells indicates that this phyto-chemical may be used as a cancer chemopreventive agent.
FORMULATION AND CHARACTERIZATION OF TOLFENAMIC ACID ENCAPSULATED PLGA NANOPARTICLES FOR CANCER THERAPY
(2013-04-12) Bhaidani, Beenish
Purpose: Tolfenamic acid, an NSAID, is derived from the willow tree. It is water insoluble and has low bioavailability in humans. Nanotechnology can help increase the bioavailability of water insoluble compounds. This research project will demonstrate the cellular uptake and bioavailability of poly(lactic-co-glycolic acid) nanoparticles with tolfenamic acid. In the future, results from this study can be applied to other water insoluble, plant derived compounds for cancer therapy. Hypotheses: 1) Tolfenamic (TFA) PLGA nanoparticles (np) will have a higher bioavailability than free tolfenamic acid and be more efficacious for cancer therapy. 2) TFA-PLGA np formulated with binary solvent will have a higher encapsulation efficiency than pure organic solvent. Methods: Methods included particle size analysis, calculating encapsulation efficiency and drug loading, cellular uptake of TFA-PLGA np, effect of TFA-PLGA np on cell lines (Panc-1, MiaPaCa, and BxPC3), and effect of TFA-PLGA np on cell migration. Results: Results: The encapsulation efficiency was found to be 65-75% with ethyl acetate. With the binary solvent formulation, encapsulation efficiency increased to 94%.Robust intracellular uptake was seen in three different pancreatic cell lines. MTT assay revealed that IC50 values for TFA-PLGA np was 120 µM as compared to 372 µM for free TFA. Scratch assay revealed that TFA-PLGA np had inhibitory effect on migration of pancreatic cancer cells. Conclusions: Conclusions: TFA PLGA np had a higher bioavailability and will be more efficacious for cancer therapy than free TFA. The migration assay also indicated that the TFA np had reduced invasive potential.
REGULATION OF CELL DEATH BY INHIBITOR OF KAPPA-B KINASE IN TRIPLE NEGATIVE BREAST CANCER CELLS
(2013-04-12) Patel, Dipali
Purpose: Triple-negative breast cancer (TNBC) is characterized by the lack of estrogen receptor, progesterone receptor, and HER2/neu and hence poses problems for targeted therapy. Thus there is an urgent need to identify suitable molecular targets for the treatment of TNBC. The inhibitor of kappa-B kinase-epsilon (IKK-epsilon) is a breast cancer specific oncogene that is elevated in TNBCs and plays an important role in breast cancer cell survival. Cancer cells often evade death by overcoming apoptosis or type I programmed cell death. However, the role of autophagy or self-digestion in cancer is ambiguous. While a low level of autophagy promotes cell survival under stress, excessive autophagy may lead to type II programmed cell death. The purpose of this project is to determine the mechanism by which IKK-epsilon promotes survival of breast cancer cells. Methods: Triple-negative breast cancer MDA-MB-231 cells were transfected with non-targeting control siRNA or siRNA against appropriate genes. Proteins were separated using SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis). Western blot analysis and enhanced chemiluminescence were used to study the overall levels of apoptosis and autophagy markers. Results: Knockdown of IKK-epsilon in MDA-MB-231 potentiated tumor necrosis factor-alpha (TNF)-induced apoptosis. IKK-epsilon knockdown also showed a decrease in p62/SQSTM1 and an increase in proteins associated with autophagy induction. Conclusions: The increase in autophagic markers in IKK-epsilon depleted cells suggests that IKK-epsilon protects MDA-MB-231 cells by promoting autophagy. Understanding the specific mechanism of survival of TNBC cells could aid in developing effective therapy.
FORMULATION AND CHARACTERIZATION OF POLYMERIC NANOPARTICLES FOR CANCER TREATMENT CONCEPTUAL APPROACH
(2013-04-12) Castañeda-Gill, Jessica M.
