Poor Prognosis In Prostate Cancer Research Articles

High SLC20A1 Expression Indicates Poor Prognosis in Prostate Cancer.

High expression of solute carrier family 20 member 1 (SLC20A1) indicates poor clinical outcomes for patients with breast cancer subtypes treated with endocrine therapy and radiotherapy. However, the association between SLC20A1 expression and clinical outcomes in prostate cancer remains to be determined. Open-source datasets (The Cancer Genome Atlas prostate, Stand Up to Cancer-Prostate Cancer Foundation Dream Team, and The Cancer Genome Atlas PanCancer Atlas) were downloaded and analyzed. SLC20A1 expression was analyzed in prostate cancer and normal prostate tissue. Survival analysis using Kaplan-Meier curves and Cox regression analysis were performed to examine patient prognosis, as well as the effects of endocrine therapy and radiotherapy on high SLC20A1 expression in patients with prostate cancer. SLC20A1 was higher in prostate cancer than in normal prostate tissues. High SLC20A1 expression predicted poor disease-free and progression-free survival. Following endocrine therapy, no significant difference in prognosis was observed between patients with high SLC20A1 and those with low SLC20A1 expression. However, following radiotherapy, high SLC20A1 expression tended to be associated with a poor clinical outcome. SLC20A1 may serve as a prognostic biomarker for prostate cancer, and the recommended treatment for patients with high SLC20A1 expression is endocrine therapy.

Morphometric parameters of pelvic lymph nodes in experimental metastatic prostate cancer

The study purpose. Identification of structural and functional changes in pelvic lymph nodes in experimental metastatic prostate cancer. Materials and methods. The study included 30 male mice aged 3 months. All animals ( n = 30) were divided into 2 groups. The first group (the main one, n = 20) included mice that had a model of metastatic prostate cancer created by transplanting an Ehrlich tumor into the prostate parenchyma. These animals were further divided into two equal subgroups: 1a ( n = 10) – mice were withdrawn from the experiment on day 7; 1b ( n = 10) – mice were withdrawn from the experiment on day 18. The second group ( n = 10) included mice that were not manipulated, they made up the control group. After the end of the experiment, morphological analysis of the prostate gland and regional (pelvic) lymph nodes in mice of both groups was performed using light microscopy. Statistical processing of the results was carried out using the Statistica 8.0 software package. The differences were considered statistically significant at p < 0.05. Results. When compared to the control group the mice of groups 1a and 1b, the prostate parenchyma was almost completely replaced by atypical cells, which demonstrates the presence of neoplastic processes in the prostate gland. In group 1a mice, the number of pelvic lymph nodes was 1.9 times as large, and in group 1b animals, this indicator was 2.7 times higher compared to the second group ( p < 0.01). In animals of the first group, the proportion of mast cells in the pelvic lymph nodes increased by 121 % compared to the control group ( p < 0.01). At the same time, we revealed a direct relationship of mast cells with the number of tumor cells and immunoblasts in the medullar sinuses, which indicates the participation of tissue basophils in tumor metastasis. We also recorded a significant increase in the area of the medullar sinuses of regional lymph nodes in animals of groups 1a by 12.4 % ( p < 0.05) and 1b by 20.2 % ( p < 0.01) against the background of an increase in the number of mast cells in this zone compared to the control group, which indicates the possible participation of mast cells in lymphangiogenesis. Conclusion. Mast cells can potentially play a role in the development of malignant neoplasms of the prostate gland. The number of mast cells increases in pelvic lymph nodes in animals with a created model of metastatic prostate cancer. The obtained direct dependence of the increase in the number of mast cells and the increase in the number of tumor cells with immunoblasts suggests the participation of tissue basophils in the spread of metastases. It can be assumed that infiltration of lymph nodes by mast cells may correlate with a poor prognosis of prostate cancer, since these granulocytes contribute to tumor metastasis.

