Immune-related adverse events associated with immune checkpoint inhibitors for advanced gastric and gastroesophageal junction cancer: A meta-analysis.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have shown promising efficacy in treatment and clinical management of advanced gastric and gastroesophageal junction cancer. However, the inhibitors also cause immune-related adverse events (irAEs). The current systematic review and meta-analysis study aimed to investigate the incidence and nature of irAEs caused by ICIs. AIM: To investigate the incidence and nature of irAEs in advanced gastric and gastroesophageal junction cancer. METHODS: This systematic review was registered with PROSPERO (Reg. number: CRD42020152291). Data included in this study were collected from patients diagnosed with advanced gastric cancer or gastroesophageal junction cancer and treated with ICIs. A systematic literature search was conducted using the PubMed, EMBASE, and Cochrane Library databases. Meta-analysis was carried out using the single sample rate method. Synthesis and analysis of the data was conducted using Stata/SE and Review Manager Software. RESULTS: The patients enrolled in the present study included 14 patients from 14 case reports, 326 patients from 6 case series, and 1249 patients from 8 clinical trials. It was found that the overall incidence of irAEs was 16% [95% confidence interval (CI): 11-20] for all grades and 3% (95%CI: 2-4) for the severe grade. It was evident that the incidence of irAEs varied with the type of inhibitor and organs. A comparative study of the anti-programmed cell death receptor-1 (PD-1) and anti-programmed death receptor-ligand 1 (PD-L1) treatments showed that the anti-PD-1 group had a higher overall incidence of irAEs (20%) as compared with that of the anti-PD-L1 group (13%). Results of this study showed that the endocrine system experienced the highest incidence of organ-specific irAEs (7.4%), including hypothyroidism, hyperthyroidism, thyroiditis, diabetes, and adrenal insufficiency, followed by gastroenterology (2.2%), pulmonology (1.8%), neurology (1.4%), dermatology (1.4%), hematology (0.8%), and hepatology (0.7%). In clinical trials, it was found that the incidence of death related to irAEs was 1% (95%CI: 0-2.0), whereby colitis and interstitial lung diseases were the leading causes of death. CONCLUSION: It was evident that the incidence and nature of irAEs are both organ- and inhibitor-specific. The anti-PD-1 group had the highest incidence of all irAEs grades including the severe grades of irAEs. Early identification and management of irAEs allows clinical oncologists to effectively consider the pros and cons and hence enables them to strike a balance.

Altered Intrinsic Regional Spontaneous Brain Activity in Patients With Severe Obesity and Meibomian Gland Dysfunction: A Resting-State Functional Magnetic Resonance Imaging Study.

Purpose: To evaluate potential regional homogeneity (ReHo) cerebrum function lesions in people with severe obesity and meibomian gland dysfunction (SM) and probe the connection between aberrant cerebrum activity and clinical manifestations. Patients and Methods: An aggregation of 12 patients with SM, and 12 healthy controls (HCs) closely matched in age and gender were enrolled. We applied corneal confocal microscopy and fundus angiography to compare imaging distinctions between the two groups. SMs were required to carefully fill out the Hospital Anxiety Depression Scale (HADS) forms, and a correlation analysis was performed. ReHo was also utilized to appraise partial differences in spontaneous cerebrum function. Receiver operating characteristic (ROC) curves were created to partition ReHo values between patients with SM and the HCs. Results: ReHo values for the left cerebellum (LC), right fusiform gyrus (RFG), left inferior temporal gyrus (LITG), left rectus gyrus (LRG), right thalamus (RT), right caudate (RC), left insula (LI), and left thalamus (LT) of subjects with SM were notably higher than those of the HCs (P < 0.05). ReHo values of the right middle frontal gyrus (RMFG) in subjects with SM were decreased notably compared to the HCs (P < 0.05). ReHo values for the RMFG showed a negative correlation with the anxiety scores (ASs; r = -0.961, P < 0.001) and ReHo values for the RFG showed a positive correlation with the depression scores (DSs; r = 0.676, P = 0.016). The areas under the ROC curve were 1.000 (P < 0.001) for the RMFG, LC, LITG, LRG, RC, LI, and LT and 0.993 (P < 0.001) for the RFG and RT. The results from the ROC curve analysis indicated that changes in the ReHo values of some brain regions may help diagnose SM. Conclusion: Our research emphasized that patients with SM had lesions in synchronized neural activity in many encephalic areas. Our discoveries may provide beneficial information for exploring the neuromechanics of SM.

microRNA-15b-5p encapsulated by M2 macrophage-derived extracellular vesicles promotes gastric cancer metastasis by targeting BRMS1 and suppressing DAPK1 transcription.