Purpose: Cancer treatments currently used in the clinic have demonstrated their effectiveness over the last 50 years, however, little has been done to improve their resultant toxic side effects. Most chemotherapy and radiation treatments produce varying outcomes in patients, from hair loss to nausea to infection and metastasis; this begs the question as to why there has been minimal research aimed at developing less harmful therapies. With the advent of nanotechnology during the last few decades, the drug development process has switched to biodegradable nanoparticle (NP) drug delivery systems as a means to improve drug efficacy, while reducing toxic side effects. In this project, formulation and characterization of biodegradable polylactide-co-glycolide (PLGA) NPs is discussed and performed, in order to provide cancer therapy options that could be more effective and less harmful. Methods: PLGA NPs have been used to encapsulate hydrophobic drugs, small molecules, DNA/RNA, etc. effectively, with high drug loading, depending on the formulation. In this project, PLGA NPs were used to encapsulate cancer therapy drugs using sonication and established water-in-oil-in water (W/O/W) procedures. Following formulation, the PLGA NPs were characterized via a Nanotrac particle size analyzer. The aforementioned PLGA NPs can now be used in in vitro and in vivo studies to determine their effectiveness as cancer treatments. Results: Several PLGA NP formulations were produced, with different loading components and sizes. Implementation of sonication and W/O/W emulsion techniques were important factors that affected NP size and drug loading. Regardless, from batch to batch, for each formulation, NP size was consistent (140-190nm). The small size of the PLGA NPs (<200nm) demonstrates the increased likelihood of uptake by cancer cells, either in vitro or in vivo, which is important for effective treatment. Conclusions: With the dawn of nanomedicine, particularly cancer therapy, the development of better, less harmful drugs is more likely. Through the use of PLGA NPs, an FDA-approved, biodegradable drug delivery system, cancer treatments could be more effective, due to the potential for targeting of cancer cells and reduced toxic side effects, ultimately increasing a patient's quality of life. Due to their small size, flexibility of content loading, surface functionalization, biodegradability/biocompatibility, and enhanced uptake by cancer cells, PLGA NPs could improve treatments and patient prognosis.
CASE PRESENTATION AND LITERATURE REVIEW OF SQUAMOUS HISTOLOGY IN UTERINE CANCER
(2013-04-12) Jaynes, Jennifer
Purpose: Although the most common form of endometrial cancer is pure endometrioid adenocarcinoma, there have been many instances of endometrioid adenocarcinoma with squamous differentiation. However, the incidence of pure squamous carcinoma of the endometrium is very rare. Here a case is presented of a woman with endometrial cancer that was found to contain both glandular and squamous components and was described as endometrial adenocarcinoma with extensive squamous morule formation with areas of necrosis. The objective is to compare and contrast endometrioid adenocarcinoma with squamous differentiation (EASD) and primary squamous carcinoma of the endometrium (PSCE). Methods: A current literature review of online research databases and relevant scientific journals was performed in order to compare what is known about the incidence, etiology, histopathology, diagnosis, treatment, and prognosis of PSCE with that of EASD. Results: The origin of the squamous differentiation within endometrioid adenocarcinoma arises from squamous metaplasia of glandular tissue that eventually forms adenocarcinoma. However, the origin of PSCE is postulated to arise from stem cells between glandular basement membrane and endometrial columnar epithelium. While one possible component of treatment for EASD is hormone therapy, PSCE has been shown not to express estrogen or progesterone receptors and thus is not responsive to hormone therapy. The prognosis for pure endometrioid adenocarcinoma at five years for stage I disease is 89.1%; for stage II disease is 78.8%; for stage III disease is 57.8%; and for stage IV disease is 22%. EASD has been shown to have a worse prognosis than pure endometrioid adenocarcinoma. PSCE is much less common and thus only studied out to one year. At one year, the prognosis for stage I disease is 80%; for stage III is 20%; and for stage IV is 0%. Conclusions: While EASD and PSCE share the similarity of squamous features, PSCE carries a much worse prognosis with more limited treatment options. With so few cases and so little known about PSCE, further research on this lethal carcinoma is warranted
ALTERED EXPRESSION OF IMMUNE RECEPTORS 2B4, CS1 AND LLT1 IN CHILDREN WITH ACUTE LYMPHOBLASTIC LEUKEMIA (ALL)
(2013-04-12) Tan, Charisse
Purpose: Acute lymphoblastic leukemia is the most common type of leukemia found in children with peak prevalence between the ages of 2 and 5. In ALL, there is uncontrolled, exaggerated growth and accumulation of lymphoid progenitor cells, which fail to properly differentiate and function as normal lymphocytes. Despite current treatment protocols that have been successful in the vast majority of ALL patients, serious acute and late complications are frequent and resistance to chemotherapy often develops. Natural Killer (NK) cells, which are components of the lymphocyte population, can recognize and act on target cells under the control of their cell surface receptors. Binding of these receptors to specific ligands on the target cell results in signaling which either activates or inhibits NK cell effector functions. We have previously identified cell surface receptors 2B4, CS1 and LLT1 playing a major role in NK cell activation. Previous studies on these receptors implicate that