Abstract A016: Mechanism of hypoxia-induced centrosome loss in early prostate cancer

Abstract PURPOSE: We aim to understand cellular and microenvironmental determinants of chromosomal instability in prostate cancer and use these findings as prognostic biomarkers portending aggressive disease. Disease transitions during prostate cancer progression are accompanied by bursts of chromosomal instability (CIN), including chromosomal translocations, oncogene amplifications, and chromothripsis. While high CIN correlates with most metrics of aggressive disease, we lack a mechanistic understanding of how CIN originates in prostate cancer. Recently, we discovered that low Gleason score, primary prostate tumors lack centrosomes, cytoplasmic organelles that ensure the fidelity of chromosome segregation by organizing the shape of the mitotic spindle. Experimental elimination of centrosomes in immortalized, non-tumorigenic prostate cell lines was sufficient to generate extensive CIN resulting in oncogenic transformation of these lines when sub-cutaneously injected into NSG mice. Because we identified centrosome loss as a potential driver of CIN, we sought to understand mechanisms that can trigger centrosome loss in the prostate. Although centrosome loss naturally occurs during the development of some tissues, for example centrosome elimination during oogenesis, the mechanisms that trigger loss are not known. Therefore, we first investigated microenvironmental changes in early prostate cancer as a potential cause. Hypoxia, pathologically low oxygen concentration, is common in the aging prostate due to loss of vasculature and is associated with poor prostate cancer prognosis and high CIN. Therefore, we hypothesized that hypoxic exposure induces centrosome loss in prostate cells. Indeed, we found that exposure to 1% oxygen concentrations leads to progressive centrosome loss in non-tumorigenic, immortalized prostate epithelial cell lines. Using functional assays in cultured cells, we found that hypoxia-induced centrosome loss is an active disassembly process mediated by confluence-dependent Hippo signaling but independent of Hypoxia-Inducible Factor (HIF) transcription. We conclude that hypoxia-induced centrosome disassembly is a plausible driver of CIN in early prostate cancer. At present, we are developing immunohistochemistry assays to identify centrosome loss and hypoxia in biopsy samples to confirm these discoveries. Recently, we have described a combinatorial staining pattern (GLUT3/GLUT1/CA-9) that reliably identifies hypoxic tissue in patient-derived xenografts from prostate tumors. We are coupling this with a new assay to identify the structural component of the centrosome, called the centriole, which is identifiable during both mitosis and interphase. Together, our in situ assays will allow us to determine the penetrance of hypoxia-induced centrosome loss and its association with aggressive prostate cancer. Citation Format: John M. Ryniawec, Gregory C. Rogers, Anne E. Cress. Mechanism of hypoxia-induced centrosome loss in early prostate cancer [abstract]. In: Proceedings of the AACR Special Conference: Advances in Prostate Cancer Research; 2023 Mar 15-18; Denver, Colorado. Philadelphia (PA): AACR; Cancer Res 2023;83(11 Suppl):Abstract nr A016.

Abstract A075: Characterizing novel aggressive prostate cancer subtypes associated with loss of chromosomes 8p and 16q

Abstract Roughly 15% of the 268,490 men newly diagnosed with prostate cancer (PCa) will die from the disease. Pinpointing the drivers of aggressive PCa is the first step to improve patient outcomes. Correlative analyses have linked genetic aberrations, including copy number alterations due to loss of large genomic regions, to poor prostate cancer prognosis. Many groups have connected the loss of chromosome 8p and 16q to aggressive PCa, yet the genes on these regions responsible for aggressive phenotypes are unknown. Mining TCGA data, we identified minimum consensus deletions and associated gene expression with disease recurrence to nominate 48 genes on 8p and 58 genes on 16q for further study. We designed a pooled double knockout library to test all pairwise gene combinations of the nominated 8p-16q genes. Gene pairs will be targeted by 16 paired crRNA cassettes consisting of four crRNAs per gene and paired in all combinations. This library will be combined with stably expressing Cas12a prostate epithelial cell lines to screen for gene combinations that drive excessive cell proliferation. This will help pinpoint specific PCa tumor suppressors in combined 8p and 16q loss. Citation Format: Gabriel A. Yette, James C. Costello, Scott D. Cramer. Characterizing novel aggressive prostate cancer subtypes associated with loss of chromosomes 8p and 16q [abstract]. In: Proceedings of the AACR Special Conference: Advances in Prostate Cancer Research; 2023 Mar 15-18; Denver, Colorado. Philadelphia (PA): AACR; Cancer Res 2023;83(11 Suppl):Abstract nr A075.

