Browsing by Subject "cancer therapy"

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    EFFECTS OF RESVERATROL ON PACLITAXEL-SENSITIVE AND –RESISTANT TRIPLE NEGATIVE BREAST CANCER CELLS
    (Office of the Vice Chancellor for Research, 2012-04-13) Sprouse, Alyssa A.; Herbert, Brittney-Shea
    Treatment of drug-resistant cancer cells remains a difficult problem in cancer therapy because most resistant cells can pump out drugs or upregulate other survival pathways to bypass a targeted therapy. The poly-phenol natural compound, resveratrol, has been shown to inhibit cell growth of multiple cancer types, but it is not cytotoxic to normal cells. However, the effects of resveratrol in triple negative breast cancer cells as well as cancers that are resistant to the common cancer drug, paclitaxel, are not well under-stood. In this study, the effects of resveratrol were investigated in the triple negative breast cancer cell line MDA-MB-231 as well as a novel paclitaxel-resistant MDA-MB-231 derived line generated in our laboratory. Both cell lines exhibited a reduction in cell proliferation after resveratrol treatment, with the paclitaxel-resistant cells to a greater extent. In addition, resveratrol decreased the ability of both cell lines to form colonies when plated at low density indicating reduced cell survival capacity. Resveratrol treatment also increased the amount of DNA fragmentation associated with cell death in both cell lines, again with the paclitaxel resistant cells being more sensitive. By protein expression analyses, we observed that in both the parental and resistant cell lines, resveratrol may be acting by through NAD-dependent deacetylase sirtuin (SIRT1) activity by decreasing the expression of the in-hibitor-of-apoptosis protein, survivin, as well as increasing the activator-of-cell death, caspase 7. These data suggest that resveratrol can inhibit prolif-eration and induce cell death in triple negative breast cancer cells, including paclitaxel-resistant cells. In addition, these results provide rationale for the use of resveratrol as an important starting point for the development of a novel anti-cancer agent for drug resistant, aggressive cancers as well as in combination with other anti-cancer drugs without significant toxicity to nor-mal cells.
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    Implications of Incidental Germline Findings Identified In the Context of Clinical Whole Exome Sequencing for Guiding Cancer Therapy
    (ASCO, 2020) Schneider, Bryan P.; Stout, Leigh Anne; Philips, Santosh; Schroeder, Courtney; Scott, Susanna F.; Hunter, Cynthia; Kassem, Nawal; Kiel, Patrick J.; Radovich, Milan; Medicine, School of Medicine
    PURPOSE Identification of incidental germline mutations in the context of next-generation sequencing is an unintended consequence of advancing technologies. These data are critical for family members to understand disease risks and take action. PATIENTS AND METHODS A retrospective cohort analysis was conducted of 1,028 adult patients with metastatic cancer who were sequenced with tumor and germline whole exome sequencing (WES). Germline variant call files were mined for pathogenic/likely pathogenic (P/LP) variants using the ClinVar database and narrowed to high-quality submitters. RESULTS Median age was 59 years, with 16% of patients ≤ 45 years old. The most common tumor types were breast cancer (12.5%), colorectal cancer (11.5%), sarcoma (9.3%), prostate cancer (8.4%), and lung cancer (6.6%). We identified 3,427 P/LP variants in 471 genes, and 84% of patients harbored one or more variant. One hundred thirty-two patients (12.8%) carried a P/LP variant in a cancer predisposition gene, with BRCA2 being the most common (1.6%). Patients with breast cancer were most likely to carry a P/LP variant (19.2%). One hundred ten patients (10.7%) carried a P/LP variant in a gene that would be recommended by the American College of Medical Genetics and Genomics to be reported as a result of clinical actionability, with the most common being ATP7B (2.7%), BRCA2 (1.6%), MUTYH (1.4%), and BRCA1 (1%). Of patients who carried a P/LP variant in a cancer predisposition gene, only 53% would have been offered correct testing based on current clinical practice guidelines. Of 471 mutated genes, 231 genes had a P/LP variant identified in one patient, demonstrating significant genetic heterogeneity. CONCLUSION The majority of patients undergoing clinical cancer WES harbor a pathogenic germline variation. Identification of clinically actionable germline findings will create additional burden on oncology clinics as broader WES becomes common.