these receptors may play a role in cancers, however their significance and role in childhood ALL have not been evaluated. We hypothesize that altered expression of these immune receptors play a role in acute lymphoblastic leukemia in children. Methods: ALL subjects and healthy subjects were enrolled at Cook Children's Hospital and UNT Health Science Center, Fort Worth, TX with informed consent/assent according to IRB approval. Peripheral blood mononuclear cells (PBMC) were isolated from whole blood of twelve ALL subjects and three healthy subjects. NK92-MI cell line was used as a positive control. Total RNA was extracted and reverse transcribed (RT-PCR) into complimentary DNA (cDNA). PCR was performed using primers specific to 2B4, CS1, LLT1, and expression was normalized to β-actin. Results: ALL subjects showed altered expression of 2B4 in PBMC as compared to healthy subjects. There was an overall decrease in the expression of CS1 receptor in ALL subjects as compared to healthy subjects. Interestingly, both ALL and healthy subjects showed expression of different isoforms of the LLT1 receptor with variations in their expression level. Conclusions: Results implicate that there are alterations in the expression of immune receptors that may mediate the immune dysregulation in ALL subjects. Expression and functional analysis of these receptors in a larger population of ALL subjects will provide vital knowledge furthering our understanding of the etiology of ALL, progression, and developing potential immunotherapies.
SR-B1 RHDL DIRECTED NANOPARTICLES AS A DRUG DELIVERY SYSTEM AGAINST TRIPLE NEGATIVE BREAST CANCER
(2013-04-12) Johnson, Rebecca
Purpose: Triple Negative Breast Cancer (TNBC), is a heterogeneous group of tumors with diverse histology, molecular uniqueness and response to treatment. As a result of ineffective treatments, TNBC tumors often progress to metastatic lesions in the brain and lung. Brain metastases of invasive breast cancer are associated with 1 and 2 year survival rate of 20% and < 2% respectively. Current anti-HER2 or hormone positive targeted breast cancer treatments do not benefit TNBC patients; consequently, these patients rely primarily on chemotherapy. Alternative targeted therapies are urgently needed to improve survival for TNBC patients. This study is focused on developing a new approach for filling the current void in effective treatment for TNBC patients. Methods: Cells were seeded and treated with free drug and drug loaded rHDl particle for 24 hours. Cell Viability was determined using the cell viability assay CCK8. 96 well plates were read at 450nm Results: Using the CCK8 cell viability assay preliminary data reveals the potential of Temsirolimus loaded rHDL nanoparticles to reduce the effective concentration at lower doses vs. the free drug in the MDA-MB-231 cell line. Conclusions: rHDL particles are small non-immunogenic nanoparticles that have the potential to decrease the side effects that accompany high concentrations of chemotherapeutic drugs. This study proposes the using the mTOR inhibitor Temsirolimus encapsulated into the rHDL nanoparticle as an effective treatment against TNBC vs the free drug.
PREPARATION AND CHARACTERIZATION OF NOVEL MULTIFUNCTIONAL LIPOPOLYMERIC HYBRID NANOSYSTEMS FOR IMAGING AND THERAPY OF HIGHLY METASTATIC BREAST CANCER
(2013-04-12) Mukerjee, Anindita
Purpose: The technology based design of nanosystems has become more complex over the years since it now combines multiple functionalities within nanoparticles as a single delivery system. One such design involves combining the advantages of biodegradable polymeric nanoparticles with the biomimetic properties of liposomes. In this study, we have successfully engineered a multifunctional lipopolymeric hybrid nanosystem encapsulating an anticancer agent, curcumin, with a fluorescently labeled dye for imaging and therapy of breast cancer. Methods: Functionalized curcumin loaded hybrid nanoparticles for was prepared by nanoprecipitation method. The hybrid nanoparticles thus formulated were then characterized for drug loading, particle size, zeta potential and surface morphology. To evaluate our nanosystems, intracellular uptake of these drug loaded nanosystems along with its effect on cellular migration in non-malignant (MCF10A) and highly malignant metastatic breast cancer cell lines (MCF10CA1a) was determined. Further, functional assays like cell viability assay were carried out to determine the functional integrity of the encapsulated drug. Long-term stability analysis of the hybrid nanoparticles were carried out for 6 days at room temperature. Results: The formulation of the lipopolymeric hybrid nanosystem by nanoprecipitation was found to be successful with a drug loading of 12.4 ± 0.8 µg/mg of nanoparticles for curcumin. The particle size distribution was narrow with the mean particle size being 116.8 ±10 nm. The zeta potential of these hybrid nanoparticles was determined to be -31.66mV.The surface morphology of the hybrid nanoparticles was determined by Transmission Electron Microscopy. Results revealed smooth and spherical nanoparticles. Intracellular uptake studies were carried out in highly malignant breast cancer cell line, MCF10CA1a. Confocal Microscopy scans show robust cellular uptake of the fluorescently labeled hybrid nanosystems. Long-term stability analysis results reveal that these hybrid nanoparticles are stable in PBS for as long as 6 days with only ±5 nm change observed in mean particle size. Conclusions: We successfully formulated the lipopolymeric hybrid nanosystem with a fluorescently labeled dye and an anticancer agent. This type of a combinatorial theranostic system platform would allow for imaging and therapy with much less side effects than the traditional treatments because it will use anticancer agents at lower doses than used in current chemotherapies.