Elevated PSPC1 and KDM5C expression indicates poor prognosis in prostate cancer

Prostate cancer (PCa) remains the most commonly diagnosed cancer in men worldwide and is still the second leading cause of cancer-related death. One major cause of PCa development is epigenetic aberration, including histone modification. We have previously demonstrated that Lysine Demethylase 5C (KDM5C) plays an essential role in the development of PCa and drives PCa progression by promoting epithelial-mesenchymal transition. Epigenetic regulators often work in concert, for example, to regulate transcription. We identified Paraspeckle Component 1 (PSPC1) as an interacting protein of KDM5C, suggesting that these proteins might function together in PCa. Here, we systematically investigate the expression patterns of KDM5C and PSPC1 in 2 independent prostate cohorts (432 and 205 prostate tumors in total for PSPC1 and KDM5C, respectively) by immunohistochemistry. We demonstrate that the expression of PSPC1 correlates with that of KDM5C. In addition, PSPC1 is up-regulated in primary and metastatic PCa. Elevated PSPC1 expression correlates with a higher-grade group and an advanced T-stage. Patients with high PSPC1 expression have a worse biochemical recurrence-free survival. In addition, PSPC1 expression is an independent prognostic parameter. Our data indicate that KDM5C and PSPC1 are involved in PCa progression, and therapeutic inhibition of KDM5C and PSPC1 by selective compounds might be a promising approach for the treatment of PCa.

SALL4 correlates with proliferation, metastasis, and poor prognosis in prostate cancer by affecting MAPK pathway.

The mechanism involved in prostate cancer (PCa) metastasis is still poorly understood, and several oncogenes are known to regulate this process. However, the role of spalt-like transcription factor 4 (SALL4) in PCa metastasis remains unclear. We performed RNA-sequencing to compare the mRNA expression profiles of seven localized PCa tissues and six metastatic PCa tissues. SALL4 was then identified and compared in the localized PCa and metastatic PCa. Immunohistochemical studies, qRT-PCR, and Western blot were performed to analyze the expression of SALL4 in PCa patients and cell lines. SALL4 expression and its relevance to clinical traits and prognosis were further explored in the TCGA database and in our 68 clinical samples. Subsequently, we knocked down SALL4 in DU145 and PC3 cells and performed a series of functional assays to explore the effect of SALL4 on PCa progression. Finally, protein levels of SALL4 and core components of the MAPK pathway were measured by Western blot, and cells were treated with PD0325901 to observe proliferation and metastasis. Significantly higher expression of SALL4 was found in metastatic PCa than in localized PCa. In addition, high SALL4 expression was significantly associated with high pathological T stage, N stage, Gleason score, and poor disease-free survival in TCGA database and in our clinical samples. Functional studies indicated that knockdown of SALL4 in DU145 and PC3 inhibited proliferation, migration, and angiogenesis. Furthermore, the ERK and P38 protein phosphorylation significantly reduced after knockdown of SALL4 in DU145 and PC3, indicating the inactivation of the MAPK signaling pathway. Finally, the proliferation and migration ability of DU145 and PC3 cells were significantly decreased after PD0325901 treatment. SALL4 predicts unfavorable outcome and is closely associated with PCa progression, suggesting that SALL4 may be a promising prognostic marker and potential therapeutic target for PCa.

Abstract 3070: Leveraging oxysterol sulfation by SULT2B1b sulfotransferase and liver X receptor inactivation to suppress advanced prostate cancer

