Activation of β-Catenin Cooperates with Loss of Pten to Drive AR-Independent Castration-Resistant Prostate Cancer

Dickkopf-1 (DKK1) drives growth and metastases in castration-resistant prostate cancer

Metastatic castration-resistant prostate cancer (mCRPC) is associated with a poor prognosis and remains an incurable fatal disease. Therefore, the identification of molecular markers involved in cancer progression is urgently needed to develop more-effective therapies. The present study investigated the role of the Wnt signaling modulator Dickkopf-1 (DKK1) in the growth and metastatic progression of mCRPC. DKK1 silencing through siRNA and deletion via CRISPR/Cas9 editing were performed in two different metastatic castration-resistant prostate cancer cell lines (PC3 and DU145). A xenograft tumor model was used to assess tumor growth and metastases. In in vitro experiments, both DKK1 silencing and deletion reduced cell growth and migration of both cell lines. DKK1 knockout clones (DKK1-KO) exhibited cell cycle arrest, tubulin reorganization, and modulation of tumor metastasis-associated genes. Furthermore, in DKK1-KO cells, E-cadherin re-expression and its membrane co-localization with β-catenin were observed, contributing to reduced migration; Cadherin-11, known to increase during epithelial-mesenchymal transition, was down-regulated in DKK1-KO cells. In the xenograft mouse model, DKK1 deletion not only reduced tumor growth but also inhibited the formation of lung metastases. In conclusion, our findings support the key role of DKK1 in the growth and metastatic dissemination of mCRPC, both in vitro and in vivo.

Development and Characterisation of a New Patient-Derived Xenograft Model of AR-Negative Metastatic Castration-Resistant Prostate Cancer

As the treatment landscape for prostate cancer gradually evolves, the frequency of treatment-induced neuroendocrine prostate cancer (NEPC) and double-negative prostate cancer (DNPC) that is deficient for androgen receptor (AR) and neuroendocrine (NE) markers has increased. These prostate cancer subtypes are typically refractory to AR-directed therapies and exhibit poor clinical outcomes. Only a small range of NEPC/DNPC models exist, limiting our molecular understanding of this disease and hindering our ability to perform preclinical trials exploring novel therapies to treat NEPC/DNPC that are urgently needed in the clinic. Here, we report the development of the CU-PC01 PDX model that represents AR-negative mCRPC with PTEN/RB/PSMA loss and CTNN1B/TP53/BRCA2 genetic variants. The CU-PC01 model lacks classic NE markers, with only focal and/or weak expression of chromogranin A, INSM1 and CD56. Collectively, these findings are most consistent with a DNPC phenotype. Ex vivo and in vivo preclinical studies revealed that CU-PC01 PDX tumours are resistant to mCRPC standard-of-care treatments enzalutamide and docetaxel, mirroring the donor patient's treatment response. Furthermore, short-term CU-PC01 tumour explant cultures indicate this model is initially sensitive to PARP inhibition with olaparib. Thus, the CU-PC01 PDX model provides a valuable opportunity to study AR-negative mCRPC biology and to discover new treatment avenues for this hard-to-treat disease.

Nuclear receptor NURR1 functions to promote stemness and epithelial-mesenchymal transition in prostate cancer via its targeting of Wnt/β-catenin signaling pathway

Dysregulated activation of Wnt/β-catenin signaling pathway is a frequent or common event during advanced progression of multiple cancers. With this signaling activation, it enhances their tumorigenic growth and facilitates metastasis and therapy resistance. Advances show that this signaling pathway can play dual regulatory roles in the control of cellular processes epithelial-mesenchymal transition (EMT) and cancer stemness in cancer progression. Aberrant activation of Wnt/β-catenin signaling pathway is shown to be common in prostate cancer and also castration-resistant prostate cancer (CRPC). However, the transcriptional regulators of this pathway in prostate cancer are still not well characterized. NURR1 (NR4A2) is an orphan nuclear receptor and plays an important role in the development of dopaminergic neurons. Previously, we have shown that NURR1 exhibits an upregulation in isolated prostate cancer stem-like cells (PCSCs) and a xenograft model of CRPC. In this study, we further confirmed that NURR1 exhibited an upregulation in prostate cancer and also enhanced expression in prostate cancer cell lines. Functional and molecular analyses showed that NURR1 could act to promote both in vitro (cancer stemness and EMT) and also in vivo oncogenic growth of prostate cancer cells (metastasis and castration resistance) via its direct transactivation of CTNNB1 (β-catenin) and activation of β-catenin to mediate the activation of Wnt/β-catenin signaling pathway. Moreover, we also demonstrated that NURR1 activity in prostate cancer cells could be modulated by small molecules, implicating that NURR1 could be a potential therapeutic target for advanced prostate cancer management.

