proBDNF/p75NTR promotes rheumatoid arthritis and inflammatory response by activating proinflammatory cytokines.

P75 pan-neurotrophin receptor (p75NTR) is an important receptor for the role of neurotrophins in survival and death of neurons during development and after nerve injury. Our previous research found that the precursor of brain-derived neurotrophic factor (proBDNF) regulates pain as an inflammatory mediator. The current understanding of the role of proBDNF/p75NTR signaling pathway in inflammatory arthritis pain and rheumatoid arthritis (RA) is unclear. We recruited 20 RA patients, 20 healthy donors (HDs), and 10 osteoarthritis (OA) patients. Hematoxylin and eosin (H&E) staining and immunohistochemistry (IHC) of proBDNF and p75NTR in synovial membrane were performed and evaluated. We next examined the mRNA and protein expression of proBDNF/p75NTR signaling pathway in peripheral blood mononuclear cells (PBMCs) and synovial tissue. ELISA and flow cytometry were assessed between the blood of RA patients and HD. To induce RA, collagen-induced arthritis (CIA) were induced in mice. We found over-synovitis of RA synovial membrane compared to OA controls in histologic sections. P75NTR and sortilin mRNA, and proBDNF protein level were significantly increased in PBMCs of RA patients compared with the HD. Consistently, ELISA showed that p75NTR, sortilin, tumor necrosis factor α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and interleukin-10 (IL-10) levels in the serum of RA patients were increased compared with HD and p75NTR, sortilin were positively correlated with Disease Activity Score in 28 joints (DAS28). In addition, using flow cytometry we showed that the increased levels of proBDNF and p75NTR characterized in CD4+ and CD8+ T cells of RA patients were subsequently reversed with methotrexate (MTX) treatment. Furthermore, we found pathological changes, inflammatory pain, upregulation of the mRNA and protein expression of proBDNF/p75NTR signaling pathway, and upregulation of inflammatory cytokines in spinal cord using a well-established CIA mouse model. We showed intravenous treatment of recombinant p75ECD-Fc that biologically blocked all inflammatory responses and relieved inflammatory pain of animals with CIA. Our findings showed the involvement of proBDNF/p75NTR pathway in the RA inflammatory response and how blocking it with p75ECD-Fc may be a promising therapeutic treatment for RA.

Relationship between a 7-mRNA signature of the pancreatic adenocarcinoma microenvironment and patient prognosis (a STROBE-compliant article).

The potential association between the prognosis of the pancreatic adenocarcinoma (PAAD) and its microenvironment is unclear. This study aims to construct a prognostic index (PI) model of the PAAD microenvironment to predict PAAD patient survival outcomes.The mRNA sequencing and the clinical parameters data were obtained from The Cancer Genome Atlas. Immune and stromal scores were computed using the expression data algorithm to capture infiltration of immune and stromal cells in the PAAD tissue, where patients were categorized as high and low score groups according to these scores. Differentially expressed genes were identified using the R package LIMMA. Univariate and multivariate Cox regression analysis were conducted to select candidate survival-correlated gene signatures from the tumor microenvironment for constructing a model. The Kaplan-Meier method was used to access overall survival of the primary and validation cohorts. The immunological features of the PI model was explored using the Tumor Immune Estimation Resource (TIMER) database. Bioinformatic analyses were conducted based on the DAVID database.A total of 1266 overlapping differentially expressed genes and 49 prognosis-associated genes were identified. A 7-mRNA signature (GBP5, BICC1, SLC7A14, CYSLTR1, P2RY6, VENTX, and RAB39B) was screened for the construction of a PI model (area under the curve = 0.791). In both the primary and validation cohorts, Kaplan Meier analysis revealed that the overall survival of the high-risk group was significantly worse compared to the low-risk group (P < .0001, P = .0028 respectively). The TIMER database described that the 7 signature genes were correlated with immune infiltrating cells and tumor purity. Bioinformatic analyses revealed that these prognosis-associated genes were significantly enriched during inflammation, the defense response, would response, calcium ion transport, and plasma membrane part.A list of the prognosis-correlated genes was generated based on the PAAD microenvironment. A 7-mRNA PI model may be used for predicting the prognosis of PAAD patients.

miR-145 Inhibits Th9 Cell Differentiation by Suppressing Activation of the PI3K/Akt/mTOR/p70S6K/HIF-1α Pathway in Malignant Ascites from Liver Cancer.