Abstract Advanced prostate cancer is a heterogeneous disease driven by diverse genetic alterations, with metastasis and lethal progression as the inevitable outcome. We observed that a subset of clinical primary prostate cancer is markedly reduced for SULT2B1b (SULT2B) sulfotransferase, which is an oxysterol-sulfating enzyme. Metastasized castration-resistant prostate cancer (CRPC) uniformly lacks SULT2B. Oxysterols are oxidized cholesterol metabolites and in agonist function, they activate liver X receptors (LXRα/β), which are members of the nuclear receptor family and regulators of lipogenesis, cholesterol homeostasis and immune functions. LXR signaling is enzymatically inhibited by SULT2B activity since sulfated oxysterols are LXR-inert. We previously reported that genetic silencing of SULT2B led to escalated CRPC proliferation; enhanced xenograft tumor growth; increased cell migration, invasion; reduced stiffness, adhesiveness; and EMT activation. SULT2B-depleted CRPC cells showed robust upregulation of AKR1C3 aldo-keto reductase and AKR1C3-dependent activation of the ERK1/2 survival signal. AKR1C3 regulates intratumoral androgen biosynthesis, and it is known to be elevated in advanced prostate cancer. In the current study, we validate our previous result by showing that ectopic expression of SULT2B caused AKR1C3 reduction in CRPC cells. Mechanistically, we observed that enhanced AKR1C3 expression in SULT2B-depleted cells was prevented upon genetic or pharmacologic inactivation of LXR. In addition, ERRα, another non-steroid nuclear receptor, was reduced in LXR-inactivated cells and notably, AKR1C3 was reduced in CRPC cells upon ERRα degradation by an ERRα-selective PROTAC. The LXR dependence of ERRα and AKR1C3 expression was observed in both androgen receptor expressing and non-expressing CRPC cells. Conclusion & Translational Significance: Above results reveal a novel LXR-ERRα-AKR1C3-ERK axis which is activated in SULT2B-deficient CRPC cells irrespective of the androgen receptor status of these cells. Notably, elevated ERRα portends poor prognosis for prostate cancer and cholesterol is an ERRα agonist. Considering that statin can diminish ERRα activity (PMID 26777690) and AKR1C3 inhibitors are in clinical trials, this novel axis revealed from our study may be actionable for the clinical interception of the progression in SULT2B-low advanced prostate cancer. Citation Format: Bobae Park, Katarzyna Knapczyk-Stwora, Yaguang Liu, Chung S. Song, Bandana Chatterjee. Leveraging oxysterol sulfation by SULT2B1b sulfotransferase and liver X receptor inactivation to suppress advanced prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3070.

Abstract 1723: Ferroptosis is a novel therapeutic target for RB1 deficient lethal prostate cancer

Abstract Background: Although the development of next-generation antiandrogens has significantly extended the survival time of patients with metastatic castration-resistant prostate cancer (mCRPC), drug resistance inevitably developed over time. Therefore, the identification of novel therapeutic strategies targeting mCRPC is urgent. RB1 deficiency is a common genetic event and contributes to the development of therapy resistance and poor prognosis in prostate cancer. However, effective therapies against RB1-deficient lethal prostate cancer remain elusive. Here we determined how RB1 regulates the sensitivity of prostate cancer cells to ferroptosis, a form of regulated cell death driven by iron-dependent lipid peroxidation, and whether we can exploit ferroptosis for the treatment of RB1 deficient lethal prostate cancer. Methods: To determine how RB1 regulates ferroptosis in prostate cancer, we generated RB1 stable knockdown prostate cancer cell lines using lentivirus-delivered shRNAs. We compared cellular sensitivity to ferroptosis and associated lipid peroxidation between control and RB1 stable knockdown prostate cancer cells. Using western blotting, qPCR, and ChIP analyses, we examined the regulation of ferroptosis by RB1. We also evaluated the therapeutic efficacy of ferroptosis inducers in cell-derived xenograft, patient-derived xenograft, and genetically engineered mouse models. Results: Our studies revealed that RB1 deficiency sensitizes prostate cancer cells to ferroptosis. Mechanistically, we found that the E2F family of transcription factors directly binds and activates the ACSL4 promoter and that RB1 inhibits ferroptosis by suppressing E2F-mediated ACSL4 transcriptional activation. More importantly, our preclinical studies demonstrated that induction of ferroptosis by JKE-1674, a recently discovered ferroptosis inducer, significantly blocks RB1 deficient prostate tumor growth and metastasis, and improves the overall survival of mice in the absence of obvious toxicity. Conclusions: Our findings uncover an RB1/E2F/ACSL4 molecular axis that governs ferroptosis and also suggest a new approach to the treatment of RB1-deficient lethal prostate cancer. Citation Format: Mu-En Wang, Jiaqi Chen, Yi Lu, Jinjin Wy, Jianhong Ou, John Asara, Andrew Armstrong, Qianben Wang, Lei Li, Yuzhuo Wang, Jiaoti Huang, Ming Chen. Ferroptosis is a novel therapeutic target for RB1 deficient lethal prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1723.