An integrative proteomics approach identifies tyrosine kinase KIT as a therapeutic target for SPINK1-positive prostate cancer

Elevated serine peptidase inhibitor, Kazal type 1 (SPINK1) levels in ∼10%-25% of prostate cancer (PCa) patients associate with aggressive phenotype, for which there are limited treatment choices and dismal clinical outcomes. Using an integrative proteomics approach involving label-free phosphoproteome and proteome profiling, we delineated the downstream signaling pathways involved in SPINK1-mediated tumorigenesis and identified tyrosine kinase KIT as highly enriched. Furthermore, high to moderate levels of KIT expression were detected in ∼85% of SPINK1-positive PCa specimens. We show KIT signaling orchestrates SPINK1-mediated oncogenesis, and treatment with KIT inhibitor reduces tumor growth and metastases in preclinical mice models. Mechanistically, KIT signaling modulates WNT/β-catenin pathway and confers stemness-related features in PCa. Notably, inhibiting KIT signaling led to restoration of AR/REST levels, forming a feedback loop enabling SPINK1 repression. Overall, we uncover the role of KIT signaling downstream of SPINK1 in maintaining lineage plasticity and provide distinct treatment modalities for advanced-stage SPINK1-positive patients.

Exploring the Relationship between E-Cadherin and β-Catenin Cell Adhesion Proteins and Periacinar Retraction Clefting in Prostatic Adenocarcinoma

BACKGROUND

Periacinar retraction clefts represent a histopathological criterion supporting the diagnosis of prostatic adenocarcinoma. The origin of these clefts in prostatic adenocarcinoma remains unclear. Exploring the established functions of E-cadherin and β-catenin as intercellular adhesion proteins, and aiming to elucidate the origin of periacinar retraction clefting, we conducted a correlation study between the immunohistochemical expression of E-cadherin and β-catenin and the presence of periacinar retraction clefts in prostatic adenocarcinoma.

METHODS

We examined 53 cases of morphologically diagnosed prostatic adenocarcinoma, assessing both the neoplastic and adjacent nonneoplastic prostatic tissues for the existence and degree of periacinar retraction clefts. Additionally, we analyzed the immunohistochemical expression of E-cadherin and β-catenin proteins in prostatic tissue and explored their correlation with periacinar retraction clefts, and Gleason score, Grade Group, preoperative serum prostate specific-antigen (sPSA) levels, surgical margin status, and Tumor, Node, Metastasis (TNM) stage in prostatic adenocarcinoma.

RESULTS

Our study confirms that periacinar retraction clefting is significantly more extensive in prostatic adenocarcinoma than in nonneoplastic prostatic tissue (p < 0.001). We report a decreased expression of E-cadherin and β-catenin immunostaining in prostatic adenocarcinoma and a negative correlation with Gleason score and Grade Group. Periacinar retraction clefting positively correlated with E-cadherin and β-catenin ((rho = 0.350; p = 0.010) and (rho = 0.340; p = 0.012)) immunostaining in prostatic adenocarcinoma.

CONCLUSIONS

Periacinar retraction clefts stand out as a dependable criterion in the diagnosis of prostatic adenocarcinoma. E-cadherin and β-catenin proteins are potential markers indicative of tumor progression and invasiveness in prostatic adenocarcinoma. Our discovery of a positive correlation between immunostaining of E-cadherin and β-catenin proteins and periacinar retraction clefts in prostatic adenocarcinoma aligns with the notion that periacinar retraction clefting is more characteristic of Gleason Grade3 pattern in prostatic adenocarcinomas, whereas the immunohistochemical expression of E-cadherin and β-catenin shows a decrease with increasing histopathological tumor grade.

Inhibition of Wnt/β-catenin pathway overcomes therapeutic resistance to abiraterone in castration-resistant prostate cancer

Abiraterone acetate has been clinically approved for the treatment of patients with advanced-stage prostate cancer. It reduces testosterone production by blocking the enzyme cytochrome P450 17 alpha-hydroxylase. Despite improved survival outcomes with abiraterone, almost all patients develop therapeutic resistance and disease recurrence, progressing to a more aggressive and lethal phenotype. Bioinformatics analyses predicted activation of canonical Wnt/β-catenin and involvement of stem cell plasticity in abiraterone-resistant prostate cancer. Increased expression of androgen receptor (AR) and β-catenin and their crosstalk causes activation of AR target genes and regulatory networks for which overcoming acquired resistance remains a major challenge. Here we show that co-treatment with abiraterone and ICG001, a β-catenin inhibitor, overcomes therapeutic resistance and significantly inhibited markers of stem cell and cellular proliferation in abiraterone-resistant prostate cancer cells. Importantly, this combined treatment abrogated the association between AR and β-catenin; diminished SOX9 expression from the complex more prominently in abiraterone-resistant cells. In addition, combined treatment inhibited tumor growth in an in vivo abiraterone-resistant xenograft model, blocked stemness, migration, invasion, and colony formation ability of cancer cells. This study opens new therapeutic opportunity for advanced-stage castration-resistant prostate cancer patients.