ITAM PHOSPHORYLATION OF THE ADAPTER PROTEIN MIEN1 CONTRIBUTES TO ITS MIGRATION AND INVASION POTENTIAL
(2013-04-12) Kpetemey, Marilyne
Purpose: Metastasis is one of the major causes of treatment failure in cancer patients. This process involves cell migration, stromal invasion, intravasation into the circulatory system leading to cancer proliferation. Identifying metastasis promoting and suppressing genes and their mechanisms of action will provide new insights into the pathogenesis and management of cancer. Previously known as C17orf37 or C35, Migration and Invasion enhancer 1 (MIEN1) is a novel gene that is over-expressed in a wide range of tumors. MIEN1 has been reported to be a critical regulator of cell migration and invasion. MIEN1 has a prenylation motif and an immunoreceptor tyrosine-based activation motif (ITAM), commonly found in signaling chains and receptors. The presence of a prenylation and ITAM domains in MIEN1 suggests that prenylation and/or tyrosine phosphorylation of the ITAM motif are important for its functions. The objective of the present study is to elucidate the molecular mechanisms through which MIEN1 promotes migration in breast cancer and whether or not tyrosine phosphorylation is important. Methods: We knockdown the expression of MIEN1 in MDA-MB231 and MCF10CA1 by siRNA and compared the migration of these cells with their respective controls. To study the importance of tyrosine phosphorylation of MIEN1- ITAM in migration and invasion, NIH3T3 were stably transfected with wild type MIEN1 or its phospho-mutants and used for migration and invasion assays. Results: Silencing of MIEN1 expression in MDA-MB231 and MCF10CA1 led to a significant decrease in breast cancer cell migration, conforming to our previous results in prostate cancer cells. Analyses of in-vitro migration and invasion assays revealed that NIH3T3 cells over-expressing MIEN1 phospho mutants failed to induce significant migration and invasion when compared with NIH3T3 over-expressing MIEN1 wild type. Conclusions: Our results show that MIEN1 plays an important role in the migration and invasion of breast cancer cells and tyrosine phosphorylation of MIEN1-ITAM significantly contributes to its functions
BELOW IS THE FORWARDED LETTER FROM THE PHYSICIAN CONCERNING THE RESEARCH PROJECT #2013-056 TITLED, GRANULAR CELL TUMOR ON VENTRAL TONGUE OF NEWBORN: A CASE REPORT.
(2013-04-12) Allphin, Christopher
Purpose: Granular cell tumors are rare neoplasms usually found in the skin or on the tongue. These tumors are most commonly found in middle-aged individuals, and they originate from the neural Schwann cells. Granular cell tumors are usually benign but are potentially malignant, which is a reason for their removal. We report a case where this rare tumor arose in an infant at birth. This is an extremely rare case because of the age group and the rare nature of these tumors. Methods: A healthy newborn, born at full term showed a mass on the midline of the ventral tongue. Infant showed no signs of airway problems, eating problems, or lack of normal development other than the mass. The mass was only visible when the baby cried. Ear, nose, and throat surgeon received consult on newborn's first day of life in nursery and determined no need for emergent resection. Results: When infant was approximately one month of age, surgeon performed conservative excision of neoplasm. He used small margins in order to ensure normal, future breathing, speaking, and tongue movement. The infant's recovery was quick and uneventful. Parents report no complications in normal growth and development. Conclusions: Conservative surgical excision is considered the best option with granular cell tumors of the tongue. When found on infants, it is important to prevent any feeding or breathing problems. Immediate removal is not necessary, and the surgery can be done as an outpatient procedure. Removal will prevent any further sequelae.
