LAMC2 mitigates ER stress by enhancing ER-mitochondria interaction via binding to MYH9 and MYH10.

Highly proliferative and metastatic tumors are constantly exposed to both intrinsic and extrinsic factors that induce adaptation to stressful conditions. Chronic adaptation to endoplasmic reticulum (ER) ER stress is common to many different types of cancers, and poses a major challenge for acquired drug resistance. Here we report that LAMC2, an extracellular matrix protein upregulated in many types of cancers, is localized in the ER of lung, breast, and liver cancer cells. Under tunicamycin-induced ER stress, protein level of LAMC2 is upregulated. Transfection of cancer cells with LAMC2 resulted in the attenuation of ER stress phenotype, accompanied by elevation in mitochondrial membrane potential as well as reduction in reactive oxygen species (ROS) levels and apoptosis. In addition, LAMC2 forms protein complexes with MYH9 and MYH10 to promote mitochondrial aggregation and increased ER-mitochondria interaction at the perinuclear region. Moreover, overexpression of LAMC2 counteracts the effects of ER stress and promotes tumor growth in vivo. Taken together, our results revealed that in complex with MYH9 and MYH10, LAMC2 is essential for promoting ER-mitochondria interaction to alleviate ER stress and allow cancer cells to adapt and proliferate under stressful conditions. This study provides new insights and highlights the promising potential of LAMC2 as a therapeutic target for cancer treatment.

Knowledge, attitude, and practice toward self-control of dental plaque among patients with periodontal diseases: a cross-sectional study.

BACKGROUND: The development of periodontal disease is closely linked to individual oral healthcare behaviors. This study aimed to investigate the knowledge, attitude, and practice (KAP) toward the self-control of dental plaque among patients with periodontal diseases. METHODS: This cross-sectional study was conducted at Jinan Stomatological Hospital between July 2022 and September 2022 through a self-administrated questionnaire for patients with periodontal diseases. RESULTS: A total of 563 participants were included. Among them, 147 (26.11%) had gingivitis and 416 (73.89%) had periodontitis. Participants' knowledge, attitude, and practice scores were 8.71 ± 2.81 (range 0-12), 39.82 ± 3.69 (range 10-50), 33.13 ± 5.91 (range 11-55), respectively. The multivariate logistic regression analysis showed that the knowledge [odds ratio (OR) = 1.212, 95% confidence interval (CI): 1.097-1.339, P < 0.001], attitude (OR = 1.132, 95% CI: 1.070-1.198, P < 0.001), occupation, especially in the commercial and service industry (OR = 0.488, 95% CI: 0.221-1.080, P = 0.007), and income of 10,000-20,000 yuan (OR = 0.476, 95% CI: 0.258-0.877, P = 0.017) were independently associated with good practice. CONCLUSIONS: Chinese patients with periodontal diseases demonstrated satisfactory knowledge and attitudes regarding oral hygiene, but the practical aspects need more promotion and training, especially in daily brushing frequency, usage of oral irrigator and interdental brush. Individualized approach should consider patients' knowledge, attitudes, occupation and income level.

LAMC2 promotes EGFR cell membrane localization and acts as a novel biomarker for tyrosine kinase inhibitors (TKIs) sensitivity in lung cancer.

The epidermal growth factor receptor (EGFR) is one of the first and most prominent driver genes known to promote malignant lung cancer. Investigating regulatory mechanisms beyond ligand-receptor binding, phosphorylation, and receptor kinase activation as means of EGFR signaling activation is important for improving EGFR-targeted therapy. Here, we report that Laminin-5γ-2 (LAMC2) retained high oncogenic capacity in lung cancer, silencing LAMC2 inhibited EGFR-induced cell proliferation and tumor growth in vivo. Deletion mutation experiments showed that both the EGF-Lam and LamB regions of LAMC2 are necessary for EGFR receptor binding, and that LAMC2 and EGFR were found to co-localize at the endoplasmic reticulum (ER) membrane. In addition, LAMC2 overexpression enhanced EGFR membrane deposition and promoted EGFR transport from the ER. Moreover, LAMC2 was necessary for preventing EGFR protein degradation via ubiquitination. Lastly, our study showed that high LAMC2 expression is positively associated with response to gefitinib (EGFR tyrosine kinase inhibitor) treatment. Overall, our study revealed a new regulatory mechanism of LAMC2 in promoting EGFR protein expression and stability by facilitating ER transport and preventing protein degradation via ubiquitination. Moreover, LAMC2 may serve as a stratifying biomarker for patients suitable for EGFR-TKI treatment.