Lineage Plasticity and Stemness Phenotypes in Prostate Cancer: Harnessing the Power of Integrated "Omics" Approaches to Explore Measurable Metrics

Prostate cancer (PCa), the most frequent and second most lethal cancer type in men in developed countries, is a highly heterogeneous disease. PCa heterogeneity, therapy resistance, stemness, and lethal progression have been attributed to lineage plasticity, which refers to the ability of neoplastic cells to undergo phenotypic changes under microenvironmental pressures by switching between developmental cell states. What remains to be elucidated is how to identify measurements of lineage plasticity, how to implement them to inform preclinical and clinical research, and, further, how to classify patients and inform therapeutic strategies in the clinic. Recent research has highlighted the crucial role of next-generation sequencing technologies in identifying potential biomarkers associated with lineage plasticity. Here, we review the genomic, transcriptomic, and epigenetic events that have been described in PCa and highlight those with significance for lineage plasticity. We further focus on their relevance in PCa research and their benefits in PCa patient classification. Finally, we explore ways in which bioinformatic analyses can be used to determine lineage plasticity based on large omics analyses and algorithms that can shed light on upstream and downstream events. Most importantly, an integrated multiomics approach may soon allow for the identification of a lineage plasticity signature, which would revolutionize the molecular classification of PCa patients.

MultiNEP: a multi-omics network enhancement framework for prioritizing disease genes and metabolites simultaneously

MOTIVATION

Many studies have successfully used network information to prioritize candidate omics profiles associated with diseases. The metabolome, as the link between genotypes and phenotypes, has accumulated growing attention. Using a "multi-omics" network constructed with a gene-gene network, a metabolite-metabolite network, and a gene-metabolite network to simultaneously prioritize candidate disease-associated metabolites and gene expressions could further utilize gene-metabolite interactions that are not used when prioritizing them separately. However, the number of metabolites is usually 100 times fewer than that of genes. Without accounting for this imbalance issue, we cannot effectively use gene-metabolite interactions when simultaneously prioritizing disease-associated metabolites and genes.

RESULTS

Here, we developed a Multi-omics Network Enhancement Prioritization (MultiNEP) framework with a weighting scheme to reweight contributions of different sub-networks in a multi-omics network to effectively prioritize candidate disease-associated metabolites and genes simultaneously. In simulation studies, MultiNEP outperforms competing methods that do not address network imbalances and identifies more true signal genes and metabolites simultaneously when we down-weight relative contributions of the gene-gene network and up-weight that of the metabolite-metabolite network to the gene-metabolite network. Applications to two human cancer cohorts show that MultiNEP prioritizes more cancer-related genes by effectively using both within- and between-omics interactions after handling network imbalance.

AVAILABILITY AND IMPLEMENTATION

The developed MultiNEP framework is implemented in an R package and available at: https://github.com/Karenxzr/MultiNep.

Genomic Landscape Alterations in Primary Tumor and Matched Lymph Node Metastasis in Hormone-Naïve Prostate Cancer Patients

Background: Prostate cancer (PCa) is a disease with a wide range of clinical manifestations. Up to the present date, the genetic understanding of patients with favorable or unfavorable prognosis is gaining interest for giving the appropriate tailored treatment. We aimed to investigate genetic changes associated with lymph node metastasis in a cohort of hormone-naïve Pca patients. Methods: We retrospectively analyzed data from 470 patients who underwent surgery for PCa between 2010 and 2020 at the Department of Urology, University of Catania. Inclusion criteria were patients with lymph node metastasis and patients with PCa with extra capsular extension (pT3) and negative lymph node metastasis. The final cohort consisted of 17 different patients (11 PCa with lymph node metastasis and 6 PCa without lymph node metastasis). Through the cBioPortal online tool, we analyzed gene alterations and their correlations with clinical factors. Results: A total of 688 intronic, synonym and nonsynonym mutations were sequenced. The gene with the most sequenced mutations was ERBB4 (83 mutations, 12% of 688 total), while the ones with the lower percentage of mutations were AKT1, FGFR2 and MLH1 (1 mutation alone, 0.14%). Conclusion: In the present study we found mostly concordance concerning the ERBB4 mutation between both primary PCa samples and matched lymph node metastasis, underlining that the identification of alterations in the primary tumor is extremely important for cancer prognosis prediction.

Cyclocreatine Suppresses Creatine Metabolism and Impairs Prostate Cancer Progression

Prostate cancer is the second most common cause of cancer mortality in men worldwide. Applying a novel genetically engineered mouse model (GEMM) of aggressive prostate cancer driven by deficiency of the tumor suppressors PTEN and Sprouty2 (SPRY2), we identified enhanced creatine metabolism as a central component of progressive disease. Creatine treatment was associated with enhanced cellular basal respiration in vitro and increased tumor cell proliferation in vivo. Stable isotope tracing revealed that intracellular levels of creatine in prostate cancer cells are predominantly dictated by exogenous availability rather than by de novo synthesis from arginine. Genetic silencing of creatine transporter SLC6A8 depleted intracellular creatine levels and reduced the colony-forming capacity of human prostate cancer cells. Accordingly, in vitro treatment of prostate cancer cells with cyclocreatine, a creatine analog, dramatically reduced intracellular levels of creatine and its derivatives phosphocreatine and creatinine and suppressed proliferation. Supplementation with cyclocreatine impaired cancer progression in the PTEN- and SPRY2-deficient prostate cancer GEMMs and in a xenograft liver metastasis model. Collectively, these results identify a metabolic vulnerability in prostate cancer and demonstrate a rational therapeutic strategy to exploit this vulnerability to impede tumor progression.