INHIBITION OF TRIPLE NEGATIVE AND HER-2 RESISTANT BREAST CANCER PROGRESSION BY ANNEXIN A2 ANTIBODIES
(2013-04-12) Chaudhary, Pankaj
Purpose: Herceptin, an immunotherapy directed against the Her-2 receptor, inhibits cancer growth and progression in Her-2 positive breast cancer by blocking the downstream survival pathways. In these cells however, the expression of another major tyrosine kinase receptor EGFR is significantly low. Interestingly, EGFR expression is significantly increased in Her-2 negative breast cancer thereby contributing to cancer growth and progression. Present studies were designed to investigate whether or not Annexin A2 (AnxA2), a calcium dependent phospholipid binding protein, regulated EGFR downstream signaling pathway and if the functions of EGFR can be inhibited by the AnxA2 antibody in TNBC and Herceptin resistant cancer cell lines. Methods: Triple negative breast cancer cell line MDA-MB-231 and Her-2 resistant breast cancer cell line JIMT-1 were grown in complete DMEM and DMEM/F12 medium respectively, in a humidified incubator at 37C with 5% CO2. The AnxA2 function at cell surface was blocked incubating with AnxA2 antibody (2µg/ml) after 12 h of serum starvation. The cells were treated with/without EGF (50ng/ml) for 20 min after 2 h of antibody treatment. The cell lysate was analyzed for pEGFR and EGFR mediated downstream signaling by Western blotting. Results: The results of the present study indicate that AnxA2 interacts with EGFR at the cell surface and plays an important role in the regulation of EGFR mediated downstream signaling. Treatment of MDA-MB-231 and JIMT-1 cells with AnxA2 antibody causes significant decrease in EGF-mediated phosphorylation of EGFR at Y845 and Y1068 sites. In addition, treatment of cells with AnxA2 antibody decreases the ligand induced EGFR dimerization and internalization. Our results also demonstrate that blocking cell surface AnxA2 functions causes the downregulation of proteins such as pAKT, and pERK1/2 which are regulated by EGFR resulting in lower cell survival, proliferation, and migration. Conclusions: These studies indicate that association of AnxA2 with EGFR in the membrane domain might play a positive regulatory role in keeping EGFR signaling events in an activated state in triple negative and Her-2 resistant breast cancer thus making AnxA2 an important therapeutic target.
EXTRACELLULAR PROLIFERATING CELL NUCLEAR ANTIGEN IS A NOVEL MARKER FOR CANCER STEM CELLS AND FACILITATES EVASION OF NK CELL EFFECTOR FUNCTION
(2013-04-12) Horton, Nathan
Purpose: Natural Killer (NK) cells are a specialized population of lymphocytes of the innate immune system which provide vital first line defense against infections and cancer. NK cell function is strictly regulated by inhibitory and activating receptors binding corresponding ligands on the surface of target cells. NKp44, originally discovered as an activating NK cell receptor, was recently found to elicit inhibitory effects on NK cell effector function through recognition of cell surface Proliferation Cell Nuclear Antigen (PCNA), which is typically only found in the cell nucleus for DNA replication and repair. Other reports have pointed to potential associations between NKp44 and Human Leukocyte Antigen (HLA) I molecules. Methods: We have identified novel interactions between HLA I and PCNA on the surface of human tumor cells by confocal microscopy and immunoprecipitation. We have also confirmed the inhibitory nature of NKp44 recognition of PCNA in association with HLA I through a standard Chromium release assay. Results: We show PCNA on the cell surface in novel association with HLA I is a natural process which does not require provocation and occurs with endogenous PCNA. The association of HLA I and PCNA forms the inhibitory ligand for NKp44, resulting in inhibition of NK effector function. Furthermore, extracellular PCNA was only found on tumor cells exhibiting a cancer stem cell phenotype. Conclusions: Thus extracellular PCNA may serve as a novel marker for cancer stem cells and provide a mechanism by which these cells evade NK cell effector functions. As a rare population of cancer cells potentially responsible for relapse after treatment, metastasis, and overall tumor growth, cancer stem cells are difficult to clinically detect in circulation and are often impervious to chemotherapy and radiation treatments. Further studies will determine the efficacy of using extracellular PCNA as a cancer stem cell marker for better detection and therapeutic targeting of these rare, yet dangerous cancer cells.
