High-dose-androgen-induced autophagic cell death to suppress the Enzalutamide-resistant prostate cancer growth via altering the circRNA-BCL2/miRNA-198/AMBRA1 signaling.

Androgen deprivation therapy (ADT) is a gold standard treatment for advanced PCa. However, most patients eventually develop the castration-resistant prostate cancer (CRPC) that progresses rapidly despite ongoing systemic androgen deprivation. While early studies indicated that high physiological doses of androgens might suppress rather than promote PCa cell growth in some selective CRPC patients, the exact mechanism of this opposite effect remains unclear. Here we found that Enzalutamide-resistant (EnzR) CRPC cells can be suppressed by the high-dose-androgen (dihydrotestosterone, DHT). Mechanism dissection suggested that a high-dose-DHT can suppress the circular RNA-BCL2 (circRNA-BCL2) expression via transcriptional regulation of its host gene BCL2. The suppressed circRNA-BCL2 can then alter the expression of miRNA-198 to modulate the AMBRA1 expression via direct binding to the 3'UTR of AMBRA1 mRNA. The consequences of high-dose-DHT suppressed circRNA-BCL2/miRNA-198/AMBRA1 signaling likely result in induction of the autophagic cell death to suppress the EnzR CRPC cell growth. Preclinical studies using in vivo xenograft mouse models also demonstrated that AMBRA1-shRNA to suppress the autophagic cell death can weaken the effect of high-dose-DHT on EnzR CRPC tumors. Together, these in vitro and in vivo data provide new insights for understanding the mechanisms underlying high-dose-DHT suppression of the EnzR CRPC cell growth, supporting a potential therapy using high-dose-androgens to suppress CRPC progression in the future.

Efficacy and safety of bipolar androgen therapy in castration-resistant prostate cancer following abiraterone or enzalutamide resistance: A systematic review.

Bipolar androgen therapy (BAT) is a new endocrinologic treatment for castration-resistant prostate cancer (CRPC) that can restore some patients' sensitivity to drugs such as abiraterone (Abi) and enzalutamide (Enz). We performed a meta-analysis using STATA16. Sensitivity analyses were performed by examining the effects of individual studies using different effect models and detecting any publication bias using the Harbord test. In a total of 108 unique records, ten studies were included in the final meta-analysis. Participants who underwent BAT achieved a PSA50 response rate of 27% (95%CI [0.22,0.31], I2=17.98%), ORR of 34% (95%CI [0.24,0.43], I2=0), and incidence of AEs (grade≥3) of 14% (95%CI [0.09,0.19], I2=0). Patients who completed BAT proceeded to AR-targeted therapy (Abi or Enz) and achieved a PSA50 response rate of 57% (95% CI [0.36,0.78], I2=0). Patients with prior Enz resistance had a stronger impact on the PSA50 of AR-target therapy rechallenge. The results of this meta-analysis indicate that BAT is a safe and effective treatment for patients who have progressed after Abi or Enz. BAT can trigger the resensitization of patients with CRPC to subsequent endocrine therapy and improve the overall survival of patients and their quality of life.

Histone acetyltransferase 1 upregulates androgen receptor expression to modulate CRPC cell resistance to enzalutamide.

Castration-resistant prostate cancer (CRPC) is the latest stage of PCa, and there is almost no effective treatment available for the patients with CRPC when next-generation androgen deprivation therapy drugs, such as enzalutamide (ENZ), fail. The androgen receptor (AR) plays key roles in PCa and CRPC progression and drug resistance. Histone acetyltransferase 1 (HAT1) has recently been reported to be highly expressed in some tumors, such as lung carcinoma. However, what relationship between the AR and HAT1, and whether or how HAT1 plays roles in CRPC progression and drug resistance remain elusive. In the present study, we found that HAT1 is highly expressed in PCa cells, and the overexpression of HAT1 is linked with CRPC cell proliferation. Moreover, the HAT1 expression is positively correlated with the expression of AR, including both AR-FL (full-length) and AR-V7 (variant 7), which is mainly mediated by a bromodomain containing protein 4 (BRD4) -mediated pathway. Furthermore, knockdown of HAT1 can re-sensitize the response of CRPC cells to ENZ treatment in cells and mouse models. In addition, ascorbate was observed to decrease AR expression through downregulation of HAT1 expression. Collectively, our findings reveal a novel AR signaling regulation pathway in PCa and CRPC and suggest that HAT1 serves as a critical oncoprotein and an ideal target for the treatment of ENZ resistance in CRPC patients.