The RNA binding protein MEX3A promotes tumor progression of breast cancer by post-transcriptional regulation of IGFBP4.

PURPOSE: Breast cancer (BC) is the most frequent malignant tumor in women worldwide with exceptionally high morbidity. The RNA-binding protein MEX3A plays a crucial role in genesis and progression of multiple cancers. We attempted to explore its clinicopathological and functional significance in BC in which MEX3A is expressed. METHODS: The expression of MEX3A detected by RT-qPCR and correlated the results with clinicopathological variables in 53 BC patients. MEX3A and IGFBP4 profile data of BC patients were downloaded from TCGA and GEO database. Kaplan-Meier (KM) analysis was used to estimate the survival rate of BC patients. Western Blot, CCK-8, EdU, colony formation and flow cytometry were performed to investigate the role of MEX3A and IGFBP4 in BC cell proliferation, invasion and cell cycle in vitro. A subcutaneous tumor mouse model was constructed to analyze in vivo growth of BC cells after MEX3A knockdown. The interactions among MEX3A and IGFBP4 were measured by RNA pull-down and RNA immunoprecipitation. RESULTS: The expression of MEX3A was upregulated in BC tissues compared to adjacent tissues and high expression of MEX3A was associated with poor prognosis. Subsequent in vitro studies demonstrated that MEX3A knockdown inhibited BC cells proliferation and migration, as well as xenograft tumor growth in vivo. The expression of IGFBP4 was significantly negatively correlated with MEX3A in BC tissues. Mechanistic investigation showed that MEX3A binds to IGFBP4 mRNA in BC cells, decreasing IGFBP4 mRNA levels, which further activated the PI3K/AKT and other downstream signaling pathways implicated cell cycle progression and cell migration. CONCLUSION: Our results indicate that MEX3A plays a prominent oncogenic role in BC tumorigenesis and progression by targeting IGFBP4 mRNA and activating PI3K/AKT signaling, which can be used as a novel therapeutic target for BC.

MAD2L1 is transcriptionally regulated by TEAD4 and promotes cell proliferation and migration in colorectal cancer.

The molecular mechanism of network regulation in the occurrence and development of colorectal cancer (CRC) has been constantly improved. Here, we investigated the biological effects of TEAD4-MAD2L1 axis on proliferation and metastasis of human CRC cells. This study revealed that the expressions of MAD2L1 and TEAD4 in CRC tissues and CRC cell lines were significantly higher than those in adjacent epithelial tissues and normal intestinal epithelial cell line NCM460, and their expressions were significantly positively correlated; Moreover, inhibiting the expression of MAD2L1 or TEAD4 can inhibit the proliferation and migration of CRC cells and promote apoptosis. In addition, the promoter region of MAD2L1 gene has a TEAD4 binding site (motif sequence), and the transcription of MAD2L1 is positively regulated by TEAD4 protein; The inhibition of promotion/migration and promotion of apoptosis of CRC cells by silencing TEAD4 can be saved by the high expression of MAD2L1. In conclusion, our study suggests that the transcription and expression of MAD2L1 is regulated by TEAD4, which further promotes the proliferation and migration of CRC cells in vitro and in vivo, and inhibits apoptosis. MAD2L1 and TEAD4 are potential biomarkers for colorectal cancer.

Crosstalk between extracellular vesicles and tumor-associated macrophage in the tumor microenvironment.