SIGNIFICANCE

Enhanced creatine uptake drives prostate cancer progression and confers a metabolic vulnerability to treatment with the creatine analog cyclocreatine.

The Extracellular Matrix Stiffening: A Trigger of Prostate Cancer Progression and Castration Resistance?

Despite advancements made in diagnosis and treatment, prostate cancer remains the second most diagnosed cancer among men worldwide in 2020, and the first in North America and Europe. Patients with localized disease usually respond well to first-line treatments, however, up to 30% develop castration-resistant prostate cancer (CRPC), which is often metastatic, making this stage of the disease incurable and ultimately fatal. Over the last years, interest has grown into the extracellular matrix (ECM) stiffening as an important mediator of diseases, including cancers. While this process is increasingly well-characterized in breast cancer, a similar in-depth look at ECM stiffening remains lacking for prostate cancer. In this review, we scrutinize the current state of literature regarding ECM stiffening in prostate cancer and its potential association with disease progression and castration resistance.

Autocrine Canonical Wnt Signaling Primes Noncanonical Signaling through ROR1 in Metastatic Castration-Resistant Prostate Cancer

Wnt signaling driven by genomic alterations in genes including APC and CTNNB, which encodes β-catenin, have been implicated in prostate cancer development and progression to metastatic castration-resistant prostate cancer (mCRPC). However, nongenomic drivers and downstream effectors of Wnt signaling in prostate cancer and the therapeutic potential of targeting this pathway in prostate cancer have not been fully established. Here we analyzed Wnt/β-catenin signaling in prostate cancer and identified effectors distinct from those found in other tissues, including aryl hydrocarbon receptor and RUNX1, which are linked to stem cell maintenance, and ROR1, a noncanonical Wnt5a coreceptor. Wnt/β-catenin signaling-mediated increases in ROR1 enhanced noncanonical responses to Wnt5a. Regarding upstream drivers, APC genomic loss, but not its epigenetic downregulation commonly observed in prostate cancer, was strongly associated with Wnt/β-catenin pathway activation in clinical samples. Tumor cell upregulation of the Wnt transporter Wntless (WLS) was strongly associated with Wnt/β-catenin pathway activity in primary prostate cancer but also associated with both canonical and noncanonical Wnt signaling in mCRPC. IHC confirmed tumor cell WLS expression in primary prostate cancer and mCRPC, and patient-derived prostate cancer xenografts expressing WLS were responsive to treatment with Wnt synthesis inhibitor ETC-1922159. These findings reveal that Wnt/β-catenin signaling in prostate cancer drives stem cell maintenance and invasion and primes for noncanonical Wnt signaling through ROR1. They further show that autocrine Wnt production is a nongenomic driver of canonical and noncanonical Wnt signaling in prostate cancer, which can be targeted with Wnt synthesis inhibitors to suppress tumor growth.

SIGNIFICANCE

This work provides fundamental insights into Wnt signaling and prostate cancer cell biology and indicates that a subset of prostate cancer driven by autocrine Wnt signaling is sensitive to Wnt synthesis inhibitors.

MicroRNA‑20a promotes non‑small cell lung cancer proliferation by upregulating PD‑L1 by targeting PTEN

Non-small cell lung cancer (NSCLC) remains one of the most common malignant tumors worldwide. The aim of the present study was to investigate the possibility of microRNA-20a (miR-20a) as a biomarker and therapeutic target for the diagnosis and treatment of NSCLC. Bioinformatics prediction, together with functional validation, confirmed miR-20a bound to programmed death ligand-1 (PD-L1) 3′-untranslated region to upregulate PD-L1 expression. Both miR-20a and PD-L1 could promote the proliferation of NSCLC cells. The expression level of PD-L1 was controlled by PTEN; however, further upstream regulation of PD-L1 expression was largely unknown. The present study showed that miR-20a could not restore the inhibition of PD-L1 expression levels by PTEN. Knockdown of PTEN expression upregulated the expression level of PD-L1 and promoted the proliferation of NSCLC cells. PTEN negatively regulated the Wnt/β-catenin signaling pathway by inhibiting β-catenin and Cyclin D1. Interestingly, PTEN could reverse miR-20a-mediated proliferation of NSCLC cells and the inhibitory effect was similar to that of XAV-939. miR-20a promotes the proliferation of NSCLC cells by inhibiting the expression level of PTEN and upregulating the expression level of PD-L1. It is suggested that miR-20a could be used as a biomarker and therapeutic target for the treatment of NSCLC.