Long Non-coding RNA AFAP1-AS1 Facilitates Prostate Cancer Progression by Regulating miR-15b/IGF1R Axis.

BACKGROUND: Prostate cancer (PCa) is a commonly diagnosed malignant cancer and is the second- highest cause of cancer death in men worldwide. Enzalutamide is the second-generation inhibitor of androgen receptor signaling and is the fundamental drug for the treatment of advanced PCa. However, the disease will eventually progress to metastatic castration-resistant prostate cancer (CRPC) and aggressive neuroendocrine prostate cancer (NEPC) because of androgen-deprivation therapy (ADT) resistance. The aim of the study was to investigate the role of long non-coding RNA (lncRNA) AFAP1-AS1 in ADT resistance. METHODS: Quantitative real-time PCR analysis (qPCR) was used to assess the expression of AFAP1-AS1 in PCa cell lines and tissues. Cell proliferation and invasion were assessed after AFAP1-AS1 knockdown using Cell Counting Kit (CCK)-8 and Transwell assay, respectively. A dual-luciferase reporter gene assay was carried out to validate the regulatory relationship among AFAP1-AS1, microRNA (miR)-15b, and insulin-like growth factor1 receptor (IGF1R). RESULTS: AFAP1-AS1 level was markedly increased in castration-resistant C4-2 cells and NE-like cells (PC3, DU145, and NCI-H660), compared with androgen-sensitive LNCaP cells. Enzalutamide treatment increased the expression of AFAP1-AS1 in vitro and in vivo. Functionally, AFAP1-AS1 knockdown repressed tumor cell proliferation and invasion. Mechanistically, AFAP1-AS1 functioned as an oncogene in PCa through binding to miR-15b and destroying its tumor suppressor function. Finally, we identified that AFAP1-AS1 up-regulated IGF1R expression by competitively binding to miR-15b to de-repress IGF1R. CONCLUSION: AFAP1-AS1 facilitates PCa progression by regulating miR-15b/IGF1R axis, indicating that AFAP1-AS1 may serve as a diagnostic biomarker and therapeutic target for PCa.

Who suffered most after deaths due to COVID-19? Prevalence and correlates of prolonged grief disorder in COVID-19 related bereaved adults.

BACKGROUND: Deaths by COVID-19 have left behind nearly 12 million recent bereaved individuals worldwide and researchers have raised concerns that the circumstances of COVID-19 related deaths will lead to a rise prevalence of prolonged grief disorder (PGD) cases. However, to date, no studies have examined the prevalence of PGD among people bereaved due to COVID-19. This study aimed to estimate the prevalence of PGD and investigated demographic and loss-related factors associated with prolonged grief symptoms among Chinese individuals bereaved due to COVID-19. METHODS: This was a cross-sectional online survey conducted between September 1 and October 3, 2020. A total of 422 Chinese participants (55.5% males; 32.73 [9.31] years old) who lost a close person due to COVID-19 participated in the study. Demographic and loss-related information was collected, and self-reported prolonged grief symptoms were measured by a 13-item International Prolonged Grief Disorder Scale (IPGDS: 1-65) and a 17-item Traumatic Grief Inventory Self Report (TGI-SR: 1-85). Multiple linear regression analysis was used to determine the associated factors of levels of grief symptoms. RESULTS: Prevalence of PGD was 37.8% screened by IPGDS and 29.3% by TGI-SR. No difference was found in levels of grief symptoms between participants whose close one died more than 6 months ago and those who experienced the loss less than 6 months ago. More severe prolonged grief symptoms assessed by IPGDS was associated with losing a close person by COVID-19 rather than complications (B: 5.35; 95% CI: 0.54-10.05), losing a partner (B: 7.80; 95% CI: 3.24-12.37), child (B: 8.15; 95% CI: 1.03-15.26), and parent (B: 5.49; 95% CI: 1.49-9.48) rather than losing a relative or a person with other relationship, feeling more traumatic about the loss (B: 1.71; 95% CI: 0.52-2.90), being closer with the deceased (B: 1.60; 95% CI: 0.34-2.86). Moreover, Losing a grandparent (B: 6.62; 95% CI: 0.53-12.71) and having more conflicts with the deceased (B: 1.05; 95% CI: - 0.008-2.11) were related to higher levels of grief symptoms assessed by TGI-SR. CONCLUSIONS: Echoing researchers' concerns, the prevalence of PGD is high among people bereaved due to COVID-19. Individuals with a higher risk of developing PGD should be identified and bereavement support should be offered as early as possible.