Somatic and germline aberrations in homologous recombination repair genes in Chinese prostate cancer patients.

Somatic and germline aberrations in homologous recombinant repair (HHR) genes are associated with increased incidence and poor prognosis for prostate cancer. Through next-generation sequencing of prostate cancer patients across all clinical states from north China, here the authors identified a somatic mutational rate of 3% and a germline mutational rate of 3.9% for HRR genes using 200 tumor tissues and 714 blood specimens. Thus, mutational rates in HRR genes were lower compared with previous studies. Homologous recombination repair deficiency is associated with higher risk and poorer prognosis for prostate cancer. However, the landscapes of somatic and germline mutations in these genes remain poorly defined in Chinese patients, especially for those with localized disease and those from north part of China. In this study, we explore the genomic profiles of these patients. We performed next-generation sequencing with 200 tumor tissues and 714 blood samples from prostate cancer patients at Peking University First Hospital, using a 32 gene panel including 19 homologous recombination repair genes. TP53, PTEN, KRAS were the most common somatic aberrations; BRCA2, NBN, ATM were the most common germline aberrations. In terms of HRR genes, 3% (6/200) patients harbored somatic aberrations, and 3.8% (28/714) patients harbored germline aberrations. 98.0% (196/200) somatic-tested and 72.7% (519/714) germline tested patients underwent prostatectomy, of which 28.6% and 42.0% had Gleason scores ≥8 respectively. Gleason scores at either biopsy or prostatectomy were predictive for somatic aberrations in general and in TP53; while age of onset <60 years old, PSA at diagnosis, and Gleason scores at biopsy were clinical factors associated with positive germline aberrations in BRCA2/ATM. Our results showed a distinct genomic profile in homologous recombination repair genes for patients with prostate cancer across all clinical states from north China. Clinicians may consider to expand the prostate cancer patients receiving genetic tests to include more individuals due to the weak guiding role by the clinical factors currently available.

ARPC1A correlates with poor prognosis in prostate cancer and is up-regulated by glutamine metabolism to promote tumor cell migration, invasion and cytoskeletal changes

ObjectiveThis study aimed to identify potential biomarkers for prostate cancer (PCa) progression and metastasis, and to discern their biological functions.MethodsBioinformatics methods were used to screen for hub genes. The expression level of key hub genes in PCa was determined and their prognostic significance was examined. A series of functional assays were performed to investigate the function of the highest-ranking hub gene.ResultsActin related protein 2/3 complex subunit 1A (ARPC1A) was identified as the hub gene. ARPC1A was highly expressed in PCa tissues and cell lines, and was an independent prognostic factor for predicting biochemical recurrence after radical prostatectomy and overall survival of PCa patients. Knockdown of ARPC1A inhibited PCa cell migration, invasion and cytoskeleton formation, but had no impact on cell proliferation and cell cycle progression. In vivo, ARPC1A overexpression promoted lung metastasis of PCa, but had no efffect on tumor growth. Additionally, glutamine metabolism was identified as an upstream regulator of ARPC1A, and promoted migration, invasion and cytoskeletal changes of PCa cell through ARPC1A.ConclusionThese findings suggested that ARPC1A, which correlates with poor prognosis in PCa, functions downstream of glutamine metabolism to regulate cytoskeletal changes, cellular migration and cellular invasion in this disease.