Exploring the Wnt Pathway as a Therapeutic Target for Prostate Cancer

Aberrant activation of the Wnt pathway is emerging as a frequent event during prostate cancer that can facilitate tumor formation, progression, and therapeutic resistance. Recent discoveries indicate that targeting the Wnt pathway to treat prostate cancer may be efficacious. However, the functional consequence of activating the Wnt pathway during the different stages of prostate cancer progression remains unclear. Preclinical work investigating the efficacy of targeting Wnt signaling for the treatment of prostate cancer, both in primary and metastatic lesions, and improving our molecular understanding of treatment responses is crucial to identifying effective treatment strategies and biomarkers that help guide treatment decisions and improve patient care. In this review, we outline the type of genetic alterations that lead to activated Wnt signaling in prostate cancer, highlight the range of laboratory models used to study the role of Wnt genetic drivers in prostate cancer, and discuss new mechanistic insights into how the Wnt cascade facilitates prostate cancer growth, metastasis, and drug resistance.

miR-381 Reverses Multidrug Resistance by Negative Regulation of the CTNNB1/ABCB1 Pathway in HepG2/Dox Cells, and the Diagnostic and Prognostic Values of CTNNB1/ABCB1 Are Identified in Patients with LIHC

Multidrug resistance (MDR) is the biggest challenge in cancer therapy. In this study, we explored the molecular mechanism of MDR in human liver cancer and explored the related diagnostic and prognostic values of the targeted genes in patients with hepatocellular carcinoma. We constructed a multidrug-resistant liver cancer cell line, HepG2/Dox, using the parental subline HepG2. The (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) (MTT) assay was used to test the viability of the liver cancer cells. Western blotting was performed to test the expression of ABCB1, β-catenin, and β-actin. Luciferase assays were performed to confirm the relationship between miR-381 and its target genes. The diagnostic and prognostic values of target genes were analyzed using publicly available data from The Cancer Genome Atlas. The Mann-Whitney U test and logistic regression were performed to evaluate the association between ABCB1 or CTNNB1 expression and clinical features in patients with liver hepatocellular carcinoma (LIHC). Finally, Kaplan-Meier and Cox regression analyses were performed to test the effect of ABCB1 or CTNNB1 expression on the overall survival of patients with LIHC. ABCB1 expression was upregulated in HepG2/Dox cells. ABCB1 was found to be a direct target of hsa-miR-381 and was negatively regulated by has-miR-381. Moreover, hsa-miR-381 directly targeted the CTNNB1 3' UTR and decreased the luciferase activity of CTNNB1. Transfection with miR-183 partially reversed chemotherapeutic drug resistance by downregulating the expression of ABCB1 and CTNNB1 in HepG2/Dox cells. Spearman's analysis results showed that CTNNB1 and ABCB1 were positively correlated in patients with liver cancer, and increased CTNNB1 and ABCB1 expression occurred in patients with liver cancer. High expression of ABCB1 and CTNNB1 indicated poor prognosis in patients with liver cancer; however, neither ABCB1 nor CTNNB1 expression was an independent diagnostic factor in patients with LIHC. Overexpression of hsa-miR-381 partially reversed the MDR of HepG2 cells by directly targeting and negatively regulating the expression of CTTNB1 and ABCB1. Moreover, high expression of ABCB1 or CTNNB1 indicated poor prognosis in patients with liver cancer.

Characterization of a castrate-resistant prostate cancer xenograft derived from a patient of West African ancestry

BACKGROUND

Prostate cancer is a clinically and molecularly heterogeneous disease, with highest incidence and mortality among men of African ancestry. To date, prostate cancer patient-derived xenograft (PCPDX) models to study this disease have been difficult to establish because of limited specimen availability and poor uptake rates in immunodeficient mice. Ancestrally diverse PCPDXs are even more rare, and only six PCPDXs from self-identified African American patients from one institution were recently made available.

METHODS

In the present study, we established a PCPDX from prostate cancer tissue from a patient of estimated 90% West African ancestry with metastatic castration resistant disease, and characterized this model's pathology, karyotype, hotspot mutations, copy number, gene fusions, gene expression, growth rate in normal and castrated mice, therapeutic response, and experimental metastasis.

RESULTS

This PCPDX has a mutation in TP53 and loss of PTEN and RB1. We have documented a 100% take rate in mice after thawing the PCPDX tumor from frozen stock. The PCPDX is castrate- and docetaxel-resistant and cisplatin-sensitive, and has gene expression patterns associated with such drug responses. After tail vein injection, the PCPDX tumor cells can colonize the lungs of mice.

CONCLUSION

This PCPDX, along with others that are established and characterized, will be useful pre-clinically for studying the heterogeneity of prostate cancer biology and testing new therapeutics in models expected to be reflective of the clinical setting.

Melatonin restores osteoporosis-impaired osteogenic potential of bone marrow mesenchymal stem cells and alleviates bone loss through the HGF/PTEN/Wnt/β-catenin axis

Background:

Previous studies reported that melatonin exerts its effect on mesenchymal stem cell (MSC) survival and differentiation into osteogenic and adipogenic lineage. In the current study we aimed to explore the effect of melatonin on osteoporosis and relevant mechanisms.