Suppressing BCL-XL increased the high dose androgens therapeutic effect to better induce the Enzalutamide-resistant prostate cancer autophagic cell death.

Most patients with advanced prostate cancer (PCa) initially respond well to androgen deprivation therapy (ADT) with antiandrogens, but most of them eventually become resistant to ADT. Here, we found that the antiandrogen Enzalutamide-resistant (EnzR) PCa cells can be suppressed by hyper-physiological doses of the androgen DHT. Mechanism dissection indicates that while androgens/androgen receptor (AR) can decrease BCL-2 expression to induce cell death, yet they can also simultaneously increase anti-apoptosis BCL-XL protein expression via decreasing its potential E3 ubiquitin ligase, PARK2, through transcriptionally increasing the miR-493-3p expression to target PARK2. Thus, targeting the high dose DHT/AR/miR-493-3p/PARK2/BCL-XL signaling with BCL-XL-shRNA can increase high-dose-DHT effect to better suppress EnzR cell growth via increasing the autophagic cell death. A preclinical study using in vivo mouse model also validated that suppressing BCL-XL led to enhance high dose DHT effect to induce PCa cell death. The success of human clinical trials in the future may help us to develop a novel therapy using high dose androgens to better suppress CRPC progression.

A Novel Androgen-Induced lncRNA FAM83H-AS1 Promotes Prostate Cancer Progression via the miR-15a/CCNE2 Axis.

Prostate cancer (PCa) is one of the most common types of tumors among males worldwide. However, the roles of long noncoding RNAs (lncRNAs) in PCa remain unclear. This study shows that lncRNA FAM83H-AS1 is upregulated in prostate adenocarcinoma, bladder urothelial carcinoma, and kidney renal papillary cell carcinoma samples. Androgen receptor (AR) signaling plays the most important role in PCa tumorigenesis and development. In this study, the results validate that AR signaling is involved in upregulating FAM83H-AS1 expression in PCa cells. Loss-of-function assays demonstrate that FAM83H-AS1 acts as an oncogene in PCa by modulating cell proliferation, cell cycle, and migration. Bioinformatics analysis demonstrates that FAM83H-AS1 is remarkably related to the regulation of the cell cycle and DNA replication through affecting multiple regulators related to these pathways, such as CCNE2. Mechanically, we found that FAM83H-AS1 plays its roles through sponging miR-15a to promote CCNE2 expression. These findings indicate that FAM83H-AS1 is a novel diagnostic and therapeutic marker for PCa.

Androgen dihydrotestosterone (DHT) promotes the bladder cancer nuclear AR-negative cell invasion via a newly identified membrane androgen receptor (mAR-SLC39A9)-mediated Gαi protein/MAPK/MMP9 intracellular signaling.

