Comparison of ACINUS, caspase-3, and TUNEL as apoptotic markers in determination of tumor growth rates of clinically localized prostate cancer using image analysis

The balance between apoptotic and proliferative processes determines the enlargement of a tumor. Accurate measurement of apoptotic and proliferative rates from diagnostic prostate biopsies would allow calculation of tumor growth rates in a population-based prostate cancer (CaP) study. Automated image analysis may be used if proliferation and apoptotic biomarkers provide clearly resolved immunostained images

Establishment of Short-Term Primary Human Prostate Xenografts for the Study of Prostate Biology and Cancer

Human tissue xenograft models are currently the only tool for conducting in vivo analyses of intact human tissue. The goal of the present study was to develop reliable methods for successful generation of short-term primary tissue xenografts from benign and tumor-derived human prostate tissue. Primary human prostate xenografts were established in athymic nu/nu mice from eight of eight benign and five of five prostate cancer tissues, collected from a total of 10 patients who underwent radical prostatectomy for the treatment of prostate cancer. An average of 13 xenografts was established per specimen. Two tissue specimens were cryopreserved for >1 month before successful generation of prostate xenografts. After 1 month in vivo, xenograft tissues were harvested and examined regarding: gross evidence of vascularization; tissue morphology; proliferation; apoptosis; and expression of androgen receptor, prostate-specific antigen, and high molecular weight cytokeratins specific for basal cells in the prostate. Direct comparison of the original tissue specimen and the 1-month xenografts revealed similar histology; similar apoptotic and proliferative fractions in most cases; and comparable expression levels and expression patterns of androgen receptor, prostate-specific antigen, and high molecular weight cytokeratins. These data demonstrate that primary human prostate xenografts, benign and malignant, can be established routinely from human prostate tissue surgical specimens, and that the xenografts maintain tissue architecture and expression of key prostatic markers. The development of this methodology, including the technique for cryopreservation of human tissue, will allow multiple (successive) analyses of human prostate tissue to be conducted throughout time using a tissue sample derived from a single patient; and simultaneous analysis of human prostate tissues derived from a cohort of patients

Neoadjuvant pazopanib and molecular analysis of tissue response in renal cell carcinoma

BACKGROUND Surgery remains the frontline therapy for patients with localized clear cell renal cell carcinoma (ccRCC); however, 20%–40% recur. Angiogenesis inhibitors have improved survival in metastatic patients and may result in responses in the neoadjuvant setting. The impact of these agents on the tumor genetic heterogeneity or the immune milieu is largely unknown. This phase II study was designed to evaluate safety, response, and effect on tumor tissue of neoadjuvant pazopanib.METHODS ccRCC patients with localized disease received pazopanib (800 mg daily; median 8 weeks), followed by nephrectomy. Five tumors were examined for mutations by whole exome sequencing from samples collected before therapy and at nephrectomy. These samples underwent RNA sequencing; 17 samples were available for posttreatment assessment.RESULTS Twenty-one patients were enrolled. The overall response rate was 8 of 21 (38%). No patients with progressive disease. At 1-year, response-free survival and overall survival was 83% and 89%, respectively. The most frequent grade 3 toxicity was hypertension (33%, 7 of 21). Sequencing revealed strong concordance between pre- and posttreatment samples within individual tumors, suggesting tumors harbor stable core profiles. However, a reduction in private mutations followed treatment, suggesting a selective process favoring enrichment of driver mutations.CONCLUSION Neoadjuvant pazopanib is safe and active in ccRCC. Future genomic analyses may enable the segregation of driver and passenger mutations. Furthermore, tumor infiltrating immune cells persist during therapy, suggesting that pazopanib can be combined with immune checkpoint inhibitors without dampening the immune response.FUNDING Support was provided by Novartis and GlaxoSmithKline as part of an investigator-initiated study