Methods:

Real-time qualitative polymerase chain reaction (RT-qPCR) and Western blot analysis were conducted to determine expression of HGF, PTEN, and osteoblast differentiation-related genes in ovariectomy (OVX)-induced osteoporosis mice and the isolated bone marrow MSCs (BMSCs). Pre-conditioning with melatonin (1 μmol/l, 10 μmol/l and 100 μmol/l) was carried out in OVX mice BMSCs. Bone microstructure was analyzed using micro-computed tomography and the contents of alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase 5b (TRAP5b) were detected by enzyme-linked immunosorbent assay in serum. BMSC proliferation was measured by cell-counting kit (CCK)-8 assay. Alizarin red S (ARS) staining and ALP activity assay were performed to assess BMSC mineralization and calcification. The activity of the Wnt/β-catenin pathway was evaluated by dual-luciferase reporter assay.

Results:

Melatonin prevented bone loss in OVX mice. Melatonin increased ALP expression and reduced TRAP5b expression. HGF and β-catenin were downregulated, while PTEN was upregulated in the femur of OVX mice. Melatonin elevated HGF expression and then stimulated BMSC proliferation and osteogenic differentiation. Additionally, HGF diminished the expression of PTEN, resulting in activated Wnt/β-catenin pathway both in vitro and in vivo. Furthermore, melatonin was shown to ameliorate osteoporosis in OVX mice via the HGF/PTEN/Wnt/β-catenin axis.

Conclusion:

Melatonin could potentially enhance osteogenic differentiation of BMSCs and retard bone loss through the HGF/PTEN/Wnt/β-catenin axis.

CRISPR screening identifies CDK12 as a conservative vulnerability of prostate cancer

Androgen receptor (AR) signaling inhibitors provide limited survival benefits to patients with prostate cancer (PCa), and worse, few feasible genomic lesions restrict targeted treatment to PCa. Thus, a better understanding of the critical dependencies of PCa may enable more feasible therapeutic approaches to the dilemma. We performed a kinome-scale CRISPR/Cas9 screen and identified cyclin-dependent kinase 12 (CDK12) as being conservatively required for PCa cell survival. Suppression of CDK12 by the covalent inhibitor THZ531 led to an obvious anti-PCa effect. Mechanistically, THZ531 downregulated AR signaling and preferentially repressed a distinct class of CDK12 inhibition-sensitive transcripts (CDK12-ISTs), including prostate lineage-specific genes, and contributed to cellular survival processes. Integration of the super-enhancer (SE) landscape and CDK12-ISTs indicated a group of potential PCa oncogenes, further conferring the sensitivity of PCa cells to CDK12 inhibition. Importantly, THZ531 strikingly synergized with multiple AR antagonists. The synergistic effect may be driven by attenuated H3K27ac signaling on AR targets and an intensive SE-associated apoptosis pathway. In conclusion, we highlight the validity of CDK12 as a druggable target in PCa. The synergy of THZ531 and AR antagonists suggests a potential combination therapy for PCa.

Recent Insights on Genetic Testing in Primary Prostate Cancer

Prostate cancer (PCa) is one of the most common cancers in developed countries. The results of large trials indicate that the proportion of PCa attributable to hereditary factors is as high as 15%, highlighting the importance of genetic testing. Despite improved understanding of the prevalence of pathogenic variants among men with PCa, it remains unclear which men will most benefit from genetic testing. In this review, we summarize recent evidence on genetic testing in primary PCa and its impact on routine clinical practice. We outline current guideline recommendations on genetic testing, most importantly, for mutations in BRCA1/2, MMR, CHEK2, PALB2, and HOXB13 genes, as well as various single nucleotide polymorphisms associated with an increased risk of developing PCa. The implementation of genetic testing in clinical practice, especially in young patients with aggressive tumors or those with positive family history, represents a new challenge for the coming years and will identify men with pathogenic variants who may benefit from early screening/intervention and specific therapeutic options.

SMARCC2 combined with c‑Myc inhibits the migration and invasion of glioma cells via modulation of the Wnt/β‑catenin signaling pathway

