Spermatozoa centriolar defects can result in abnormal zygote functions. Recently, a method to quantify spermatozoa centriolar defects was developed named Fluorescence-Based Ratiometric Analysis of Sperm Centrioles (FRAC). However, whether spermatozoa centriolar defects identified by FRAC can result in abnormal zygote functions was not tested. Here, we quantified spermatozoa centriolar defects using FRAC, and zygote centriole function was assessed by imaging Nucleolus Precursor Body (NPB) polarization which was based on the pattern of NPB polarization. Data was analyzed at couple and embryo levels. Subjects were divided into two groups: seven couples and 62 embryos with normal spermatozoa centrioles versus eight couples and 78 embryos with abnormal spermatozoa centrioles (140 embryos from 15 couples in total). Patterned NPB polarization was statistically significant in both couple- and embryo-level analyses (p < 0.0001 and p = 0.0024). These results suggest that the abnormal spermatozoa centrioles identified by FRAC may correlate with abnormal zygote centrosome function via NPB polarization scoring. This study provides a foundation for more extensive studies to test for FRAC's utility in assessing spermatozoa centriole quality.
The introduction of enzalutamide and abiraterone has led to improvement in the treatment of metastatic castration-resistant prostate cancer. However, acquired resistance to enzalutamide and abiraterone therapies frequently develops within a short period in many patients. In the present study, we developed enzalutamide-resistant prostate cancer cells in an effort to understand the mechanisms of resistance. Global gene-expression analysis showed that the steroid biosynthesis pathway is activated in enzalutamide-resistant prostate cancer cells. One of the crucial steroidogenic enzymes, AKR1C3, was significantly elevated in enzalutamide-resistant cells. In addition, AKR1C3 is highly expressed in metastatic and recurrent prostate cancer and in enzalutamide-resistant prostate xenograft tumors. LC/MS analysis of the steroid metabolites revealed that androgen precursors such as cholesterol, DHEA and progesterone, as well as androgens are highly upregulated in enzalutamide-resistant prostate cancer cells compared to the parental cells. Knockdown of AKR1C3 expression by shRNA or inhibition of AKR1C3 enzymatic activity by indomethacin resensitized enzalutamide-resistant prostate cancer cells to enzalutamide treatment both in vitro and in vivo. In contrast, overexpression of AKR1C3 confers resistance to enzalutamide. Furthermore, the combination of indomethacin and enzalutamide resulted in significant inhibition of enzalutamide-resistant tumor growth. These results suggest that AKR1C3 activation is a critical resistance mechanism associated with enzalutamide resistance; targeting intracrine androgens and AKR1C3 will overcome enzalutamide resistance and improve survival of advanced prostate cancer patients.
Introduction: Currently, there is limited evidence for the relationship of Exosome-based Prostate Intelliscore (EPI) and multiparametric magnetic resonance imaging (mpMRI) in stratifying risk for clinically significant prostate cancer. Using a retrospective cohort study design, we sought to characterize the relationship between these two noninvasive metrics and prostate biopsy outcome. Methods: Data were collected via electronic medical record for all patients who underwent EPI testing from 1 January 2019 to 3 February 2022 and had available medical records at a single mid-western university medical center. Positive test result was defined as >15.6 for EPI, ≥3 PI-RADS score and ≥3 + 4 Gleason Score for biopsy findings. Utility of EPI, mpMRI and combined use was characterized through calculation of sensitivity, specificity, positive predictive value, negative predictive value, and ROC analysis. Results: A total of 226 patients were identified as receiving EPI testing for risk stratification of clinically significant prostate cancer. Sensitivity for EPI was 91%, mpMRI was 90%, and the highest was combined use at 96%. With ROC analysis, AUC for EPI alone was 0.57 (95% CI, 0.47–0.67) and 0.78 (95% CI, 0.70–0.87) for mpMRI alone. With prior positive EPI result, AUC for combined use with mpMRI was 0.80 (95% CI, 0.71–0.89). Further subgroup analysis resulted in increased AUC values of EPI 0.67 (95% CI, 0.48–0.87), mpMRI 0.90 (95% CI, 0.76–1.0), and combined 0.90 (95% CI, 0.75–1.0) in the African American population. Discussion: We observed that the combined use of EPI and mpMRI led to an avoided biopsy in 43% of patients. Using both parameters increased the overall sensitivity and diagnostic accuracy in detecting clinically significant prostate cancer. The best test performance was observed in the African American cohort. Identifying optimal noninvasive tools to assess risk for prostate cancer is crucial to providing accurate and cost-effective care. Future study should utilize a prospective study design to further support the combined use of these metrics.
Abstract Prostate cancers (PCa) exhibit a unique metabolic profile with reliance on different forms of glucose metabolism at different stages of disease progression. Early stage PCa cells use the more efficient TCA cycle, while metastatic PCa cells switch to glycolysis (Warburg effect), leading to the accumulation of lactate. Lactate is exported out of the cells by monocarboxylate transporters (MCTs) to maintain redox balance. Such metabolic reprogramming can lead to gain-of-function mutations and affect drug sensitivity. Enzalutamide is a second-generation antiandrogen used for the treatment of metastatic castration-resistant PCa. However, resistance to Enzalutamide develops in most patients within 9-15 months. Since Warburg effect is a hallmark of metastatic PCa, we sought to understand whether lactate transport has any effect on Enzalutamide-resistance in PCa. We measured the expression of MCTs in parental and Enzalutamide-resistant C4-2B and 22RV1 cells and found that they are overexpressed in the Enzalutamide resistant subtypes. Based on this observation, we hypothesized that targeting lactate transport might be a potential strategy to overcome Enzalutamide-resistance in PCa cells. Using cell survival and cell proliferation assays, we found that MCT antagonists resensitized Enzalutamide resistant C4-2B and 22Rv1 cells to treatment with Enzalutamide. Using the Seahorse based glycolytic rate assay we found that these combination treatments significantly reduced the extracellular acidification rate by reducing the level of glycolysis in the Enzalutamide-resistant PCa cells. We also found that treatment with these antagonists either singly, or in combination with Enzalutamide suppressed xenograft growth in SCID mice bearing subcutaneously injected parental or Enzalutamide-resistant C4-2B cells. These findings led to the conclusion that targeting MCTs could be an attractive strategy to overcome Enzalutamide resistance in prostate cancer. Citation Format: Sayani Bhattacharjee, Jonathan P. Doan, Rebecca Wynn, Nagalakshmi Nadiminty. Targeting MCT inhibition to overcome enzalutamide resistance in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 393.