35 research outputs found

    Antagonizing CD105 enhances radiation sensitivity in prostate cancer.

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    Radiation therapy is the primary intervention for nearly half of the patients with localized advanced prostate cancer and standard of care for recurrent disease following surgery. The development of radiation-resistant disease is an obstacle for nearly 30-50% of patients undergoing radiotherapy. A better understanding of mechanisms that lead to radiation resistance could aid in the development of sensitizing agents to improve outcome. Here we identified a radiation-resistance pathway mediated by CD105, downstream of BMP and TGF-β signaling. Antagonizing CD105-dependent BMP signaling with a partially humanized monoclonal antibody, TRC105, resulted in a significant reduction in clonogenicity when combined with irradiation. In trying to better understand the mechanism for the radio-sensitization, we found that radiation-induced CD105/BMP signaling was sufficient and necessary for the upregulation of sirtuin 1 (SIRT1) in contributing to p53 stabilization and PGC-1α activation. Combining TRC105 with irradiation delayed DNA damage repair compared to irradiation alone. However, in the absence of p53 function, combining TRC105 and radiation resulted in no reduction in clonogenicity compared to radiation alone, despite similar reduction of DNA damage repair observed in p53-intact cells. This suggested DNA damage repair was not the sole determinant of CD105 radio-resistance. As cancer cells undergo an energy deficit following irradiation, due to the demands of DNA and organelle repair, we examined SIRT1's role on p53 and PGC-1α with respect to glycolysis and mitochondrial biogenesis, respectively. Consequently, blocking the CD105-SIRT1 axis was found to deplete the ATP stores of irradiated cells and cause G2 cell cycle arrest. Xenograft models supported these findings that combining TRC105 with irradiation significantly reduces tumor size over irradiation alone (p value = 10-9). We identified a novel synthetic lethality strategy of combining radiation and CD105 targeting to address the DNA repair and metabolic addiction induced by irradiation in p53-functional prostate cancers

    Survival Impact of Adjuvant Therapy in Salivary Gland Cancers following Resection and Neck Dissection

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    Objective To evaluate the impact of postoperative radiotherapy (PORT) and chemotherapy on survival in salivary gland cancer (SGC) treated with curative-intent local resection and neck dissection. Study Design Retrospective population-based cohort study. Setting National Cancer Database. Subjects and Methods Patients with SGC who were undergoing surgery were identified from the National Cancer Database between 2004 and 2013. Neck dissection removing a minimum of 10 lymph nodes was required. Because PORT violated the proportional hazards assumption, this variable was treated as a time-dependent covariate. Results Overall, 4145 cases met inclusion criteria (median follow-up, 54 months). PORT was associated with improved overall survival in multivariable analysis, both 9 months (HR, 0.75; 95% CI, 0.66-0.86; P <.001). In propensity score-matched cohorts, 5-year overall survival was 67.1% and 60.6% with PORT and observation, respectively (P <.001). Similar results were observed in landmark analysis of patients surviving at least 6 months following diagnosis. Adjuvant chemotherapy was not associated with improved survival (HR, 1.15; 95% CI, 0.99-1.34; P = .06). Conclusion PORT, but not chemotherapy, is associated with improved survival among patients with SGC for whom neck dissection was deemed necessary. These results are not applicable to low-risk SGCs not requiring neck dissection.Peer reviewe

    Unification of favourable intermediate‐, unfavourable intermediate‐, and very high‐risk stratification criteria for prostate cancer

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139069/1/bju13903.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139069/2/bju13903_am.pd

    Taselisib (GDC-0032), a Potent  -Sparing Small Molecule Inhibitor of PI3K, Radiosensitizes Head and Neck Squamous Carcinomas Containing Activating PIK3CA Alterations

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    Activating PIK3CA genomic alterations are frequent in head and neck squamous cell carcinoma (HNSCC), and there is an association between phosphoinositide 3-kinase (PI3K) signaling and radioresistance. Hence, we investigated the therapeutic efficacy of inhibiting PI3K with GDC-0032, a PI3K inhibitor with potent activity against p110α, in combination with radiation in HNSCC
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