While androgens may function via nuclear androgen receptor (nAR) to increase bladder cancer (BCa) progression, the impact of androgens on muscle invasive BCa, which contains nearly 80% nAR-negative cells, remains unclear. To dissect the androgens potential impacts on these nAR-negative muscle invasive BCa, we first found that the androgens, dihydrotestosterone (DHT) might function via a novel membrane AR (mAR-SLC39A9) to increase nAR-negative BCa cell migration and invasion. Mechanism dissection revealed that DHT/mAR-SLC39A9 might function by altering Gαi protein-mediated MAPK/MMP9 intracellular signaling to increase nAR-negative BCa cell migration and invasion. Preclinical studies using multiple in vitro nAR-negative BCa cell lines and an in vivo mouse model all demonstrated that targeting this newly identified DHT/mAR-SLC39A9/Gαi/MAPK/MMP9 signaling with small molecules mAR-SLC39A9-shRNA or Gαi-shRNA, and not the classic antiandrogens including enzalutamide, bicalutamide, or hydroxyflutamide, could suppress nAR-negative BCa cell invasion. Results from human clinical samples surveys also indicated the positive correlation of this newly identified DHT/mAR signaling with BCa progression and prognosis. Together, these results suggest that androgens may not only function via the classic nAR to increase the nAR-positive BCa cell invasion, they may also function via this newly identified mAR-SLC39A9 to increase the nAR-negative/mAR-positive BCa cell invasion.

CircRNA-UCK2 Increased TET1 Inhibits Proliferation and Invasion of Prostate Cancer Cells Via Sponge MiRNA-767-5p.

A majority of the patients with advanced prostate cancer initially respond to androgen deprivation therapy and enzalutamide therapy, but eventually enter the castration-resistant prostate cancer (CRPC) phase. Some studies have shown that the activation of other signalling pathways in CRPC cells replaces the function of the androgen receptor, as well as promotes cell metastasis and progression. However, the mechanisms underlying this side effect remain unclear. The present study aims to explore the continued progression of cells after enzalutamide resistance. Low expression of circRNA-UCK2 (circUCK2) was detected in enzalutamide-resistant (EnzR) cells. Moreover, miR-767-5p was found to be resistant to EnzR cells when the level of circUCK2 is increased. The decrease in free miR-767-5p increases the expression of TET1 protein through the post-transcriptional regulation of mRNA, thereby inhibiting cell invasion and proliferation. Knocking down circUCK2 in enzalutamide-sensitive cells reduces the concentration of TET1, thereby increasing cell invasion and proliferation. A preclinical study using in vivo mouse models also showed that a high expression of circUCK2 inhibited the EnzR cell growth. Thus, this study might aid in developing a novel therapy to better suppress the CRPC progression.

miR-1303 promotes the proliferation, migration and invasion of prostate cancer cells through regulating the Wnt/ß-catenin pathway by targeting DKK3.

MicroRNA-1303 (miR-1303) is involved in the tumorigenesis and progression of several cancers, and yet the role of miR-1303 in prostate cancer (PCa) and its underlying mechanism are unknown. To explore this issue, the present study aimed to use PCa tissues, cell lines and a PCa-engrafted mouse model to determine the expression and roles of miR-1303 in PCa. Furthermore, a series of experiments were conducted to explore the underlying mechanisms of action of miR-1303 in PCa cells. miR-1303 was demonstrated to be highly expressed in PCa tissues and cell lines. The level of miR-1303 expression was closely associated with higher Gleason scores and a more developed tumor stage in patients with PCa, and patients with higher levels of miR-1303 displayed a reduced overall survival rate. miR-1303 overexpression promoted the proliferation, migration and invasion of PCa cells. In vivo experiments showed that miR-1303 inhibition suppressed the growth of PCa tumors in mice. Additionally, dickkopf Wnt signaling pathway inhibitor 3 (DKK3) was identified as a target of miR-1303. Knockdown of miR-1303 suppressed the proliferation, migration and invasion of PCa cells, increased DKK3 expression, and inhibited the activity of the Wnt/ß-catenin pathway. In conclusion, miR-1303 may promote proliferation, migration and invasion of PCa cells through activating the Wnt/ß-catenin pathway by regulating DKK3 expression. These results indicated that miR-1303 may be considered as a potential biomarker for PCa treatment.