Glioma is the most common type of central nervous system tumor. SWItch/sucrose non-fermentable (SWI/SNF) is a tumor suppressor that serves an important role in epithelial-mesenchymal transition (EMT). The present study aimed to identify key molecules involved in the EMT process. SWI/SNF related, matrix associated, actin dependent regulator of chromatin subfamily c member 2 (SMARCC2) is mutated in and its expression is low in multiple types of cancer. SMARCC2 is the core subunit of the chromatin-remodeling complex, SWI/SNF. Relative mRNA SMARCC2 expression levels in human glioma tissue were analyzed via reverse transcription-quantitative PCR, whereas the protein expression levels were determined via immunohistochemistry staining. SMARCC2 expression was knocked down in glioma cells using small interfering RNA (si) and overexpressed by infection with adenovirus vectors carrying SMARCC2 cDNA. Wound healing and Transwell assays were performed to assess cell migration and invasion, respectively. Subsequently, immunofluorescence and western blotting were performed to analyze the expression levels of the oncogene c-Myc, which is associated with SMARCC2. SMARCC2 combines with C-MYC to downregulate its expression. Consistent with the results of the bioinformatics analysis, which revealed that the upregulated expression levels of SMARCC2 were associated with a more favorable prognosis in patients with glioma, the mRNA and protein expression levels of SMARCC2 were significantly upregulated in low-grade glioma tissues compared with high-grade glioma tissues. The results of the wound healing assay demonstrated that cell migration was significantly increased in the siSMARCC2-1/3 groups compared with the negative control (NC) group. By contrast, the migratory ability of cells was significantly reduced following transduction with adenovirus overexpressing SMARCC2, which upregulated the expression of SMARCC2, compared with the lentiviral vector-non-specific control (LVS-NC) group. The Transwell assay results further showed that SMARCC2 overexpression significantly inhibited the migratory and invasive abilities of U87MG and LN229 cells compared with the LVS-NC group. Co-immunoprecipitation assays were subsequently conducted to validate the binding of SMARCC2 and c-Myc; the results demonstrated that the expression of c-Myc was downregulated in adenovirus-transfected cells compared with LVS-NC-transfected cells. The results of the western blotting experiments demonstrated that the expression levels of N-cadherin, vimentin, snail family transcriptional repressor 1 and β-catenin were notably downregulated, whereas the expression levels of T-cadherin were markedly upregulated in cell lines stably overexpressing SMARCC2 compared with the LVS-NC group. In conclusion, the results of the present study suggested that SMARCC2 may inhibit Wnt/β-catenin signaling by regulating c-Myc expression in glioma. SMARCC2 regulates the EMT status of the glioblastoma cell line by mediating the expression of the oncogene C-MYC to inhibit its migration and invasion ability. Thus, SMARCC2 may function as a tumor suppressor or oncogene by regulating associated oncogenes or tumor suppressor genes.

Direct interaction of β-catenin with nuclear ESM1 supports stemness of metastatic prostate cancer

Wnt/β-catenin signaling is frequently activated in advanced prostate cancer and contributes to therapy resistance and metastasis. However, activating mutations in the Wnt/β-catenin pathway are not common in prostate cancer, suggesting alternative regulations may exist. Here, we report that the expression of endothelial cell-specific molecule 1 (ESM1), a secretory proteoglycan, is positively associated with prostate cancer stemness and progression by promoting Wnt/β-catenin signaling. Elevated ESM1 expression correlates with poor overall survival and metastasis. Accumulation of nuclear ESM1, instead of cytosolic or secretory ESM1, supports prostate cancer stemness by interacting with the ARM domain of β-catenin to stabilize β-catenin-TCF4 complex and facilitate the transactivation of Wnt/β-catenin signaling targets. Accordingly, activated β-catenin in turn mediates the nuclear entry of ESM1. Our results establish the significance of mislocalized ESM1 in driving metastasis in prostate cancer by coordinating the Wnt/β-catenin pathway, with implications for its potential use as a diagnostic or prognostic biomarker and as a candidate therapeutic target in prostate cancer.

LINC00861 inhibits the progression of cervical cancer&nbsp;cells by functioning as a ceRNA for miR‑513b‑5p and&nbsp;regulating the PTEN/AKT/mTOR signaling pathway

Long non‑coding RNAs (lncRNAs) have been discovered to serve important roles in a variety of types of cancer, including cervical cancer. The low expression of lncRNA long intergenic non‑protein coding RNA 861 (LINC00861) is related to poor prognosis in ovarian cancer. However, the effects and underlying mechanisms of LINC00861 in cervical cancer remain largely unknown. The present study aimed to examine the role of LINC00861 in the development and progression of ovarian cancer and its underlying mechanisms. The expression levels of LINC00861 and microRNA (miR)‑513b‑5p were analyzed using reverse transcription‑quantitative PCR analysis. Cell proliferation, migration and invasion were measured by using Cell Counting Kit‑8, colony formation, wound healing and Transwell assays, respectively. A luciferase assay was used to determine whether miR‑513b‑5p targeted LINC00861 and PTEN. The expression of protein was measured by using western blot assay. The results of the present study discovered that LINC00861 expression levels were significantly downregulated in cervical cancer tissues and CaSki and ME‑180 cell lines. Downregulated LINC00861 expression levels were identified to be associated with an advanced‑stage, lymph node metastasis and the poor survival of patients with cervical cancer. Gene Set Enrichment Analysis revealed that the PI3K/AKT/mTOR signaling pathway was significantly enriched in cervical tumors expressing low expression levels of LINC00861 compared with tumors expressing high levels of LINC00861. The overexpression of LINC00861 reduced cervical cancer cell proliferation, migration, invasion and epithelial‑mesenchymal transition (EMT) processes, upregulated PTEN protein expression levels and downregulated phosphorylated (p)‑AKT and p‑mTOR protein expression levels. The regulatory relationship between LINC00861, microRNA (miR)‑513b‑5p and PTEN was validated using a dual luciferase reporter gene assay. PTEN expression levels were significantly downregulated in the miR‑513b‑5p mimic group and significantly upregulated in the miR‑513b‑5p inhibitor group compared with the mimic NC and inhibitor NC in both cell lines. Furthermore, LINC00861 was suggested to serve as a competing endogenous RNA by sponging miR‑513b‑5p and consequently upregulating the expression levels of PTEN in cervical cancer cells. The expression of PTEN, the phosphorylation of Akt and mTOR and and the EMT phenotype were rescued following co‑transfection with LINC00861 and miR‑513b‑5p mimics. In conclusion, the findings of the present study indicated that the LINC00861/miR‑513b‑5p axis may inhibit the progression of cervical cancer cells through the PTEN/AKT/mTOR signaling pathway to suppress the EMT process.

