Ginsenoside Rg1 is a principal bioactive component of Panax ginseng and Panax notoginseng. Accumulating evidence indicates that ginsenoside Rg1 exerts pro-osteogenic effects; however, the underlying molecular mechanisms related to this function remain elusive. Our previous research demonstrates that leucine-rich repeat-containing G protein-coupled receptor 4 (LGR4) facilitates osteogenic differentiation in mesenchymal stem cells. Nevertheless, the potential association between LGR4 and ginsenoside Rg1 has not been elucidated. In the present study, we investigated the regulatory role of LGR4 in ginsenoside Rg1-induced osteogenic differentiation and delineated the underlying molecular mechanism. First, we validated the pro-osteogenic effect of ginsenoside Rg1 in mesenchymal stem cells. Subsequently, single-cell RNA sequencing was employed to evaluate the involvement of LGR4 in this process. Furthermore, a comprehensive set of experimental approaches was utilized to dissect the interaction between ginsenoside Rg1 and LGR4. Our data demonstrated that ginsenoside Rg1 significantly promoted osteogenic differentiation in mesenchymal stem cells and led to a marked increase in LGR4 and β-catenin. The pro-osteogenic effects of ginsenoside Rg1 were substantially abrogated by either LGR4 or β-catenin knockdown. Mechanistically, ginsenoside Rg1 directly binds to histone deacetylase 1 (HDAC1) and inhibits its acetylation modification. This interaction reduces HDAC1 level while increasing histone H4 lysine 16 acetylation levels, which in turn strengthens Lgr4 expression. Collectively, our findings reveal that ginsenoside Rg1 can activate the Wnt/β-catenin signaling pathway to stimulate osteogenic differentiation, which is mediated by LGR4 up-regulation via HDAC1 deacetylation and H4K16ac hyperacetylation. This study provides a novel mechanistic basis for the application of ginsenoside Rg1 in accelerating bone fracture healing.

Rhabdoid tumor is an ultra-rare and highly aggressive pediatric malignancy with a poor prognosis and limited therapeutic options. To identify novel immunotherapeutic targets, transcriptomic data from the Cancer Cell Line Encyclopedia were analyzed, and we found that two rhabdoid tumor cell lines exhibit high expression of prostate-specific membrane antigen (PSMA), with levels comparable to well-established PSMA-positive prostate cancer cell lines. PSMA expression in rhabdoid tumors was subsequently validated in cell lines and in a subset of primary clinical rhabdoid tumor specimens. While PSMA-directed therapies have primarily been explored in prostate cancer, we evaluated their potential in rhabdoid tumors by employing PSMA-directed chimeric antigen receptor (CAR) T cells. These CAR T cells demonstrated potent and antigen-specific cytotoxicity against PSMA-positive rhabdoid tumor cells in vitro. In addition, the in vivo efficacy was also assessed in xenograft mouse models of non-CNS tumors, where PSMA CAR T cell treatment resulted in significant tumor regression and robust accumulation of CAR T cells within the tumor microenvironment. Together, these findings establish PSMA as a promising surface antigen beyond prostate cancer and provide preclinical evidence supporting the development of PSMA-directed therapies for this highly lethal pediatric cancer.

Antiandrogen is part of the standard-of-care treatment option for metastatic prostate cancer. However, prostate cancers frequently relapse, and the underlying resistance mechanism remains incompletely understood. This study seeks to investigate whether long non-coding RNAs (lncRNAs) contribute to the resistance against the latest antiandrogen drug, darolutamide. Our RNA sequencing analysis revealed significant overexpression of LOC730101 in darolutamide-resistant cancer cells compared to the parental cells. Elevated LOC730101 levels were also observed in clinical samples of metastatic castration-resistant prostate cancer (CRPC) compared to primary prostate cancer samples. Silencing LOC730101 with siRNA significantly impaired the growth of darolutamide-resistant cells. Additional RNA sequencing analysis identified a set of genes regulated by LOC730101, including key players in the cell cycle regulatory pathway. We further demonstrated that LOC730101 promotes darolutamide resistance by competitively inhibiting microRNA miR-1-3p. Moreover, by Hi-C sequencing, we found that LOC730101 is located in a topologically associating domain (TAD) that undergoes specific gene induction in darolutamide-resistant cells. Collectively, our study demonstrates the crucial role of the lncRNA LOC730101 in darolutamide resistance and its potential as a target for overcoming antiandrogen resistance in CRPC.

Prostate cancer is one of the most prevalent cancers in men,and there is no cure when it advances to a late stage.Antiandrogens are routinely used in clinics for prostate cancer treatment,and darolutamide(Daro)is the latest FDA-approved antiandrogen drug.1 Despite its efficacy,potential drug resistance poses significant challenges in the clinical setting.This study seeks to uncover the molecular mechanisms behind darolutamide resistance and identify potential therapeutic targets to overcome this resistance.

PDF file - 73K, List of studied transcripts for enzymes involved in androgen synthesis and metabolism in prostate cancer

<p>XLS file - 91K, Linear correlation matrix resulting from the analysis of the log2-based mRNA levels in primary and metastatic PCas</p>

Primers used for PCR cloning and qPCR assays.

<p>XLS file - 18K, Log2-based expression (average and SD) of mRNA transcripts for AR and genes involved in androgen metabolism in normal prostate tissue, primary PCas and metastatic PCas</p>

<p>XLS file - 18K, Log2-based expression (average and SD) of mRNA transcripts for AR and genes involved in androgen metabolism in normal prostate tissue, primary PCas and metastatic PCas</p>

Description of additional methods and procedures used in the study. Also includes Supplemental References.