KDM5C is transcriptionally regulated by BRD4 and promotes castration-resistance prostate cancer cell proliferation by repressing PTEN.

Prostate cancer (PCa) is one of the leading causes of cancer-related death worldwide, and it is almost incurable once it has developed into castration-resistance prostate cancer (CRPC). However, the mechanisms underlying the oncogenesis of PCa and CRPC remain elusive. Lysine-specific histone demethylase 5C (KDM5C) is an important member of lysine demethylase family and has recently been found highly expressed in multiple cancer types. In this study, we reported that KDM5C was highly expressed in PCa and CRPC specimens, and the high expression promoted CRPC cell proliferation through repressing phosphatase and tensin homolog (PTEN) gene epigenetically. Moreover, KDM5C was transcriptionally upregulated by bromodomain-containing protein 4 (BRD4), and knockdown KDM5C sensitized the therapeutic effects of CRPC cells to the bromodomain and extraterminal (BET) inhibitor. Taken together, our study uncovers that the BRD4-KDM5C-PTEN may be a new oncogenic pathway in CRPC development, and KDM5C is a critical protein and could be an ideal target for CRPC treatment in this oncogenic pathway.

Preclinical study using circular RNA 17 and micro RNA 181c-5p to suppress the enzalutamide-resistant prostate cancer progression.

Androgen-deprivation therapy (ADT) with newly developed antiandrogen enzalutamide (Enz) may increase the castration-resistant prostate cancer (CRPC) patients survival an extra 4.8 months. Yet eventually most patients may fail with development of Enz resistance. While recent clinical studies indicated that the increased expression of the androgen receptor (AR) splicing variant ARv7 might have key roles for the development of Enz resistance in CRPC, its detailed mechanism, especially its linkage to the circular RNAs (circRNAs), a form of non-coding RNA, however, remains unclear. Here we found from human clinical sample survey that circRNA17 (hsa_circ_0001427) has a lower expression in higher Gleason score PCa, and results from in vitro cell lines studies also revealed the lower expression in CRPC C4-2 Enz-resistant (EnzR-C4-2) cells compared to their parental Enz-sensitive (EnzS-C4-2) cells. Mechanism dissection indicated that suppressing circRNA17 in EnzS-C4-2 cells increased ARv7 expression that might then lead to increase the Enz resistance and cell invasion. Mechanism dissection demonstrated that Enz could suppress the circRNA17 expression at the transcriptional level via suppressing transcription of its host gene PDLIM5, and circRNA17 could regulate ARv7 expression via altering the expression of miR-181c-5p that involved the direct binding of miR-181c-5p to the 3'UTR of ARv7. Preclinical study using in vivo mouse model with xenografted EnzR-CWR22Rv1 cells revealed that adding circRNA17 or miRNA-181c-5p could suppress the EnzR-CWR22Rv1 cells growth. Together, results from these preclinical studies suggest that circRNA17 may function as suppressor to alter the Enz sensitivity and cell invasion in CRPC cells via altering the miR-181c-5p/ARv7 signaling and targeting this newly identified signaling may help in the development of a better therapy to further suppress the EnzR cell growth.

Avoidance of Bereavement-Related Stimuli in Chinese Individuals Experiencing Prolonged Grief: Evidence from a Dot-Probe Task.

Background: Attentional bias refers to a preference for (e.g., vigilance) or a shifting away (e.g., avoidance) of one's focus with respect to specific stimuli. Accumulating evidence suggests that an attentional bias toward death/threat-related stimuli exists in bereaved individuals experiencing prolonged grief (PG). Measuring for different processing may reflect different cognitive characteristics. Therefore, this study sought to compare information-processing biases in Chinese individuals with high versus low levels of PG symptomatology at supraliminal and subliminal levels, respectively. Method: A 2 (grief level) × 2 (consciousness level) × 2 (word type) three-factor mixed design with supraliminal and subliminal tasks was utilized in the current study. Based on their Prolonged Grief Questionnaire-13 (PG-13) scores, 38 participants were included in the low-PG group, and 34 individuals were included in the high-PG group. All the participants completed a dot-probe task in which they were primed with death-related and life-related words paired with neutral stimuli. Results: High-PG individuals were slower in reacting to the death-related information in both supraliminal and subliminal tasks. After controlling for other symptoms in the backward deletion regression, PG-13 scores significantly predicted the avoidance tendency to death-related words in the supraliminal task, while anxiety was the best predictor of turning one's vision away from death-related stimuli in the subliminal trials. Conclusion: The results suggested that high PG is associated with a tendency to avoid death-related words. Future research is needed to explore interventions that address the avoidance of death-related stimuli among individuals with elevated, or diagnosable, levels of PG.