EXERCISE AND CANCER: A LITERATURE REVIEW
(2013-04-12) Smith, John
Purpose: A comprehensive review of the literature regarding the effects on exercise in cancer prevention and treatment, with the goal of elucidating non-pharmacological interventions for the possible prevention and treatment of this disease. Methods: A comprehensive literature search up to January 2013 to identify articles that examine the the effects of physical exercise and its use in prevention and treatment of cancer. Key words included: exercise, cancer, prevention, physical activity, treatment, and neoplasm. Searches were preformed using databases of PubMed, Cochrane library, CINAHL, and cancer lit. Results: The majority of research conducted with regards to breast, colon, prostate, and endometrial cancers has shown a reduction of 20 to 30% depending on the type and stage of cancer. Other cancers have seen inconsistent results, warranting the need for additional research in the development of an exercise prescription. Non-pharmacological treatment using exercise as an adjuvant therapy to the current standard of care has demonstrated to be beneficial. However, inconsistencies with respects to intensity, duration and type of exercise for cancer patients have fueled the debate as to the most effective exercise prescription for this disease process. Conclusions: The many epidemiological, clinical and experimental studies published have demonstrated an inverse relationship between physical activity and frequency of various types of cancer. These studies further substantiate the benefits and ultimately the need for specific directives for an exercise prescription to aide in the treatment of cancer.
REGULATION OF PROTEIN KINASE C-ETA IN BREAST CANCER
(2013-04-12) Pal, Deepanwita
Purpose: The protein kinase C (PKC) and phosphotidylinositide-3 kinase (PI3K) signaling pathways play critical roles in the development of breast cancer and regulate cell proliferation, differentiation, cell death and tumor promotion. PKCs serve as receptors for tumor-promoting phorbol esters, which are potent activators of conventional and novel members of the PKC family, and can substitute for the physiologic activator diacylglycerol. Prolonged treatment with phorbol esters, however, induces downregulation of these PKCs. Protein kinase C-eta is a novel member of the PKC family but resists downregulation by phorbol esters. This unique regulation of PKC-eta may have implications in tumor promotion. PKCs are regulated not only by cofactors but also by phosphorylation. Phosphorylation and dephosphorylation of PKCs can regulate their activity, stability and function. The objective of this study is to understand the regulation and contribution of PKC-eta in breast cancer. Methods: Established breast cancer cell lines were used in our study. The effect of distinct kinase inhibitors on PKCη protein levels was determined by Western blot analysis. The effect of proteasome and protease inhibitors on PKC-eta levels was also assessed by Western blotting. RNAi technique was utilized to knockdown members of the PKC and PI3K pathways. MTT assay was performed to determine the effect of PKC-eta on cell growth while cell proliferation upon PKC-eta knockdown was monitored by clonogenic assay. Results: Inhibition of PKC and PI3K pathways induced downregulation of PKC-eta via two distinct mechanisms. PKC-eta depletion inhibited the growth and proliferation of breast cancer cells. Conclusions: Our results demonstrate that the distinct regulation of PKC-eta by members of the PKC and PI3K family contributes to breast cancer cell growth.