GLIDR promotes the aggressiveness progression of prostate cancer cells by sponging miR-128–3p

Glioblastoma downregulated RNA (GLIDR) is a newly discovered long non-coding RNA (lncRNA) that its increased expression indicates a poor prognosis of prostate cancer (PCa). However, the effect of GLIDR on PCa cells is not clear. Our study investigated the role and molecular mechanism of GLIDR in PCa cells. The results showed that GLIDR expression levels were higher in PCa samples and cells than in control. GLIDR could regulate the invasive potential, epithelial-to-mesenchymal transition (EMT) and proliferation in PC-3 and LnCaP cells. Besides, GLIDR could weaken the inhibitory effects of miR-128-3p on invasion, EMT and proliferation in PCa cells. Western blotting proved that miR-128-3p affected the expression of EMT markers, such as E-cadherin, Snail and N-cadherin, and GLIDR could reversed the effects of miR-128-3p on the expression levels of EMT markers in PCa cells. In addition, knockdown of miR-128-3p stimulated the invasion, EMT, and proliferation in PCa cells, whereas these effects were reversed when GLIDR expression was knocked down. GLIDR knockdown inhibited the invasion, EMT, and proliferation in PCa cells, and GLIDR was shown to sponge miR-128-3p. Together, these results highlight GLIDR as a potential therapeutic target for the PCa treatment.

Tumor-infiltrating CD103+ cells define poor prognosis prostate cancer with favorable therapeutic response

Tumor-infiltrating CD103+ cells define poor prognosis prostate cancer with favorable therapeutic response

Novel, alternative splicing signature to detect lymph node metastasis in prostate adenocarcinoma with machine learning.

The presence of lymph node metastasis leads to a poor prognosis for prostate cancer (Pca). Recently, many studies have indicated that gene signatures may be able to predict the status of lymph nodes. The purpose of this study is to probe and validate a new tool to predict lymph node metastasis (LNM) based on alternative splicing (AS). Gene expression profiles and clinical information of prostate adenocarcinoma cohort were retrieved from The Cancer Genome Atlas (TCGA) database, and the corresponding RNA-seq splicing events profiles were obtained from the TCGA SpliceSeq. Limma package was used to identify the differentially expressed alternative splicing (DEAS) events between LNM and non-LNM groups. Eight machine learning classifiers were built to train with stratified five-fold cross-validation. SHAP values was used to explain the model. 333 differentially expressed alternative splicing (DEAS) events were identified. Using correlation filter and the least absolute shrinkage and selection operator (LASSO) method, a 96 AS signature was identified that had favorable discrimination in the training set and validated in the validation set. The linear discriminant analysis (LDA) was the best classifier after 100 iterations of training. The LDA classifier was able to distinguish between LNM and non-LNM with an area under the receiver operating curve of 0.962 ± 0.026 in the training set (D1 = 351) and 0.953 in the validation set (D2 = 62). The decision curve analysis plot proved the clinical application of the AS-based model. Machine learning combined with AS data could robustly distinguish between LNM and non-LNM in Pca.

Correlation of expression of Major Vault Protein with androgen receptor and immune checkpoint protein B7-H3, and with poor prognosis in prostate cancer.

Prostate cancer diagnosis and early stratification is an important aspect to avoid undertreatment of high-risk prostate cancer patients. Major Vault Protein (MVP) has been proposed as a prognostic biomarker in prostate cancer. PTEN and the immune checkpoint protein B7-H3 interact with MVP and are important in prostate cancer progression and therapy response. We evaluated the expression of MVP by immunohistochemistry of tissue microarray samples from a retrospective cohort consisting of 119 prostate cancer patients. We correlated the protein expression of MVP with clinicopathological characteristics, and protein expression of androgen receptor (AR), PTEN, immune checkpoint proteins B7-H3 and PD-L1. We found MVP to be expressed in 53% of prostate tumors, and correlated positively with biochemical recurrence (ρ=0.211/p=0.021). Furthermore, we found positive correlation of MVP expression with expression of AR (ρ=0.244/p=0.009) and the immune checkpoint protein B7-H3 (ρ=0.200/p=0.029), but not with PD-L1 (ρ=0.152/p=0.117) or PTEN expression (ρ=-0.034/p=0.721). Our findings support the notion that expression of MVP is associated with poor prognosis in prostate cancer. The correlation between MVP and immune checkpoint protein B7-H3 in prostate cancer suggests a role for MVP in immunoregulation and drug resistance.

Activation of the HNRNPA2B1/miR-93-5p/FRMD6 axis facilitates prostate cancer progression in an m6A-dependent manner.