In concert with hijacking key genes to drive tumor progression, cancer cells also have the unique ability to dynamically interact with host microenvironment and discreetly manipulate the surrounding stroma, also known as the tumor microenvironment (TME), to provide optimal conditions for tumor cells to thrive and evade host immunity. Complex cellular crosstalk and molecular signaling between cancer cells, surrounding non-malignant cells, and non-cellular components are involved in this process. While intercellular communication traditionally centers around chemokines, cytokines, inflammatory mediators, and growth factors, emerging pathways involving extracellular vesicles (EVs) are gaining increasing attention. The immunosuppressive TME is created and maintained in part by the large abundance of tumor-associated macrophages (TMAs), which are associated with drug resistance, poor prognosis, and have emerged as potential targets for cancer immunotherapy. TMAs are highly dynamic, and can be polarized into either M1 or M2-like macrophages. EVs are efficient cell-cell communication molecules that have been catapulted to the center of TMA polarization. In this article, we provide detailed examination of the determinative role of EVs in sustaining the TME through mediating crosstalk between tumor cells and tumor-associated macrophages.

MECP2 promotes the migration and invasion of gastric cancer cells by modulating the Notch1/c-Myc/mTOR signaling pathways by suppressing FBXW7 transcription.

Methyl-CpG-binding protein 2 (MECP2), an epigenetic regulatory factor, promotes the carcinogenesis and progression of a number of cancers. However, its role in the migration and invasion of gastric cancer (GC), as well as the underlying molecular mechanisms, remain unclear. In this study, we found that MECP2 promoted the migration, invasion and metastasis of GC cells. Investigation of the molecular mechanism revealed that MECP2 repressed F-box and WD40 domain protein 7 (FBXW7) transcription in GC by binding to the methylated CpG sites in the FBXW7 promoter region. MECP2 expression was markedly negatively correlated with the FBXW7 level in GC tissues. FBXW7 expression was significantly downregulated in GC tissues and cell lines, and low FBXW7 expression was correlated with unfavorable clinicopathologic features. FBXW7 inhibited cell migration and invasion by regulating the Notch1/c-Myc/mTOR signaling pathways, and knockdown of FBXW7 reversed the effects of silencing MECP2. Moreover, MECP2 upregulated the Notch1/c-Myc/mTOR signaling pathways by inhibiting FBXW7 expression at the transcriptional level. This study demonstrates that MECP2 promotes the migration and invasion of GC cells by modulating the Notch1/c-Myc/mTOR signaling pathways via suppression of FBXW7 transcription. These findings suggest that MECP2 may be a novel effective therapeutic target in GC.

Bioinformatics analysis of prognostic value and immunological role of MeCP2 in pan-cancer.

Methyl-CpG-binding protein 2(MeCP2) is an important epigenetic regulatory factor that promotes many tumor developments, such as liver cancer, breast cancer, and colorectal cancer. So far, no pan-cancer analysis has been reported. Therefore, this study aims to explore pan-cancer's prognostic value, immune infiltration pattern, and biological function. We used bioinformatics methods to analyze the expression and prognostic significance of MeCP2, and the relationship between MeCP2 and clinicopathological parameters, genetic variation, methylation, phosphorylation, immune cell infiltration, and biological function in pan-cancer from using a public database. The results showed that expression of MeCP2 was up-regulated in 8 cancers and down-regulated in 2 cancers, which was remarkably correlated with the prognosis, pathological stage, grade and subtype of cancers. The promoter methylation level of MeCP2 DNA was decreased in bladder urothelial carcinoma (BLCA), breast invasive carcinoma (BRCA), liver hepatocellular carcinoma (LIHC), prostate adenocarcinoma (PRAD), uterine corpus endometrial carcinoma (UCEC), testicular germ cell tumors (TGCT), and stomach adenocarcinoma (STAD);decreased phosphorylation of S25, S90, S92, S241, S286, S325 and S435 was found in MeCP2, such as UCEC, lung adenocarcinoma (LUAD), ovarian serous cystadenocarcinoma (OV), colon adenocarcinoma (COAD), and kidney renal clear cell carcinoma (KIRC). Furthermore, MeCP2 expression was significantly associated with multiple immunomodulators and immune cell infiltration levels across most tumors. Therefore, our pan-cancer explored the prognostic markers and immunotherapeutic value of MeCP2 in different cancers.

To Explore and Analyze the Safety and Clinical Efficacy of Periocline-Assisted Periodontal Basic Therapy on Chronic Periodontitis.

