Luwei Cui Ming Liu Shicong Lai Huimin Hou Tongxiang Diao Dalei Zhang Miao Wang Yaoguang Zhang Jianye Wang 1Peking University Fifth School of Clinical Medicine, Beijing, People's Republic of China; 2Department of Urology, Beijing Hospital, National Center of Gerontology, Beijing, People’s Republic of China; 3Graduate School of Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, People’s Republic of China Background: Prostate cancer is the second leading cause of cancer-related deaths in Western countries. Most patients diagnosed with advanced prostate cancer can be treated with the main treatment: androgen deprivation therapy (ADT). The androgen receptor (AR) signaling axis plays a pivotal role in the progression of prostate cancer. However, most patients can ultimately progress to the castration-resistant prostate cancer (CRPC) stage within 2 years. At this stage, drugs targeting the AR signaling axis, including enzalutamide and abiraterone acetate, cannot prevent the progression of prostate cancer, thus predicting a poor prognosis. The molecular mechanism lies in the aberrant AR reactivation, which exhibits an adaptive response to ADT, such as the presence of AR splice variants. Thus, CRPC treatment remains a challenge. Purpose: In addition to the AR axis, a mechanism leading to this progression should be determined. The present study mainly compared palmitoylated proteins between androgentreated LNCaP cells and non-treated LNCaP cells by palmitoylome profiling, to illustrate the changes at proteomic levels. Materials and methods: To screen the androgen-induced palmitoylated proteins, we conducted proteomic experiments using clickable palmitate probe (Alk-C16) between three individual pairs of androgen-treated and non-treated LNCaP cells. Results: We identified 4351 unique peptides corresponding to 835 proteins, among them a number of these identified proteins were palmitoylated proteins, particularly eIF3L. Androgen treatment significantly increased the palmitoylation level of eIF3L, an individual subunit of eIF3. As an initiation factor, eIF3L plays a pivotal role in the translation of mRNAs encoding growth-promoting proteins by enhancing translation rates, thus controlling cell proliferation. Conclusion: In this study, we demonstrated that the regulation of eIF3L palmitoylation may provide new directions for the therapy of prostate cancer. Moreover, the increased level of androgen-induced eIF3L may be used as a biomarker for the diagnosis of early-stage prostate cancer.

Background: Prostate cancer is the second leading cause of cancer-related deaths in Western countries. Most patients diagnosed with advanced prostate cancer can be treated with the main treatment: androgen deprivation therapy (ADT). The androgen receptor (AR) signaling axis plays a pivotal role in the progression of prostate cancer. However, most patients can ultimately progress to the castration-resistant prostate cancer (CRPC) stage within 2 years. At this stage, drugs targeting the AR signaling axis, including enzalutamide and abiraterone acetate, cannot prevent the progression of prostate cancer, thus predicting a poor prognosis. The molecular mechanism lies in the aberrant AR reactivation, which exhibits an adaptive response to ADT, such as the presence of AR splice variants. Thus, CRPC treatment remains a challenge. Purpose: In addition to the AR axis, a mechanism leading to this progression should be determined. The present study mainly compared palmitoylated proteins between androgen-treated LNCaP cells and non-treated LNCaP cells by palmitoylome profiling, to illustrate the changes at proteomic levels. Materials and methods: To screen the androgen-induced palmitoylated proteins, we conducted proteomic experiments using clickable palmitate probe (Alk-C16) between three individual pairs of androgen-treated and non-treated LNCaP cells. Results: We identified 4351 unique peptides corresponding to 835 proteins, among them a number of these identified proteins were palmitoylated proteins, particularly eIF3L. Androgen treatment significantly increased the palmitoylation level of eIF3L, an individual subunit of eIF3. As an initiation factor, eIF3L plays a pivotal role in the translation of mRNAs encoding growth-promoting proteins by enhancing translation rates, thus controlling cell proliferation. Conclusion: In this study, we demonstrated that the regulation of eIF3L palmitoylation may provide new directions for the therapy of prostate cancer. Moreover, the increased level of androgen-induced eIF3L may be used as a biomarker for the diagnosis of early-stage prostate cancer.