PURPOSE: Our previous experiments confirmed that T helper type 9 (Th9) cells were involved in the occurrence and development of malignant ascites caused by liver cancer. The current study investigated the mechanism underlying microRNA (miR-145)-mediated inhibition of Th9 cells in an malignant ascites model with liver cancer. MATERIALS AND METHODS: CD4+ T cells were induced to differentiate Th9 cells after transfection with miR-145 mimics or negative control. A malignant ascites mouse model was transfected with miR-145agomir or negative control. Th9 cells were detected by flow cytometry. Enzyme-linked immunosorbent assay was applied to detect the interleukin 9 (IL-9) cytokine and hypoxia-inducible factor 1 alpha (HIF-1α). RT-PCR was used to detect the expression of miR-145 and phosphatidylinositol-3-kinase/Akt/mammalian target of rapamycin/p70 ribosomal protein S6 kinase/HIF-1α (PI3K/Akt/mTOR/p70S6K/HIF-1α) mRNA. Western blotting and immunofluorescence were performed to detect the expression of PI3K/Akt/mTOR/p70S6K/HIF-1α-related proteins. RESULTS: In vitro experiments showed that miR-145 inhibited Th9 cell polarization, HIF-1α expression, and PI3K/Akt/mTOR/p70S6K pathway activation. In the malignant ascites mouse model, miR-145 also demonstrated inhibitory effects on Th9 cell differentiation through the PI3K/Akt/mTOR/p70S6K/HIF-1α pathway. CONCLUSION: miR-145 may inhibit Th9 cell differentiation through the PI3K/Akt/mTOR/p70S6K/HIF-1α pathway. These findings suggest a novel therapeutic target for malignant ascites from liver cancer.

High expression of RAB38 promotes malignant progression of pancreatic cancer.

Ras­Related Protein Rab­38 (RAB38), which belongs to the RAB family, is involved in the biogenesis of lysosome­related organelles and defense against certain microbial infections. However, the clinical significance and potential function of RAB38 in pancreatic adenocarcinoma remain unclear. In the present study, an immunohistochemical assay was performed to analyze the expression of RAB38 in pancreatic adenocarcinoma tumor specimens from 82 patients, and the clinicopathological characteristics and survival rate of these patients were further examined. To validate the role of RAB38 in tumors, the effect of RAB38 on tumor cell proliferation, migration and invasion was assessed by establishing RAB38 knockdown cell lines. Reverse transcription­quantitative polymerase chain reaction and western blotting were used to examine the expression levels of proteins associated with the cancer cell behavior. In addition, the inhibitory effect of RAB38 silencing on pancreatic cancer was examined in mice. The immunohistochemistry results revealed that RAB38 was upregulated and positively correlated with the grade of progression in pancreatic adenocarcinoma patients. Further investigation indicated that RAB38 downregulation significantly suppressed the proliferation, migration and invasive capacity of pancreatic cancer cells, as well as decreased the expression levels of Ki67, proliferating cell nuclear antigen, and matrix metalloproteinases 2 and 9. RAB38 silencing also inhibited the development of pancreatic cancer in vivo. Taken together, a high level of RAB38 was significantly associated with the malignant phenotypes of pancreatic cancer, suggesting that RAB38 may serve as a novel biomarker and a potential therapeutic target for pancreatic cancer.

Loss of the Tumor Suppressor HACE1 Contributes to Cancer Progression.

HACE1 belongs to the family of HECT domain-containing E3 ligases, which plays an important role in the occurrence, invasion and metastatic process in many human malignancies. HACE1 is a tumor suppressor gene that is reduced in most cancer tissues compared to adjacent normal tissue. The loss or knocking out of HACE1 leads to enhanced tumor growth, invasion, and metastasis; in contrast, the overexpression of HACE1 can inhibit the development of tumors. Hypermethylation reduces the expression of HACE1, thereby promoting tumor development. HACE1 can inhibit the development of inflammation or tumors via the ubiquitination pathway. Therefore, HACE1 may be a potential therapeutic target, providing new strategies for disease prevention and treatment.