BACKGROUND: Extracellular vesicles (EVs) derived from tumor-associated macrophages are implicated in the progression and metastasis of gastric cancer (GC) via the transfer of molecular cargo RNAs. We aimed to decipher the impact of microRNA (miR)-15b-5p transferred by M2 macrophage-derived EVs in the metastasis of GC. METHODS: Expression of miR-15b-5p was assessed and the downstream genes of miR-15b-5p were analyzed. GC cells were subjected to gain- and loss-of function experiments for miR-15b-5p, BRMS1, and DAPK1. M2 macrophage-derived EVs were extracted, identified, and subjected to co-culture with GC cells and their biological behaviors were analyzed. A lung metastasis model in nude mice was established to determine the effects of miR-15b-5p on tumor metastasis in vivo. RESULTS: miR-15b-5p was upregulated in GC tissues and cells as well as in M2 macrophage-derived EVs. miR-15b-5p promoted the proliferative and invasive potentials, and epithelial-mesenchymal transition (EMT) of GC cells. M2 macrophage-derived EVs could transfer miR-15b-5p into GC cells where it targeted BRMS1 by binding to its 3'UTR. BRMS1 was enriched in the DAPK1 promoter region and promoted its transcription, thereby arresting the proliferative and invasive potentials, and EMT of GC cells. In vivo experiments demonstrated that orthotopic implantation of miR-15b-5p overexpressing GC cells in nude mice displayed led to enhanced tumor metastasis by inhibiting the BRMS1/DAPK1 axis. CONCLUSIONS: Overall, miR-15b-5p delivered by M2 macrophage-derived EVs constitutes a molecular mechanism implicated in the metastasis of GC, and may thus be considered as a novel therapeutic target for its treatment.

ROCK2 disturbs MKP1 expression to promote invasion and metastasis in hepatocellular carcinoma.

Dual-specificity phosphatase-1 (DUSP1/MKP1) plays a key role in controlling various physiological and pathological phenomena, including tumor metastasis and invasion. However, the role of MKP1 in tumorigenesis is controversial. We showed that the expression of MKP1 in hepatocellular carcinoma (HCC) is significantly downregulated, and MKP1 is an independent predictor of poor prognosis. In in vitro and in vivo studies, we showed that MKP1 significantly inhibits the invasion and metastasis of HCC cells. Additionally, we found that low MKP1 expression is associated with the expression of ROCK2, which plays an important role in HCC. Our data suggest that MKP1 is crucial for ROCK2-mediated metastasis and invasion. Interestingly, we demonstrated that ROCK2 has opposite effects on protein and mRNA levels of MKP1, as it decreases the expression at the protein level and increases the expression at the mRNA level. We also identified the mechanism responsible for this incongruency; ROCK2 activates ERK1/2-ATF2 signaling, which leads to the increased mRNA expression of MKP1. At the same time, ROCK2 promotes the ubiquitin-mediated degradation of MKP1 by activating ERK1/2, therefore promoting the metastasis of HCC. In conclusion, our data provide new evidence for the biological and clinical significance of MKP1 as a potential biomarker. We demonstrate that ROCK2 disturbs the protein and mRNA expression of MKP1 in human HCC progression.

GPER mediates decreased chemosensitivity via regulation of ABCG2 expression and localization in tamoxifen-resistant breast cancer cells.

Rescue chemotherapy is usually the preferred treatment for patients with advanced estrogen receptor-positive (ER+) breast cancer with endocrinotherapy resistance. However, these patients often simultaneously show a poor response to cytotoxic drugs, and thus the detailed mechanism of this resistance needs to be further investigated. Our previous research indicated that the G-protein-coupled estrogen receptor (GPER) is a novel mediator of the development of multidrug resistance, including resistance to both endocrinotherapy and chemotherapy, and ATP binding cassette subfamily G member 2 (ABCG2) has been identified as an engine that confers cancer cells with chemoresistance by expelling xenobiotics and chemotherapeutics. Here, we are the first to show that the expression levels of GPER and ABCG2 are markedly increased in tamoxifen-resistant ER + metastases compared to the corresponding primary tumors. A plasma membrane expression pattern of GPER and ABCG2 was observed in patients with metastases. Furthermore, both ER modulator tamoxifen, GPER-specific agonist G1 and pure ER antagonist ICI 182,780 significantly enhanced ABCG2 expression in tamoxifen-resistant breast cancer cells (MCF-7R) but not in tamoxifen-sensitive cells (MCF-7). The activated downstream GPER/EGFR/ERK and GPER/EGFR/AKT signaling pathways were responsible for regulating the expression and cell membrane localization of ABCG2, respectively, in MCF-7R cells. Interestingly, the above phenomenon could be alleviated by inhibitors of both the indicated signaling pathways and by knockdown of GPER in MCF-7R cells. More importantly, the tamoxifen-induced GPER/ABCG2 signaling axis was shown to play a pivotal role in the development of chemotherapy (doxorubicin) resistance both in vitro and in vivo. The clinical data further revealed that tamoxifen-resistant patients with high GPER/ABCG2 signaling activation had poor progression-free survival (PFS) when given rescue anthracycline chemotherapy. Therefore, our data provide novel insights into GPER-mediated chemoresistance and provide a rationale for the GPER/ABCG2 signaling axis being a promising target for reversing chemoresistance in patients with advanced ER + tamoxifen-resistant breast cancer.