Objective: This study aimed to investigate and analyse the clinical efficacy and safety of periocline-assisted periodontal foundation in the therapy of chronic periodontitis. Methods: From May 2018 to January 2021, 108 patients with chronic periodontitis were treated at our institution and randomly assigned equally to either the control or the experimental group. The plaque index (PLI), sulcus bleeding index (SBI), probing depth (PD), and periodontal attachment level (AI) were evaluated before and after periodontal basic therapy in the control group and periocline as an adjunct in the experimental group. Lactobacillus (LB) and Porphyromonas gingivalis (PG) concentrations in saliva were measured before and after therapy, and adverse responses during treatment were noted. Results: The levels of PLI, SBI, PD, and AI in the two groups were significantly lower in both groups at 1 and 3 months posttreatment compared to baseline; the levels of PLI and SBI were higher, and the levels of PD and AI were lower at 3 months after treatment compared to 1 month after treatment; compared with the control group at 1 month and 3 months after treatment, the levels of PLI, SBI, PD, and AI in the experimental group were lower than those in the control group (P < 0.05). The LB level was higher and the PG level was lower in both groups compared to baseline at 1 and 3 months posttreatment. The LB level was higher and the PG level was lower at 3 months posttreatment compared to 1 month after treatment. Compared with the control group at 1 month and 3 months after treatment, the LB level was higher, and the PG level was lower in the experimental group (P < 0.05). No significant adverse effects were observed in either group during the treatment period. Only 1 patient in the experimental group had mild gastrointestinal reactions, mainly nausea, without obvious neurological symptoms or abnormal blood changes, which did not affect the treatment. Conclusion: Periodontal fundamental therapy with perioclines may be a potential treatment for persistent periodontitis. It improves the primary clinical indicators, increases dysbacteriosis control, and has a strong safety profile. It could effectively control the development of clinical symptoms of periodontitis and reduce tissue destruction, with obvious clinical treatment effects. It could be used as the first choice for topical treatment of chronic periodontitis. It is recommended for further study by a wide range of researchers.

Pt3R5G inhibits colon cancer cell proliferation through inducing ferroptosis by down-regulating SLC7A11.

AIMS: Colon cancer (CC) is a prevalent malignancy worldwide and is one of the most easily altered cancers by dietary regulation. Petunidin 3-O-[rhamnopyranosyl-(trans-p-coumaroyl)]-5-O-(ß-D-glucopyranoside) (Pt3R5G) isolated and purified from Lycium ruthenicum Murray, which exhibits highly efficient antioxidant activity and specific anticancer effects, is the flavonoids compound. We aimed to study the effect of Pt3R5G on CC cells and elucidate the potential underlying mechanisms. MAIN METHODS: Cell proliferation was measured by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and colony formation assays. Cell cycle, cell apoptosis and reactive oxygen species (ROS) analysis were performed by flow cytometry. RNA-sequencing was performed to elucidate the potential underlying mechanisms. The lipid peroxidation level of cells was detected by malondialdehyde (MDA) assay. The mitochondrial morphology of cells was inspected using a transmission electron microscope. Additionally, we overexpressed SLC7A11 to perform rescue experiments. In vivo, xenograft mice assay was performed to verify the effect of Pt3R5G on the growth of colon cancer. KEY FINDINGS: Pt3R5G reduced the cell activity by blocking the cell cycle in G0/G1 phase, inducing the apoptosis and ferroptosis in RKO cells. The overexpressed of SLC7A11, a significantly down-regulated expression gene caused by Pt3R5G, rescued the cell proliferation inhibition and ferroptosis process. Furthermore, Pt3R5G inhibited tumor growth in nude mice. Our study suggests that Pt3R5G inhibits RKO cell proliferation through mainly reducing ferroptosis by down-regulated SLC7A11. SIGNIFICANCE: As a potential therapeutic drug, Pt3R5G showed efficient anticancer activity through a variety of pathways.

SERPINA5 promotes tumour cell proliferation by modulating the PI3K/AKT/mTOR signalling pathway in gastric cancer.

