Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease characterized by chronic non-specific inflammation of the interstitial lung and extensive deposition of collagen fibers leading to destruction of lung function. Studies have demonstrated that exposure to fine particulate matter (PM2.5) increases the risk of IPF. In order to recover from PM2.5-induced lung injury, alveolar epithelial cells need to be repaired and regenerated to maintain lung function. Type 2 alveolar epithelial cells (AEC2) are stem cells in the adult lung that contribute to the lung repair process through complex signaling. Our previous studies demonstrated that RAB6, a RAS family member lowly expressed in lung cancer, inhibited lung cancer stem cell self-renewal, but it is unclear whether or not and how RAB6 may regulate AEC2 cell proliferation and self-renewal in PM2.5-induced pulmonary fibrosis. Here, we demonstrated that knockout of RAB6 inhibited pulmonary fibrosis, oxidative stress, and AEC2 cell death in PM2.5-injured mice. In addition, knockout of RAB6 decreased Dickkopf 1(DKK1) autocrine and activated proliferation, self-renewal, and wnt/β-catenin signaling of PM2.5-injured AEC2 cells. RAB6 overexpression increased DKK1 autocrine and inhibited proliferation, self-renewal and wnt/β-catenin signaling in AEC2 cells in vitro. Furthermore, DKK1 inhibitors promoted proliferation, self-renewal and wnt/β-catenin signaling of RAB6 overexpressing AEC2 cells, and attenuated PM2.5-induced pulmonary fibrosis in mice. These data establish RAB6 as a regulator of DKK1 autocrine and wnt/β-catenin signal that serves to regulate AEC2 cell proliferation and self-renewal, and suggest a mechanism that RAB6 disruption may promote AEC2 cell proliferation and self-renewal to enhance lung repair following PM2.5 injury.

Karyopherin nuclear transport receptors play important roles in tumour development and drug resistance and have been reported as potential biomarkers and therapeutic targets for tumour treatment. However, IPO5, one of the karyopherin nuclear transport receptor family members, remains largely uncharacterized in tumour progression. The TCGA data, quantitative reverse transcription-PCR (qRT-PCR), western blotting, and IHC analyses were used to detect IPO5 expression in CRC tissues. A series of in vivo and in vitro experiments was utilized to demonstrate the function of IPO5 in CRC tissues. Mass spectrometry (MS), CO-IP technology, subcellular fractionation, and immunofluorescence were utilized to investigate the possible mechanisms of CRC. IPO5 was highly expressed and positively correlated with the clinicopathological characteristics of colorectal cancer tissues. Functional experiments indicated that IPO5 could promote the development of CRC. Mechanistically, we screened RASAL2, one cargo of IPO5, and further confirmed that IPO5 bound to the NLS sequence of RASAL2, mediating RASAL2 nuclear translocation and inducing RAS signal activation, thereby promoting the progression of CRC. Together, our results indicate that IPO5 is overexpressed in colorectal cancer cells. By transporting RASAL2, IPO5 may play a crucial role in CRC.

Fine particulate matter (PM2.5) airborne pollution increases the risk of chronic respiratory diseases, such as idiopathic pulmonary fibrosis (IPF), which is characterized by non-specific inflammation of the interstitial lung and extensive deposition of collagen fibers. Type 2 alveolar epithelial cells (AEC2s) are alveolar stem cells in the adult lung that contribute to the lung repair process through complex signaling. Our previous studies demonstrated that OGG1, a kind of DNA repair enzyme, have a critical role in protecting cells from oxidative damage and apoptosis induced by PM2.5, but the contribution of OGG1 in proliferation and self-renewal of AEC2s is not known. Here, we constructed OGG1^-/-mice to test the effect and mechanism of OGG1 on PM2.5-induced pulmonary fibrosis and injury in vivo. We detected proliferation and self-renewal of OGG1 overexpression or OGG1 knockout AEC2s after PM2.5 injury by flow cytometry and clone formation. We observed that knockout of OGG1 aggravated pulmonary fibrosis, oxidative stress, and AEC2 cell death in PM2.5-injured mice. In addition, OGG1 is required for the proliferation and renewal of AEC2s after PM2.5 injury. Overexpression of OGG1 promotes the proliferation and self-renewal of AEC2s by inhibiting PM2.5-mediated oxidative stress and NF-κB signaling hyperactivation in vitro. Furthermore, NF-κB inhibitors promoted proliferation and self-renewal of OGG1-deficient AEC2s cells after PM2.5 injury, and attenuated PM2.5-induced pulmonary fibrosis and injury in mice. These data establish OGG1 as a regulator of NF-κB signal that serves to regulate AEC2 cell proliferation and self-renewal, and suggest a mechanism that inhibition of the NF-κB signaling pathway may represent a potential therapeutic strategy for IPF patients with low-expression of OGG1.