miR-221/222 promotes S-phase entry and cellular migration in control of basal-like breast cancer.

The miR-221/222 cluster has been demonstrated to function as oncomiR in human cancers. miR-221/222 promotes epithelial-to-mesenchymal transition (EMT) and confers tamoxifen resistance in breast cancer. However, the effects and mechanisms by which miR-221/222 regulates breast cancer aggressiveness remain unclear. Here we detected a much higher expression of miR-221/222 in highly invasive basal-like breast cancer (BLBC) cells than that in non-invasive luminal cells. A microRNA dataset from breast cancer patients indicated an elevated expression of miR-221/222 in BLBC subtype. S-phase entry of the cell cycle was associated with the induction of miR-221/222 expression. miRNA inhibitors specially targeting miR-221 or miR-222 both significantly suppressed cellular migration, invasion and G1/S transition of the cell cycle in BLBC cell types. Proteomic analysis demonstrated the down-regulation of two tumor suppressor genes, suppressor of cytokine signaling 1 (SOCS1) and cyclin-dependent kinase inhibit 1B (CDKN1B), by miR-221/222. This is the first report to reveal miR-221/222 regulation of G1/S transition of the cell cycle. These findings demonstrate that miR-221/222 contribute to the aggressiveness in control of BLBC.

MicroRNA-mediated cancer metastasis regulation via heterotypic signals in the microenvironment.

MicroRNAs (miRNAs) are thought to regulate tumor progression and metastasis via direct interaction with target genes within cells. Emerging evidence has demonstrated the secretion of miRNAs into environment via cancer cell exosomes, called "exosomal shuttle small RNA". Microenvironmental miRNAs are important mediators of cell-to-cell communication, and they play important roles in regulating cancer metastasis. RNA analysis indicates enrichment of the miRNA population in cell-culturing medium. miRNA-conditioned medium is able to mediate the function of miRNAs in regulating cancer cell migration and invasion. Here we combine our recent work with literature discussing multiple mechanisms through which exosomal miRNAs regulate cancer cell migration, invasion and metastasis. We summarize a heterotypic signaling pathway by which miRNA regulates the cellular secretion and tumor microenvironment in control of breast cancer cell migration and invasion. In conclusion, exosomal miRNAs are able to regulate cancer metastasis via heterotypic signals in the microenvironment.

miR-17/20 sensitization of breast cancer cells to chemotherapy-induced apoptosis requires Akt1.

The serine threonine kinase Akt1 has been implicated in the control of cellular metabolism, survival and growth. Herein, disruption of the ubiquitously expressed member of the Akt family of genes, Akt1, in the mouse, demonstrates a requirement for Akt1 in miRNA-mediated cellular apoptosis. The miR-17/20 cluster is known to inhibit breast cancer cellular proliferation through G1/S cell cycle arrest via binding to the cyclin D1 3'UTR. Here we show that miR-17/20 overexpression sensitizes cells to apoptosis induced by either Doxorubicin or UV irradiation in MCF-7 cells via Akt1. miR-17/20 mediates apoptosis via increased p53 expression which promotes Akt degradation. Akt1⁻/⁻ mammary epithelial cells which express Akt2 and Akt3 demonstrated increased apoptosis to DNA damaging agents. Akt1 deficiency abolished the miR-17/20-mediated apoptosis. These results demonstrated a novel pathway through which miR17/20 regulate p53 and Akt controlling breast cancer cell apoptosis.