SERPINA5 belongs to the serine protease inhibitor superfamily and has been reported to be lowly expressed in a variety of malignancies. However, few report of SERPINA5 in gastric cancer has been found. The purpose of this study was to determine the role of SERPINA5 in GC and to investigate potential tumorigenic mechanisms. We performed qPCR to determine the level of SERPINA5 expression in GC. We used public databases to evaluate whether SERPINA5 could be utilized to predict overall survival and disease-free survival in GC patients. We also knocked down the expression of SERPINA5 and evaluated its effect on cell proliferation and migration. Furthermore, we explored the signal pathways and regulatory mechanisms related to SERPINA5 functions. According to our findings, SERPINA5 was shown to exhibit high expression in GC. Notably, SERPINA5 was prognostic in GC with high expression being unfavourable. SERPINA5 was further observed to promote GC tumorigenesis by modulating GC cell proliferation ability. Mechanically, SERPINA5 could inhibit CBL to regulate the PI3K/AKT/mTOR signalling pathway, thereby promoting GC carcinogenesis progression. These results highlight the important role of SERPINA5 in GC cell proliferation and suggest that SERPINA5 could be a novel target for GC treatment and a predictor for GC prognosis.

LGR6 Acts as an Oncogene and Induces Proliferation and Migration of Gastric Cancer Cells.

Leucine rich repeat containing G protein-coupled receptor 6 (LGR6) belongs to the G protein-coupled receptor family, and it exhibits up-regulated expression in various types of human cancer. However, there are few reports of LGR6 contributing to gastric cancer (GC). Herein, we investigated the function of LGR6 and associated tumorigenic mechanisms in GC. LGR6 expression in GC was analyzed in the cancer genome atlas (TCGA) dataset and further confirmed in GC cell lines and fifteen paired tissue samples via quantitative real-time polymerase chain reaction (qRT-PCR). LGR6 expression was knocked down via small interfering RNA (siRNA), after which the impacts of silencing LGR6 on cell function were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT), cell colony formation, wound-healing, and cell cycle assays. Western blot was performed to explore signaling pathways and regulatory mechanisms associated with LGR6 function. In this study, we showed that LGR6 was at higher levels in GC cell lines and gastric adenocarcinoma tissues. We found that silencing LGR6 in MKN-45 and BGC-823 cells inhibited cell proliferation and migration ability, which accompanied with an obvious regulation of MMP-9, ß-catenin, CCNA2, CDK-2, and ERK1/2. In conclusion, this study demonstrated that LGR6 could act as an oncogene and may be a therapeutic target in GC.

The novel lncRNA GPC5-AS1 stabilizes GPC5 mRNA by competitively binding with miR-93/106a to suppress gastric cancer cell proliferation.

Long non-coding RNAs (lncRNAs) are of importance in the genesis and progression of gastric cancer (GC). GPC5-AS1 is a novel lncRNA associated with methyl-CpG-binding protein 2 (MeCP2), identified in our previous microarray analysis; however, the role of GPC5-AS1 in GC remains unknown. In the present study, we demonstrate that GPC5-AS1 is downregulated in GC cells and tissues, and this aberrant expression is regulated by MeCP2 through CpG site binding in the promoter region. Importantly, we also demonstrate that GPC5-AS1 overexpression suppresses cell proliferation, colony formation, and cell cycle transition; induces apoptosis in vitro; and inhibits tumorigenicity in vivo. The expression of the controversial gene GPC5 was downregulated in GC tissues, and elevated GPC5 level could inhibit GC cell growth. Mechanistically, we demonstrated that GPC5-AS1 stabilizes GPC5 mRNA by acting as a molecular sponge for miR-93 and miR-106a, thereby reducing GC tumor progression. In conclusion, our results suggest that GPC5-AS1 may play a pivotal role in GC and serve as a potential diagnostic biomarker and a powerful therapeutic target for GC.

The RNA-binding protein GRSF1 promotes hepatocarcinogenesis via competitively binding to YY1 mRNA with miR-30e-5p.