ROLE AND REGULATION OF S6 KINASE IN BREAST CANCER
(2013-04-12) Sridharan, Savitha
Purpose: The 40S ribosomal protein S6 kinase (S6K) acts downstream of the mammalian target of rapamycin (mTOR), which is an important target for cancer therapy. mTOR inhibitors are, however, of limited success, partly due to the activation of the oncogene Akt caused by persistent inhibition of p70 S6 kinase or S6K1 via a negative feedback loop. S6K exists as two homologs, S6K1 and S6K2. While both homologs are overexpressed in breast cancer, little is known about the regulation and functions of S6K2. The objective of the present study is to determine pathways promoting S6K overexpression and whether S6K homologs perform redundant or distinct functions with respect to Akt activation and breast cancer cell survival. Methods: Breast cancer cells were transfected with non-targeting siRNA or siRNA against appropriate proteins and treated with cell death stimuli such as tumor necrosis factor-alpha (TNF), TNF-related apoptosis-inducing ligand (TRAIL), doxorubicin and paclitaxel. Cell death was monitored by staining cells with Annexin V/Yo-pro and propidium iodide. The levels of various proteins were determined by Western blotting. Results: S6K levels correlated with hormone receptor status and signaling through the hormone receptor pathway increased S6K levels. Silencing of S6K1 inhibited whereas knockdown of S6K2 potentiated cell death by various apoptotic stimuli, including TNF and TRAIL. In contrast to S6K1, depletion of S6K2 decreased basal and TNF-induced Akt phosphorylation. Ectopic expression of constitutively-active Akt in MCF-7 cells restored cell survival in S6K2-depleted cells. We have previously shown that activation of Akt induces downregulation of Bid via p53. Knockdown of S6K2 caused an increase in p53 and silencing of Bid blunted the ability of S6K2 deficiency to enhance TNF-induced apoptosis. Conclusions: Our study addresses the mechanism of S6K overexpression and demonstrates for the first time that the two homologs of S6K have distinct effects on Akt activation and cell survival. Thus, targeting S6K2 rather than mTOR may be an effective therapeutic strategy to treat cancers.
CASE STUDY: A RARE PRESENTATION OF HEPATOCELLULAR CARCINOMA
(2013-04-12) Persad, Leah
Purpose: The purpose of this case study is to describe a rare presentation of metastatic hepatocellular carcinoma. This patient presented for evaluation of a large mass in the posterior neck with associated pain. This unique case will provide information to the scientific and medical community about the clinical features and diagnosis of hepatocellular carcinoma in order to increase awareness of the various manifestations of this disease. Methods: The case presentation was a retrospective chart review. The materials included progress notes from physicians, laboratory data, pathology reports, and radiology reports. Results: We discuss the clinical features and diagnosis of hepatocellular carcinoma. This patient did not present with the typical clinical features of chronic liver disease but rather with a metastatic lesion in a rare location. Obtaining a final diagnosis in this case was difficult due to the unusual metastatic spread pattern that was not easily detected by standard diagnostic procedures. Conclusions: Extrahepatic metastatic hepatocellular carcinoma should be considered in the differential diagnosis of a lytic mass affecting the cervical spine in a non-cirrhotic patient.
MICRO RNA MEDIATED REGULATION OF MIEN1 IN PROSTATE CANCER
(2013-04-12) Rajendiran, Smrithi
Purpose: MIEN1 is a membrane bound signaling molecule that triggers downstream signaling through the AKT/NF-𝛋B pathway by up-regulating key proteases and has a role in migration and invasion of cancer cells. The overall objective of this study is to identify the mechanisms that lead to the differential regulation of MIEN1 in normal and cancer cells. Though there are multiple mechanisms that are commonly studied, here, we propose to focus on the post-transcriptional regulation of MIEN1. Our data leads to the hypothesis that MIEN1 is post-transcriptionally regulated by a specific microRNA (miR) that is down-regulated in cancer, thus explaining aberrant increased expression of MIEN1 in cancer. Methods: We have performed miR in silico analysis, expression profiling, northern blotting, qPCRs, western blotting, luciferase reporter assays, migration and invasion assays, colony formation assays and stability assays to determine the effects of the miR on different aspects of MIEN1 regulation. Results: Our data indicate that MIEN1 is post-transcriptionally regulated by a specific miR which is lost in cancer cells. This miR is highly expressed in normal cells compared to a decrease in various cancer cells and this expression is inversely correlated to the expression of MIEN1. Introduction of the mimic (precursor) or inhibitor (antagomiR) led to a decrease or increase in MIEN1 expression respectively at both the RNA and protein levels. The downstream effectors were also similarly affected. The luciferase activity significantly reduced when the 3'UTR of MIEN1 was transfected with the target miR compared to the control miR, validating the direct binding of the miR. The miR decreases the migration and invasion of cells as well as the stability of MIEN1 RNA. There was a significant reduction in the colony formation capabilities and the morphology of the colonies differed in cells that were transfected with the miR along with a decrease in E-cadherin, suggesting potential involvement of the miRNA in reducing epithelial to mesenchymal transition and hence inhibiting metastasis. Conclusions: Our results demonstrate that aberrant expression of MIEN1 in cancer is attributed to a specific miR. We are currently exploring the potential of using this miR as a biomarker in prostate cancer. Since the importance of MIEN1 as a key signaling molecule in cancer is well established, understanding the mechanisms involved in its regulation will aid in designing novel and effective therapeutic strategies to treat cancer patients.