It is becoming increasingly clear that N6-methyladenosine (m6A) plays a key role in post-transcriptional modification of eukaryotic RNAs in cancer. The regulatory mechanism of m6A modifications in prostate cancer is still not completely elucidated. Heterogeneous nuclear ribonucleoprotein A2/B1 (HNRNPA2B1), an m6A reader, has been revealed to function as an oncogenic RNA-binding protein. However, its contribution to prostate cancer progression remains poorly understood. Here, we found that HNRNPA2B1 was highly overexpressed and correlated with a poor prognosis in prostate cancer. In vitro and in vivo functional experiments demonstrated that HNRNPA2B1 knockout impaired proliferation and metastasis of prostate cancer. Mechanistic studies indicated that HNRNPA2B1 interacted with primary miRNA-93 and promoted its processing by recruiting DiGeorge syndrome critical region gene 8 (DGCR8), a key subunit of the Microprocessor complex, in an METTL3-dependent mechanism, while HNRNPA2B1 knockout significantly restored miR-93-5p levels. HNRNPA2B1/miR-93-5p downregulated FERM domain-containing protein 6 (FRMD6), a cancer suppressor, and enhanced proliferation and metastasis in prostate cancer. In conclusion, our findings identified a novel oncogenic axis, HNRNPA2B1/miR-93-5p/FRMD6, that stimulates prostate cancer progression via an m6A-dependent manner.

TRIM59 is suppressed by androgen receptor and acts to promote lineage plasticity and treatment-induced neuroendocrine differentiation in prostate cancer.

The incidence of treatment-induced neuroendocrine prostate cancer (t-NEPC) has been greatly increasing after the usage of secondgeneration androgen receptor (AR) pathway inhibitors (ARPIs). Neuroendocrine differentiation (NED) is closely associated with ARPI treatment failure and poor prognosis in prostate cancer (PCa) patients. However, the molecular mechanisms of NED are not fully understood. Here we report that upregulation of TRIM59, a TRIM family protein, is strongly correlated with ARPI treatment mediated NED and shorter patient survival in PCas. AR binds to TRIM59 promoter and represses its transcription. ARPI treatment leads to a reversal of repressive epigenetic modifications on TRIM59 gene and the transcriptional restraint on TRIM59 by AR. Upregulated TRIM59 then drives the NED of PCa by enhancing the degradation of RB1 and P53 and upregulating downstream lineage plasticity-promoting transcription factor SOX2. Altogether, TRIM59 is negatively regulated by AR and acts as a key driver for NED in PCas. Our study provides a novel prognostic marker for PCas and shed new light on the molecular pathogenesis of t-NEPC, a deadly variant of PCa.

SiAKR1C3@PPA complex nucleic acid nanoparticles inhibit castration-resistant prostate cancer in vitro.

AKR1C3, as a crucial androgenic enzyme, implicates the androgen biosynthesis and promoting prostate cancer cell growth in vitro. This study provides a new gene therapy strategy for targeting AKR1C3 to treat castration-resistant prostate cancer. siAKR1C3@PPA is assembled from PEG3500, PAMAM, Aptamer-PSMA, and siRNA for AKR1C3. We analyzed the relationship between AKR1C3 expression and the survival rate of prostate cancer patients based on the GEPIA online database to perform disease-free survival, and found that AKR1C3 may be an important factor leading to poor prognosis in prostate cancer. Considering AKR1C3 as a therapeutic target for castration-resistant prostate cancer, we constructed a complex nucleic acid nanoparticle, siAKR1C3@PPA to investigate the inhibitory effect on castration-resistant prostate cancer. Aptamer-PSMA acts as a target to guide siAKR1C3@PPA into PSMA-positive prostate cancer cells and specifically down regulate AKR1C3. Cyclin D1 was decreased as a result of siAKR1C3@PPA treatment. Changes in Cyclin D1 were consistent with decreased expression of AKR1C3 in LNCaP-AKR1C3 cells and 22RV1 cells. Furthermore, in the LNCaP-AKR1C3 group, 1070 proteins were upregulated and 1015 proteins were downregulated compared to the LNCaP group according to quantitative 4D label-free proteomics. We found 42 proteins involved in cell cycle regulation. In a validated experiment, we demonstrated that PCNP and CINP were up-regulated, and TERF2 and TP53 were down-regulated by western blotting. We concluded that siAKR1C3@PPA may arrest the cell cycle and affect cell proliferation.