BACKGROUND: Dysregulation of RNA binding protein (RBP) expression has been confirmed to be causally linked with tumorigenesis. The detailed biological effect and underlying mechanisms of the RBP GRSF1 in hepatocellular carcinoma (HCC) remain unclear. METHODS: HCC cells with stable knockdown of GRSF1 were established using two sh-RNA-encoding lentiviruses. The functions of GRSF1 in HCC were explored using MTT, colony formation, flow cytometry, and Transwell assays and a xenograft model. Transcriptomic sequencing in GRSF1-deficient MHCC-97H cells was carried out to identify the downstream effector of GRSF1. The regulatory mechanisms among GRSF1, YY1 and miR-30e-5p were investigated via RNA immunoprecipitation, luciferase, RNA pull-down and ChIP assays. Several in vivo assays were used to assess the selectivity of the small-molecule compound VE-821 in HCC and to confirm the absence of general toxicity in animal models. RESULTS: GRSF1 was frequently increased in HCC tissue and cells and was associated with worse clinical outcomes. GRSF1 functions as a novel oncogenic RBP by enhancing YY1 mRNA stability, and the GUUU motifs within the YY1 3`UTR 2663-2847 were the specific binding motifs for GRSF1. YY1 feedback promoted GRSF1 expression by binding to the GRSF1 promoter. In addition, YY1 was a critical target of miR-30e-5p, which was confirmed in this study to inhibit HCC hepatocarcinogenesis. GRSF1 and miR-30e-5p competitively regulated YY1 by binding to its 3`UTR 2663-2847 region. Finally, we identified that VE-821 blocked HCC progression by inhibiting the GRSF1/YY1 pathway. CONCLUSION: This study revealed the interaction network among GRSF1, YY1 and miR-30e-5p, providing new insight into HCC pathogenesis, and indicated that VE821 may serve as a novel agent with potential for HCC treatment through inhibition of the GRSF1/YY1 axis.

MeCP2 drives hepatocellular carcinoma progression via enforcing HOXD3 promoter methylation and expression through the HB-EGF/EGFR pathway.

Homeobox D3 (HOXD3), a member of the homeobox family, was described to regulate tumorigenesis, invasion, metastasis, and angiogenesis in various tumor types. However, the molecular mechanisms regulating HOXD3 during hepatocellular carcinoma (HCC) migration, invasion, and angiogenesis remain elusive. In this study, we demonstrated that HOXD3 expression is enhanced by the binding of methyl-CpG-binding protein 2 (MeCP2), a methyl-CpG binding protein, together with CREB1to the hypermethylated promoter of HOXD3. Inhibition of HOXD3 eliminated the tumorigenic effects of MeCP2 on HCC cells. Furthermore, HOXD3 directly targeted the promoter region of heparin-binding epidermal growth factor (HB-EGF) via the EGFR-ERK1/2 cell signaling pathway and promoted invasion, metastasis, and angiogenesis of HCC in vitro and in vivo. Additionally, elevated expression of MeCP2, CREB1, and HB-EGF in HCC correlated with a poor survival rate. Our findings reveal the function of the MeCP2/HOXD3/HB-EGF regulatory axis in HCC, rendering it an attractive candidate for the development of targeted therapeutics and as a potential biomarker in patients with HCC.

MiR-22, regulated by MeCP2, suppresses gastric cancer cell proliferation by inducing a deficiency in endogenous S-adenosylmethionine.

This study investigated the effect of methyl-CpG-binding protein 2 (MeCP2) on miRNA transcription. Our results of miRNA chip assay and ChIP-seq showed that MeCP2 inhibited the expressions of numerous miRNAs by binding to their upstream elements, including not only the promoter but also the distal enhancer. Among the affected miRNAs, miR-22 was identified to remarkably suppress gastric cancer (GC) cell proliferation, arrest G1-S cell cycle transition, and induce cell apoptosis by targeting MeCP2, MTHFD2, and MTHFR. Understanding GC metabolism characteristics is the key to developing novel therapies that target GC metabolic pathways. Our study revealed that the metabolic profiles in GC tissues were altered. SAM (S-adenosylmethionine), a universal methyl donor for histone and DNA methylation, which is specifically involved in the epigenetic maintenance of cancer cells, was found increased. The production of SAM is promoted by the folate cycle. Knockdown of MTHFD2 and MTHFR, two key enzymes in folate metabolism and methyl donor SAM production, significantly suppressed GC cell proliferation. MiR-22 overexpression reduced the level of endogenous SAM by suppressing MTHFD2 and MTHFR, inducing P16, PTEN, and RASSF1A hypomethylation. In conclusion, our study suggests that miR-22 was inhibited by MeCP2, resulting in deficiency of endogenous SAM, and ultimately leading to tumor suppressor dysregulation.