PDF file - 68K

Prostate cancer is the most commonly diagnosed noncutaneous cancer in American men. TDRD1, a germ cell-specific gene, is erroneously expressed in more than half of prostate tumors, but its role in prostate cancer development remains elusive. In this study, we identified a PRMT5-TDRD1 signaling axis that regulates the proliferation of prostate cancer cells. PRMT5 is a protein arginine methyltransferase essential for small nuclear ribonucleoprotein (snRNP) biogenesis. Methylation of Sm proteins by PRMT5 is a critical initiation step for assembling snRNPs in the cytoplasm, and the final snRNP assembly takes place in Cajal bodies in the nucleus. By mass spectrum analysis, we found that TDRD1 interacts with multiple subunits of the snRNP biogenesis machinery. In the cytoplasm, TDRD1 interacts with methylated Sm proteins in a PRMT5-dependent manner. In the nucleus, TDRD1 interacts with Coilin, the scaffold protein of Cajal bodies. Ablation of TDRD1 in prostate cancer cells disrupted the integrity of Cajal bodies, affected the snRNP biogenesis, and reduced cell proliferation. Taken together, this study represents the first characterization of TDRD1 functions in prostate cancer development and suggests TDRD1 as a potential therapeutic target for prostate cancer treatment.

Chimeric antigen receptor (CAR) T cell therapy represents a major breakthrough in cancer care since the approval of tisagenlecleucel by the Food and Drug Administration in 2017 for the treatment of pediatric and young adult patients with relapsed or refractory acute lymphocytic leukemia. As of April 2023, six CAR T cell therapies have been approved, demonstrating unprecedented efficacy in patients with B-cell malignancies and multiple myeloma. However, adverse events such as cytokine release syndrome and immune effector cell-associated neurotoxicity pose significant challenges to CAR T cell therapy. The severity of these adverse events correlates with the pretreatment tumor burden, where a higher tumor burden results in more severe consequences. This observation is supported by the application of CD19-targeted CAR T cell therapy in autoimmune diseases including systemic lupus erythematosus and antisynthetase syndrome. These results indicate that initiating CAR T cell therapy early at low tumor burden or using debulking strategy prior to CAR T cell infusion may reduce the severity of adverse events. In addition, CAR T cell therapy is expensive and has limited effectiveness against solid tumors. In this article, we review the critical steps that led to this groundbreaking therapy and explore ongoing efforts to overcome these challenges. With the promise of more effective and safer CAR T cell therapies in development, we are optimistic that a broader range of cancer patients will benefit from this revolutionary therapy in the foreseeable future.

Legends for Supplemental Figures S1-S12 and Supplemental Table S1.

Reciprocal gene set enrichment analysis reveals that SPOP F102C, F133V, and F133L mutants have similar effects on the PC transcriptome (S1); AR Activity Score of PC cells expressing wt or mutant SPOPs (S2); Effects of wt-SPOP and PC-associated SPOP mutants on mRNA expression of AR target genes in Abl PC cells (S3); The transcriptomic response induced by mt-SPOPs in PC cells enriches strongly for target genes of AR antagonists (S4); The impact of SPOP on AR protein levels in Abl cells is post-translational (S5); Wt-SPOP, but not its PC-associated mutants, suppresses AR protein levels in androgen-dependent PC cells (S6); The interaction between SPOP-wt and AR can occur even in the absence of SRC-3 protein (S7); Interaction and binding of SPOP-wt to AR is mediated by an SBC motif (a.a.646-a.a.651) located in the Hinge Region of the AR protein (S8); Endogenous SPOP interacts with and regulates the expression levels of the AR protein in PC cells (S9); The impact of SPOP on AR protein levels in 22Rv1 cells is post-translational (S10); Growth promoting effect of PC-associated SPOP mutants in the context of AR axis inhibition (S11); SPOP gene signature scores in human PC specimens correlate strongly with androgen receptor activity (S12).

XLS file - 134K, Results from one-way ANOVA comparing average expression of each transcript between groups (normal, primary PrCa and metastatic PrCa)

PDF file - 53K, Association of expression of transcripts involved in steroid synthesis and metabolism with AR transcriptional output in metastatic PCas

PDF file - 14K, Transcripts most-highly co-regulated with AKR1C3 in primary and metastatic PCas (top list: positive association; bottom list: negative association)

Schwann cell (SC) mitochondria are quickly emerging as an important regulator of myelin maintenance in the peripheral nervous system (PNS). However, the mechanisms underlying demyelination in the context of mitochondrial dysfunction in the PNS are incompletely understood. We recently showed that conditional ablation of the mitochondrial protein Prohibitin 1 (PHB1) in SCs causes a severe and fast progressing demyelinating peripheral neuropathy in mice, but the mechanism that causes failure of myelin maintenance remained unknown. Here, we report that mTORC1 and c-Jun are continuously activated in the absence of Phb1, likely as part of the SC response to mitochondrial damage. Moreover, we demonstrate that these pathways are involved in the demyelination process, and that inhibition of mTORC1 using rapamycin partially rescues the demyelinating pathology. Therefore, we propose that mTORC1 and c-Jun may play a critical role as executioners of demyelination in the context of perturbations to SC mitochondria.