INVOLVEMENT OF ESTROGEN RECEPTOR BETA 5 IN THE PROGRESSION OF GLIOMA
(2013-04-12) Li, Wenjun
Purpose: Emerging evidence suggests a decline of ERβ expression in various peripheral cancers and ERβ has been proposed as a cancer brake that inhibits tumor cell growth and proliferation. Our current study analyzed the expression and function of ERβ in human glioma. Methods: Expression of ERβ isoforms in human glioma was analyzed using western blot, immunohistochemsitry and real-time PCR. ERβ expression regulation was investigated in GBM cell line U87. ERβ isoforms were cloned and stable cells were made to evaluate the effects of ERβ on cell signaling and growth/proliferation of GBM cells. Results: we have identified ERβ5 as the predominant isoform of ERβ in human glioma and its expression was significantly increased in human glioma as compared with non-neoplastic brain tissue. Hypoxia and activation of hypoxia inducible factor (HIF) increased ERβ transcription in U87 cells, suggesting elevated ERβ expression in glioma might be induced by the hypoxic stress in the tumor. Over-expression of either ERβ1 or ERβ5 increased PTEN expression and inhibited activation of the PI3K/AKT/mTOR pathway; ERβ5 also inhibited the MAPK/ERK pathway. In U87 cells, ERβ1 and ERβ5 decreased cell proliferation and decreased cells in the S+G2/M phase. Conclusions: Our findings suggest hypoxia induced ERβ5 expression in glioma as a self-protective mechanism against tumor proliferation and that ERβ5 might serve as a therapeutic target for the treatment of glioma.
SELECTIVE DEGRADATION OF HUMAN TIP110/SART3 IN A TRANEGNIC MOUSE MODEL: ROLE OF UBIQUITIN SPECIFIC PEPTIDASE 15
(2013-04-12) Timani, Khalid
Purpose: HIV Tat-interacting-protein 110 (Tip110) is an RNA binding protein. It is highly elevated and expressed in the nucleus of all malignant tumor cell lines tested and in the majority of cancer tissues. In addition, it regulates or interacts with several oncogenic proteins. Thus, the purpose of this study is to understand the regulatory pathways of Tip110 degradation. Methods: Transgenic human (Tg-h-Tip110) mice were created. Mouse embryonic fibroblast (MEF) cells were obtained from wild-type and Tip110 transgenic (Tg) embryos. Mass Spectroscopy, immunoprecipitation and immunofluorescence assays were performed to study the host cellular proteins interacting with Tip110. To study the physiological significant of this interaction, an in vivo deubiquitination assay was performed. Results: The Tg-h-Tip110 mice did not show any abnormalities during mouse development. Surprisingly, Tg-h-Tip110 protein was not detectable in different Tg tissues although Tg-h-Tip110 mRNA was transcribed. Treatments of Tg-MEF with proteasomal inhibiters led to detection of the Tg-h-Tip110 protein, indicating that loss of Tg-h-Tip110 in mice was due to degradation through the ubiquitin proteasomal pathway. Interestingly, h- but not m-Tip110 protein underwent selective degradation in mouse cells. This difference appeared to be consistent with the finding that h-Tip110 exhibited more ubiquitination modification in comparison to m-Tip110. Our results showed that Tip110 interacted with deubiquitionation enzyme ubiquitin specific peptidase 15 (USP15) and the expression of Tip110 resulted in the translocation of USP15 from the cytoplasm to the nucleus where they co-localized. In vivo deubiquitination assay showed that Tip110 served as a substrate for USP15 and that deubiquitination of h-Tip110 is more pronounced than m-Tip110. Unexpectedly, knock-down but not overexpression of USP15 in Tg-MEF resulted in the accumulation of Tg-h-Tip110. Conclusions: Here, we showed that h-Tip110 protein is degraded in transgenic mice through the ubiquitin proteasomal pathway. We identified the USP15 as an interacting partner with Tip110. Interestingly, the finding that the deubiquitination activity by USP15 protein was found to be more efficient for h-Tip110 in comparison to the m-Tip110 corroborated the degradation behavior of h-Tip110 in transgenic mice. These results revealed that the Tip110 protein level in tissues is under tight control, suggest that Tip110 interaction with USP15 may be responsible for its selective and rapid turnover.

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