Cancer-associated fibroblasts (CAFs) play a vital role in malignant transformation and progression of prostate cancer (PCa), and accumulating evidence suggests an enhancing effect of estrogens on PCa. The present study aimed to investigate the possible origin of prostate CAFs and the effects of estrogen receptors, G protein-coupled receptor 30 (GPR30) and estrogen receptor (ER)-α, on stromal cell activation. High expression of fibroblast activation protein (FAP), CD44, and nonmuscle myosin heavy chain B (SMemb) accompanied by low expression of smooth muscle differentiation markers was found in the stromal cells of PCa tissues and in cultured human prostate CAFs. Additionally, SMemb expression, which is coupled to cell phenotype switching and proliferation, was coexpressed with FAP, a marker of activated stromal cells, and with the stem cell marker CD44 in the stromal cells of PCa tissue. Prostate CAFs showed high GPR30 and low ERα expression. Moreover, GPR30 was coexpressed with FAP, CD44, and SMemb. Furthermore, the study demonstrated that the overexpression of GPR30 or the knockdown of ERα in prostate stromal cells induced the up-regulation of FAP, CD44, Smemb, and the down-regulation of smooth muscle markers. The conditioned medium from these cells promoted the proliferation and migration of LNCaP and PC3 PCa cells. GPR30 knockdown or ERα overexpression showed opposite effects. Finally, we present a novel mechanism whereby GPR30 limits ERα expression via inhibition of the cAMP/protein kinase A signaling pathway. These results suggest that stem-like cells within the stroma are a possible source of prostate CAFs and that the negative regulation of ERα expression by GPR30 is centrally involved in prostate stromal cell activation.

Prostate cancer (PCa) is a leading cause of cancer‑associated mortality in men; however, the factors that contribute to disease development have yet to be fully elucidated. Previous studies have suggested that prohibitin-2 (PHB2), which is a multifunctional protein that contributes to various cellular processes, is positively correlated with malignant progression of PCa; however, the molecular mechanisms underlying the effects of PHB2 on the enhancement of cell migration have not been identified. The present study induced overexpression and knockdown of PHB2 in PCa cell lines (PC3 and DU145) with the aim of examining the effects of PHB2 on PCa cell migration via wound healing assays. The results indicated that PHB2 overexpression promoted migration of both cell lines. AKT serine/threonine kinase 2 (AKT2), which interacts with PHB2, has been reported to participate in cell migration; therefore, the present study examined the effects PHB2 overexpression and knockdown on AKT2 in PCa cells. The present study demonstrated that overexpression of PHB2 reduced the expression of AKT2, whereas PHB2 knockdown increased AKT2 expression in both PCa cell lines. In addition, knockdown of PHB2 enhanced the protein stability of AKT2. Furthermore, AKT2 overexpression resulted in a significant decrease in migration, whereas AKT2 knockdown promoted migration of PC3 and DU145 PCa cells. The combined overexpression of PHB2 and AKT2 inhibited migration of both cell lines, thus suggesting that AKT2 overexpression abolished PHB2-induced migration. Mechanistically, the present study suggested that PHB2 may promote PCa cell migration by inhibiting the expression of AKT2. These results provide information regarding the role of PHB2 in PCa migration and malignancy.

Non-alcoholic fatty liver disease (NAFLD) has become one of the most common chronic liver diseases worldwide, and its prevalence is still growing rapidly. However, the efficient therapies for this liver disease are still limited. Mitochondrial dysfunction has been proven to be closely associated with NAFLD. The mitochondrial injury caused reactive oxygen species (ROS) production, and oxidative stress can aggravate the hepatic lipid accumulation, inflammation, and fibrosis. which contribute to the pathogenesis and progression of NAFLD. Therefore, pharmacological therapies that target mitochondria could be a promising way for the NAFLD intervention. Recently, natural products targeting mitochondria have been extensively studied and have shown promising pharmacological activity. In this review, the recent research progress on therapeutic effects of natural-product-derived compounds that target mitochondria and combat NAFLD was summarized, aiming to provide new potential therapeutic lead compounds and reference for the innovative drug development and clinical treatment of NAFLD.

Cancer‐associated fibroblasts (CAFs) can promote the development and metastasis of prostate cancer partly by mediating tumor‐associated inflammation. An increasing amount of studies have focused on the functional interactions between CAFs and immune cells in the tumor microenvironment (TME). We previously reported that G protein‐coupled receptor 30 (GPR30) was highly expressed in prostate CAFs and plays a crucial role in prostate stromal cell activation. However, the effect and underlying mechanism of GPR30 expression in prostate CAFs affecting the interaction between CAFs and tumor‐associated macrophages (TAMs) need further elucidation. Here, we found that, compared with CAF‐shControl, CAF‐shGPR30 inhibited macrophage migration through transwell migration assays, which should be attributed to the decreased expression of C‐X‐C motif chemokine ligand 12 (CXCL12). In addition, macrophages treated with a culture medium of CAF‐shGPR30 exhibited attenuated M2 polarization with downregulated M2‐like markers expression. Moreover, macrophages stimulated with a culture medium of CAF‐shGPR30 were less efficient in promoting activation of fibroblast cells and invasion of PCa cells. Finally, cocultured CAF‐shGPR30 and macrophages suppressed PCa cell invasion compared to cocultured CAF‐shControl and macrophages by decreasing interleukin‐6 (IL‐6) secretion, and this effect could be abrogated with rescue expression of IL‐6. Our results pinpoint the function of GPR30 in prostate CAFs on regulating the CAF‐TAM interaction in the TME and provide new insights into PCa therapies via regulating TME.

Senescent stromal cells support the development of prostate cancer and are considered potential therapeutic targets. This research evaluated the regulatory effects of ginsenoside Rg3 on the senescence of prostatic stromal cells pre-incubated in medium supplemented with 0.5% fetal bovine serum. The results revealed that ginsenoside Rg3 decreased the number of stromal cells positively stained with a senescent cell marker (senescence-associated β-galactosidase). Ginsenoside Rg3 also increased the viability of stromal cells and promoted cell cycle transition from G0/G1 to S phase, as well as inhibited the carcinoma-associated fibroblast-like phenotype in prostate stromal cells, through the up-regulation of smooth muscle cell markers SM22 and smooth muscle myosin heavy chain. Conditioned medium collected from stromal cells treated with ginsenoside Rg3 exhibited an attenuated effect on the promotion of prostate cancer cell migration compared with conditioned medium from stromal cells without Rg3 treatment. Down-regulation of interleukin 8 (IL-8) in a dose- and time-dependent manner was observed in ginsenoside Rg3-treated stromal cells, and over-expression or addition of IL-8 reversed the anti-senescence role of Rg3 in prostate stromal cells. Furthermore, ginsenoside Rg3 down-regulated IL-8 expression by decreasing the reactive oxygen species level in prostatic stromal cells and reducing the transcriptional activity of IL-8 promoter by damping the transcription factors C/EBP β and p65 binding to IL-8 promoter. Our research revealed that ginsenoside Rg3 was able to inhibit prostate stromal cell senescence by down-regulating IL-8 expression. The results suggest a potential value for ginsenoside Rg3 in prostate cancer treatment through the targeting of pro-carcinogenic senescent stromal cells.