Background: Glioma, the most common brain tumor, is a heterogeneous group of glia-derived tumors, the majority of which have characteristics of diffuse infiltration and immunosuppression. The LGALS protein family is a large class of sugar-binding proteins. Among them, LGALS3 has been reported to promote tumor development and progression in some cancers. However, the clinical significance and biological functions of LGALS3 in glioma remain virtually unknown. The purpose of our research is to detect LGALS3 expression and its prognostic value in glioma and reveal the relationship between its expression and the clinico/molecular-pathological features of patients and immune cell infiltration. Methods: LGALS3 protein expression was examined by immunohistochemistry. The mRNA expression data of LGALS3 was downloaded and analyzed from TCGA and Rembrandt datasets. The association between LGALS3 and glioma clinically relevant diagnostic/molecular markers (IDH, 1p19q, ATRX, MGMT, and TERT) was examined using the Chi-Squared (χ²) test. The correlation between LGALS3 expression and the infiltration of multiple intra-tumoral immune cell types, including B cells (CD20), T cells (CD4 and CD8), macrophages (CD68), and M2 tumor-associated macrophages (CD163), was evaluated by Spearman correlation analysis. Kaplan-Meier analysis and the Cox regression analysis were applied to evaluate the prognostic value of LGALS3 in glioma. The log-rank test was used to evaluate Kaplan-Meier results for significance. Results: Out of all 304 glioma cases, LGALS3 protein was expressed in 125 glioma cases (41.1%, 125/304), with 69.2% (9/13) in WHO I, 9.8% (8/82) in WHO II, 34.2% (26/76) in WHO III, and 61.7% (82/133) in WHO IV. The expression of LGALS3 was correlated with patient age, WHO grade, PHH3 (mitosis), Ki67 index, IDH, 1p/19q codeletion, and TERT promoter status. LGALS3 was an independent poor prognostic marker in diffusely infiltrating gliomas and was positively correlated with immune cell infiltration, particularly CD163+ tumor-associated macrophages in the TCGA dataset, Rembrandt dataset, and our SYSUCC cohort (R = 0.419, 0.627, and 0.724). Conclusion: LGALS3 was highly expressed in pilocytic astrocytoma, GBM, and IDH wild-type LGG. It served as a poor prognostic marker in diffusely infiltrating gliomas. Based on its prognostic significance and strong correlation with CD163+ TAMs, it may act as an important therapeutic target for human glioma.

Background: We previously reported that the long non-coding RNA (lncRNA) CASC11 promotes colorectal cancer (CRC) progression as an oncogene by binding to HNRNPK. However, it remains unknown whether CASC11 can act as a competitive endogenous RNA (ceRNA) in CRC. In this study, we focused on the role of CASC11 as a ceRNA in CRC by regulating miR-646 and miR-381-3p targeting of RAB11FIP2.Methods: We identified the target microRNAs (miRNAs) of CASC11 and the target genes of miR-646 and miR-381-3p using bioinformatic methods. A dual-luciferase reporter assay was performed to validate the target relationship. Quantitative real-time PCR (qRT-PCR), western blotting (WB), and immunohistochemistry (IHC) were used to measure the RNA and protein expression levels. Rescue experiments in vitro and in vivo were performed to investigate the influence of the CASC11/miR-646 and miR-381-3p/RAB11FIP2 axis on CRC progression.Results: We found that CASC11 binds to miR-646 and miR-381-3p in the cytoplasm of CRC cells. Moreover, miR-646 and miR-381-3p inhibitors reversed the suppressive effect of CASC11 silencing on CRC growth and metastasis in vitro and in vivo. We further confirmed that RAB11FIP2 is a mutual target of miR-646 and miR-381-3p. The expression levels of CASC11 and RAB11FIP2 in CRC were positively correlated and reciprocally regulated. Further study showed that CASC11 played an important role in regulating PI3K/AKT pathway by miR-646 and miR-381-3p/RAB11FIP2 axis.Conclusion: Our study showed that CASC11 promotes the progression of CRC as a ceRNA by sponging miR-646 and miR-381-3p. Thus, CASC11 is a potential biomarker and a therapeutic target of CRC.