MAPK8IP2 is a potential prognostic biomarker and promote tumor progression in prostate cancer

BackgroundMAPK8IP2 is one of the JNK-interacting proteins (JIPs) family members, and is involved in the regulation of the JNK and P38 MAPK signaling pathways. MAPK8IP2 has been reported to be closely associated with several cancers. However, the biological function of MAPK8IP2 in prostate cancer (PCa) remains unclear.MethodsMAPK8IP2 expression in PCa and subgroups of PCa was analyzed by public databases. The prognostic role of MAPK8IP2 in prostate cancer was analyzed using the Cox regression method. The potential mechanism by which MAPK8IP2 affects PCa progression was investigated by utilizing public data, including genetic alteration, DNA methylation, m6A methylation, and immune infiltration data. We further performed in vitro assays to validate the effect of MAPK8IP2 on PCa cell proliferation, migration and invasion.ResultsMAPK8IP2 is highly expressed in PCa tissues. Overexpression of MAPK8IP2 is associated with adverse clinicopathological factors and a poor prognosis in PCa. Receiver operating curve analysis showed that MAPK8IP2 can distinguish PCa tissues from non-PCa tissues with a certain accuracy (AUC = 0.814). The MAPK8IP2 genetic alteration rate was 2.6% and MAPK8IP2 alterations correlated with a poor prognosis. We also found that CDK12 and TP53 mutations were associated with MAPK8IP2 expression. The DNA methylation level of MAPK8IP2 was higher in primary tumors than in normal tissues, and the high MAPK8IP2 DNA methylation group of PCa patients had poor survival. Enrichment analysis indicated that MAPK8IP2 was involved in the MAPK signaling pathway. In vitro, knockdown of MAPK8IP2 inhibited PCa cell proliferation, migration and invasion.ConclusionMAPK8IP2 is a potential target for PCa treatment and can serve as a novel biomarker for PCa diagnosis and prognosis evaluation.

121P ATM germline mutations in lethal prostate cancer

Germline mutations in the ataxia telangiectasia mutated (ATM) gene occur in 0.5-1% of the overall population and are associated with tumour predisposition. The clinical and pathologic features of ATM-mutated prostate cancer (PC) have not been well defined. Data suggest that they are associated with poor prognosis PC. Herein, we examine our cohort of sequenced mCRPC for germline ATM mutations in patients with advanced PC, and report on associated clinical features.

Polymorphic variants of the CASP3, CASP9, BCL-2 and NKX3-1 genes as candidate markers for prostate cancer susceptibility and poor prognosis.

There is an ongoing search for molecular markers that are specific, sensitive, and able to predict the stage of prostate cancer (PCa), which is the second most prevalent type of cancer in men worldwide. This study examined whether different single nucleotide polymorphisms (SNPs) were reliable markers of susceptibility to and prognosis of PCa in a sample of Brazilian patients. DNA samples were extracted from peripheral blood cells of 283 PCa patients and matched with samples from healthy controls. Single nucleotide polymorphisms (SNPs in four genes (BCL-2-rs2279115, CASP3-rs4647603, CASP9-rs1052571, and NKX3-1-rs11781886) were genotyped by real-time PCR using the TaqMan® probe. Odds Ratios with 95% confidence intervals were calculated for allelic and genotypic frequencies. The association between polymorphic variants, risk of developing PCa, and clinicopathological characteristics was analyzed by univariate and multivariate logistic regression analysis. SNPs in CASP3, CASP9, and NKX3-1 genes, either alone or in combination (BCL-2+NKX3-1 and CASP3+NKX3-1) were associated with the risk of developing PCa. Genotypes and tumor histopathological data indicated that the BCL-2, NKX3-1, and CASP3 allelic variants, either alone or combined in pairs, were associated with a poor prognosis of PCa. Genetic polymorphisms in CASP3, NKX3-1, and BCL-2 genes were associated with susceptibility to PCa. The SNPs in the three genes alone and the SNP in the BCL-2 gene combined with the other two genes were strongly associated with adverse outcomes in PCa patients and are promising candidates for molecular markers for PCa prognosis.