Senescence and castration resistance in prostate cancer: A review of experimental evidence and clinical implications

The development of Castration-Resistant Prostate Cancer (CRPC) remains a major challenge in the treatment of this disease. While Androgen Deprivation Therapy (ADT) can result in tumor shrinkage, a primary response of Prostate Cancer (PCa) cells to ADT is a senescent growth arrest. As a response to cancer therapies, senescence has often been considered as a beneficial outcome due to its association with stable growth abrogation, as well as the potential for immune system activation via the Senescence-Associated Secretory Phenotype (SASP). However, there is increasing evidence that not only can senescent cells regain proliferative capacity, but that senescence contributes to deleterious effects of cancer chemotherapy, including disease recurrence. Notably, the preponderance of work investigating the consequences of therapy-induced senescence on tumor progression has been performed in non-PCa models. Here, we summarize the evidence that ADT promotes a senescent response in PCa and postulate mechanisms by which senescence may contribute to the development of castration-resistance. Primarily, we suggest that ADT-induced senescence may support CRPC development via escape from senescence, by cell autonomous-reprogramming, and by the formation of a pro-tumorigenic SASP. However, due to the scarcity of direct evidence from PCa models, the consequences of ADT-induced senescence outlined here remain speculative until the relationship between senescence and CRPC can be experimentally defined.

Identification of Critical Pathways and Hub Genes in LanCL1-Overexpressed Prostate Cancer Cells

Background

Prostate cancer is one of the most common malignancies in urology, especially in developed countries. Our previous studies showed that Lanthionine synthase C-like protein 1 (LanCL1) can promote the proliferation of prostate cancer cells and protect cells from oxidative stress. Also, LanCL1 protects cells by inhibiting the JNK signaling pathway after H₂O₂ treatment.

Materials and Methods

In our study, we analyzed the data of RNA-seq to identify the DEGs after LanCL1 overexpression. We performed a functional enrichment analysis with gene set enrichment analysis (GSEA) and a database for annotation, visualization, and integrated discovery (DAVID). We also identified the critical hub gene correlated with disease prognosis by Cox regression analysis.

Results

A total of 8928 DEGs were identified. Through the analysis of GO and KEGG, we found that DEGs are significantly enriched in categories related to metabolism, cancer-related signaling pathways, and inflammation. The top 15 hub genes were then identified and ranked by degree from the protein–protein interaction network. Survival analysis showed 4 hub genes related to disease prognosis and ICAM1 expression is an independent risk factor for the prognosis.

Conclusion

Our results suggest the critical genes and pathways that might play key roles after LanCL1 overexpression in prostate cancer. We also provide candidate gene targets that might play important roles in prostate cancer development.

The PI3K-AKT-mTOR Pathway and Prostate Cancer: At the Crossroads of AR, MAPK, and WNT Signaling

Oncogenic activation of the phosphatidylinositol-3-kinase (PI3K), protein kinase B (PKB/AKT), and mammalian target of rapamycin (mTOR) pathway is a frequent event in prostate cancer that facilitates tumor formation, disease progression and therapeutic resistance. Recent discoveries indicate that the complex crosstalk between the PI3K-AKT-mTOR pathway and multiple interacting cell signaling cascades can further promote prostate cancer progression and influence the sensitivity of prostate cancer cells to PI3K-AKT-mTOR-targeted therapies being explored in the clinic, as well as standard treatment approaches such as androgen-deprivation therapy (ADT). However, the full extent of the PI3K-AKT-mTOR signaling network during prostate tumorigenesis, invasive progression and disease recurrence remains to be determined. In this review, we outline the emerging diversity of the genetic alterations that lead to activated PI3K-AKT-mTOR signaling in prostate cancer, and discuss new mechanistic insights into the interplay between the PI3K-AKT-mTOR pathway and several key interacting oncogenic signaling cascades that can cooperate to facilitate prostate cancer growth and drug-resistance, specifically the androgen receptor (AR), mitogen-activated protein kinase (MAPK), and WNT signaling cascades. Ultimately, deepening our understanding of the broader PI3K-AKT-mTOR signaling network is crucial to aid patient stratification for PI3K-AKT-mTOR pathway-directed therapies, and to discover new therapeutic approaches for prostate cancer that improve patient outcome.