Highlights d Lipid rafts of adipogenic progenitors accumulate around ciliary base upon stimuli d Lipid raft accumulation propagates adipogenic IR/IGF1R-Akt signaling upon stimuli d Ciliary elongation in APs suppresses lipid raft accumulation upon stimuli d Tchp À/À mice are resistant to obesity by high-fat diet and increased thermogenesis

Background: Pirfenidone (PFD), which is an antifibrotic agent used for treatment of idiopathic pulmonary fibrosis, induces G0/G1 cell cycle arrest in fibroblasts. We hypothesized that PFD-induced G0/G1 cell cycle arrest might be achieved in other types of cells, including cancer cells. Here we investigated the effects of PFD on the proliferation of pancreatic cancer cells (PCCs) in vitro. Method: Human skin fibroblasts ASF-4-1 cells and human prostate stromal cells (PrSC) were used as fibroblasts. PANC-1, MIA PaCa-2, and BxPC-3 cells were used as human PCCs. Cell cycle and apoptosis were analyzed using flow cytometer. Results: First, we confirmed that PFD suppressed cell proliferation of ASF-4-1 cells and PrSC and induced G0/G1 cell cycle arrest. Under these experimental conditions, PFD also suppressed cell proliferation and induced G0/G1 cell cycle arrest in all PCCs. In PFD-treated PCCs, expression of p21 was increased but that of CDK2 was not clearly decreased. Of note, PFD did not induce significant apoptosis among PCCs. Conclusions: These results demonstrated that the antifibrotic agent PFD might have antiproliferative effects on PCCs by inducing G0/G1 cell cycle arrest. This suggests that PFD may target not only fibroblasts but also PCCs in the tumor microenvironment of pancreatic cancer.

Prostate cancer (PCa) cells frequently invade the surrounding stroma, leading to heterogeneous formation of structural atypia. The surrounding stroma contains multiple functionally diverse populations of fibroblasts that trigger numerous changes in PCa cells including motility. Thus, we hypothesized that direct or indirect contact of PCa cells with fibroblasts determines an invasive phenotype in PCa cells. We investigated the effects of 10 different patient‐derived fibroblast lines on the three‐dimensional (3D) morphogenesis of PCa cells growing on a viscous substrate in vitro. When grown alone, all 10 patient‐derived fibroblast lines clumped on the viscous substrate, whereas the human androgen‐sensitive PCa cell line LNCaP did not. Cocultures of LNCaP cells with seven of the patient‐derived fibroblast lines (PrSC, pcPrF‐M5, pcPrF‐M7, pcPrF‐M23, pcPrF‐M24, pcPrF‐M28, and pcPrF‐M31) formed a thick fibroblast layer that resembled human prostate stromal structures. In contrast, cocultures of LNCaP cells with the remaining three fibroblast lines (NPF‐M13, pcPrF‐M10, and pcPrF‐M26) did not form a thick fibroblast layer. Of the seven fibroblast lines that caused thick layer formation, four patient‐derived fibroblast lines (PrSC, pcPrF‐M5, pcPrF‐M28, and pcPrF‐M31) induced an invasive phenotype in LNCaP cells with a cord‐like infiltrating growth pattern, whereas the other three fibroblast lines (pcPrF‐M7, pcPrF‐M23, and pcPrF‐M24) induced no or a very weak invasive phenotype. Using cell culture inserts, none of the four patient‐derived fibroblast lines that induced an invasive phenotype (PrSC, pcPrF‐M5, pcPrF‐M28, and pcPrF‐M31) affected CDH1 mRNA expression in LNCaP cells; yet, two patient‐derived fibroblast lines (pcPrF‐M5 and pcPrF‐M28) increased CDH2 mRNA expression in LNCaP cells, whereas the other two fibroblast lines (PrSC and pcPrF‐M31) did not. These results suggest that the existence of multiple functionally diverse populations of fibroblasts in PCa tissue may be responsible for the diversity in PCa cell invasion, leading to heterogeneous formation of structural atypia.

Following injury, skeletal muscle regenerates but fatty tissue accumulation is seen in aged muscle or muscular dystrophies. Fibro/adipogenic progenitors (FAPs) are key players in these events; however, the effect of primary cilia on FAPs remains unclear. Here, it is reported that genetic ablation of trichoplein (TCHP), a ciliary regulator, induces ciliary elongation on FAPs after injury, which promotes muscle regeneration while inhibiting adipogenesis. The defective adipogenic differentiation of FAPs is attributed to dysfunction of cilia-dependent lipid raft dynamics, which is critical for insulin/Akt signaling. It is also found that interleukin (IL) 13 is substantially produced by intramuscular FAPs, which are upregulated by ciliary elongation and contribute to regeneration. Mechanistically, upon injury, long cilia excessively activate the IL33/ST2/JNK axis to enhance IL13 production, facilitating myoblast proliferation and M2 macrophage polarization. The results indicate that FAPs organize the regenerative responses to skeletal muscle injury via cilia-mediated insulin/Akt and ST2/JNK signaling pathways.

Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of cancer-related death worldwide. The accuracy of a PDAC diagnosis based on endoscopic ultrasonography-guided fine-needle aspiration cytology can be strengthened by performing a rapid on-site evaluation (ROSE). However, ROSE can only be performed in a limited number of facilities, due to a relative lack of available resources or cytologists with sufficient training. Therefore, we developed the Mathematical Technology for Cytopathology (MTC) algorithm, which does not require teaching data or large-scale computing. We applied the MTC algorithm to support the cytological diagnosis of pancreatic cancer tissues, by converting medical images into structured data, which rendered them suitable for artificial intelligence (AI) analysis. Using this approach, we successfully clarified ambiguous cell boundaries by solving a reaction–diffusion system and quantitating the cell nucleus status. A diffusion coefficient (D) of 150 showed the highest accuracy (i.e., 74%), based on a univariate analysis. A multivariate analysis was performed using 120 combinations of evaluation indices, and the highest accuracies for each D value studied (50, 100, and 150) were all ≥70%. Thus, our findings indicate that MTC can help distinguish between adenocarcinoma and benign pancreatic tissues, and imply its potential for facilitating rapid progress in clinical diagnostic applications.