Background Abiraterone and MDV3100 are two effective anticancer agents for prostate cancer, however, the mechanism of their downstream action remains undefined. Methods A dual fluorescent biosensor plasmid was transfected in LNCaP cells to measure mitophagy. The DNA of LNCaP cells was extracted and performed with quantitative real-time PCR to detect mitochondrial DNA copy number. JC-1 staining was utilized to detect the mitochondrial membrane potential and electron microscope was performed to analyze mitochondrial morphology. Moreover, the protein levels of mitochondrial markers and apoptotic markers were detected by western blot. At last, the proliferation and apoptosis of LNCaP cells were analyzed with CCK-8 assay and flow cytometry after abiraterone or MDV3100 treatment. Results Mitophagy was induced by abiraterone and MDV3100 in LNCaP cells. The low expression level of mitochondrial DNA copy number and mitochondrial depolarization were further identified in the abiraterone or MDV3100 treatment groups compared with the control group. Besides, severe mitochondria swelling and substantial autophagy-lysosomes were observed in abiraterone- and MDV3100-treated LNCaP cells. The expression of mitochondria-related proteins, frataxin, ACO2 and Tom20 were significantly downregulated in abiraterone and MDV3100 treated LNCaP cells, whereas the expression level of inner membrane protein of mitochondria (Tim23) was significantly upregulated in the same condition. Moreover, the proliferation of LNCaP cells were drastically inhibited, and the apoptosis of LNCaP cells was increased in abiraterone or MDV3100 treatment groups. Meanwhile, the addition of mitophagy inhibitor Mdivi-1 (mitochondrial division inhibitor 1) could conversely elevate proliferation and constrain apoptosis of LNCaP cells. Conclusions Our results prove that both abiraterone and MDV3100 inhibit the proliferation, promote the apoptosis of prostate cancer cells through regulating mitophagy. The promotion of mitophagy might enhance the efficacy of abiraterone and MDV3100, which could be a potential strategy to improve chemotherapy with these two reagents.

Background: Prostate adenocarcinoma (PCa) is a complex genetic disease, and the implementation of personalized treatment in PCa faces challenges due to significant inter- and intrapatient tumor heterogeneities. Objective: To systematically explore the genomic complexity of tumor cells with different Gleason scores (GSs) in PCa. Design, setting, and participants: We performed single-cell whole genome sequencing of 17 tumor cells from localized lesions with distinct GS and matched four normal samples from two prostatectomy patients. Outcome measurements and statistical analysis: All classes of genomic alterations were identified, including substitutions, insertions/deletions, copy number alterations, and rearrangements. Results and limitations: Significant spatial, intra- and intertumoral heterogeneities were observed at the cellular level. In the patient 1, all cells shared the same TP53 driver mutation, implying a monoclonal origin of PCa. In the patient 2, only a subpopulation of cells contained the TP53 driver mutation, whereas other cells carried different driver mutations, indicating a typical polyclonal model with separate clonal cell expansions. The tumor cells from different sides of prostate owned various mutation patterns. Considerable neoantigens were predicted among different cells, implying unknown immune editing components helping prostate tumor cells escaping from immune surveillance. Conclusions: There is a significant spatial genomic heterogeneity even in the same PCa patient. Our study also provides the first genome-wide evidence at single-cell level, supporting that the origin of PCa could be either polyclonal or monoclonal, which has implications for treatment decisions for prostate cancer. Patient summary: We reported the first single-cell whole genomic data of prostate adenocarcinoma (PCa) from different Gleason scores. Identification of these genetic alterations may help understand PCa tumor progression and clonal evolution. (C) 2018 Published by Elsevier B.V. on behalf of European Association of Urology.