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    Molecular Mechanisms of Paclitaxel Resistance and Resveratrol Sensitivity in MDA-MB-231 Breast Cancer Cells
    (Office of the Vice Chancellor for Research, 2013-04-05) Sprouse, Alyssa A.; Herbert, Brittney-Shea
    Treatment of drug-resistant cancer cells remains a difficult problem in cancer therapy because most resistant cells can pump out drugs or upregulate other survival pathways to bypass a targeted therapy. To study cancers that are resistant to the common cancer drug, paclitaxel, a novel paclitaxel-resistant cell line was generated from the breast cancer cell line MDA-MB-231. A “spiking” method of paclitaxel treatment was used to select for a population of cells that are resistant to the drug. This method mimics the development of resistance in recurrent tumors in patients. However, it is difficult to study such a heterogeneous population. To better study these cells, the paclitaxel-resistant cell line was cloned using a limiting dilution method to provide more homogeneous populations of resistant cells. The 29 clones obtained exhibited a paclitaxel IC50 range of 8 μM to 78 μM which was equivalent to a 200- to 2000-fold increase in resistance compared to the parent line. It has been suggested that the polyphenol natural compound, resveratrol, which has been shown to inhibit cell growth of multiple cancer types, may be useful as a combination anti-cancer treatment or novel therapeutic for drug-resistant cancer cells. The parent line, the heterogeneous resistant line, the least paclitaxel-resistant clone and the most paclitaxelresistant clone were similarly sensitive to resveratrol treatment. We observed that treatment with 10-100 μM concentrations of resveratrol in all cell lines showed a reduction in cell proliferation and increased apoptosis within 72 hours (p<0.05), with the paclitaxel-resistant cells to a greater extent. In addition, resveratrol decreased the ability of the parent, heterogeneous resistant and the highest resistant clone cells to form colonies (an indication of reduced cell survival capacity). This resistant cell line and its clones provide a powerful tool to study paclitaxel-resistance in and therapeutics for breast cancer.
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    Novel Insights into the Roles of Rho Kinase in Cancer
    (Springer, 2016-08) Wei, Lei; Surma, Michelle; Shi, Stephanie; Lambert-Cheatham, Nathan; Shi, Jianjian; Department of Pediatrics, IU School of Medicine
    Rho-associated coiled-coil kinase (ROCK) is a major downstream effector of the small GTPase RhoA. The ROCK family, consisting of ROCK1 and ROCK2, plays a central role in the organization of the actin cytoskeleton, and is involved in a wide range of fundamental cellular functions such as contraction, adhesion, migration, proliferation, and apoptosis. Since the discovery of effective inhibitors such as fasudil and Y27632, the biological roles of ROCK have been extensively explored in numerous diseases, including cancer. Accumulating evidence supports the concept that ROCK plays important roles in tumor development and progression through regulating many key cellular functions associated with malignancy, including tumorigenicity, tumor growth, metastasis, angiogenesis, tumor cell apoptosis/survival and chemoresistance as well. This review focuses on the new advances of the most recent 5 years from the studies on the roles of ROCK in cancer development and progression; the discussion is mainly focused on the potential value of ROCK inhibitors in cancer therapy.
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    Promising molecular mechanisms responsible for gemcitabine resistance in cancer
    (Elsevier, 2015-12) Jia, Yanfei; Xie, Jingwu; Department of Pediatrics, IU School of Medicine
    Gemcitabine is the first-line treatment for pancreatic ductual adenocarcinoma (PDAC) as well as acts against a wide range of other solid tumors. Patients usually have a good initial response to gemcitabine-based chemotherapy but would eventually develop resistance. To improve survival and prognosis of cancer patients, better understanding of the mechanisms responsible for gemcitabine resistance and discovery of new therapeutic strategies are in great need. Amounting evidence indicate that the developmental pathways, such as Hedgehog (Hh), Wnt and Notch, become reactivated in gemcitabine-resistant cancer cells. Thus, the strategies for targeting these pathways may sensitize cancer cells to gemcitabine treatment. In this review, we will summarize recent development in this area of research and discuss strategies to overcome gemcitabine resistance. Given the cross-talk between these three developmental signaling pathways, designing clinical trials using a cocktail of inhibitory agents targeting all these pathways may be more effective. Ultimately, our hope is that targeting these developmental pathways may be an effective way to improve the gemcitabine treatment outcome in cancer patients.
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    Recurrent Metastatic High‑Grade Osteosarcoma: Disease Stabilization and Successful Pregnancy Outcome following Aggressive Multimodality Treatment
    (Wolters Kluwer, 2018) Khurana, Monica; Gruner, Barbara; Sathi, Bindu Kanathezhath; Medicine, School of Medicine
    Prognosis for refractory/recurrent metastatic osteosarcoma (OS) remains dismal with 3-year survival rates <20%. Achievement of more than 5 years of stable, refractory/recurrent metastatic OS disease in our patient is itself unique and attributable to multimodality therapy. Her high-dose chemotherapy regimen with alkylating agents did not lead to infertility, making her case even more unique. Successful disease stabilization and pregnancy outcome in our patient with metastatic multiple relapsed OS is one of the first cases published. We need further understanding and exploration of pathogenesis, chemoresistant mechanisms, and multimodality therapies including immunotherapy for OS.