MicroRNA-125a-5p inhibits invasion and metastasis of gastric cancer cells by targeting BRMS1 expression.

Accumulating studies have demonstrated microRNAs (miRNAs/miRs) have an important role in multiple processes of human malignant tumor development and progression. Decreased expression of miR-125a-5p has been observed in several types of cancer, including gastric cancer (GC). However, the mechanism and exact function of miR-125a-5p in GC have not been largely elucidated. In the present study, reverse transcription-quantitative polymerase chain reaction indicated that the expression of miR-125a-5p was downregulated in GC tissues and cell lines compared with matched normal tissues (P<0.01) and normal gastric mucosa cell lines (P<0.01), respectively. Moreover, clinical pathological characteristics and Kaplan-Meier analysis indicated that a low expression of miR-125a-5p was not only associated with lymph metastasis, peritoneal dissemination and advanced tumor-node metastasis stage but also affected the prognosis of GC patients. Compared with miR-control-transfected GC cells, markedly decreased migration and invasion was observed in GC cells that overexpress miR-125a-5p. By contrast, increased metastasis and invasion were observed in miR-125a-5p-knocked down cells compared with the control. Furthermore, luciferase reporter assays indicated that breast cancer metastasis suppressor 1 (BRMS1) was a direct target of miR-125a-5p. Notably, a positive correlation between the levels of BRMS1 and miR-125a-5p in GC tissues was observed, and BRMS1 expression was indicated to be regulated by miR-125a-5p in GC cells. In conclusion, miR-125a-5p may act as a tumor suppressor by targeting the metastasis-inhibitory gene, BRMS1. The data suggesting that BRMS1 is a potential target gene of miR-125a-5p, may provide novel insight into miRNA regulation of human gene expression, and a useful target for gene therapy of GC.

PRL-3 promotes the peritoneal metastasis of gastric cancer through the PI3K/Akt signaling pathway by regulating PTEN.

Peritoneal metastasis is the most frequent cause of death in patients with advanced gastric carcinoma (GC). The phosphatase of regenerating liver-3 (PRL-3) is recognized as an oncogene and plays an important role in GC peritoneal metastasis. However, the mechanism of how PRL-3 regulates GC invasion and metastasis is unknown. In the present study, we found that PRL-3 presented with high expression in GC with peritoneal metastasis, but phosphatase and tensin homologue (PTEN) was weakly expressed. The p-PTEN/PTEN ratio was also higher in GC with peritoneal metastasis than that in the normal gastric tissues. We also found the same phenomenon when comparing the gastric mucosa cell line with the GC cell lines. After constructing a wild-type and a mutant-type plasmid without enzyme activity and transfecting them into GC SGC7901 cells, we showed that only PRL-3 had enzyme activity to downregulate PTEN and cause PTEN phosphorylation. The results also showed that PRL-3 increased the expression levels of MMP-2/MMP-9 and promoted the migration and invasion of the SGC7901 cells. Knockdown of PRL-3 decreased the expression levels of MMP-2/MMP-9 significantly, which further inhibited the migration and invasion of the GC cells. PRL-3 also increased the expression ratio of p-Akt/Akt, which indicated that PRL-3 may mediate the PI3K/Akt pathway to promote GC metastasis. When we transfected the PTEN siRNA plasmid into the PRL-3 stable low expression GC cells, the expression of p-Akt, MMP-2 and MMP-9 was reversed. In conclusion, our results provide a bridge between PRL-3 and PTEN; PRL-3 decreased the expression of PTEN as well as increased the level of PTEN phosphorylation and inactivated it, consequently activating the PI3K/Akt signaling pathway, and upregulating MMP-2/MMP-9 expression to promote GC cell peritoneal metastasis.

[The experimental study of the effect of ASCs on the skin expansion rate in rabbit].

Objective: To explore the effect of adipose-derived stem cells (ASCs) on the skin expansion rate in rabbit. Methods: The rabbit ASCs were isolated from fat tissue and cultured in vitro. The ADSCs were identified by cell immunofluorescence and marked by Edu staining.20 new Zealand rabbits were randomly divided into experimental(n =10) and control group(n =10).An area of 1.5 cm ×1.5 cm on the one side back of each rabbit was tattooed and one 30 ml round expander was implanted subcutaneously. ASCs suspension (1 ml) was injected subcutaneously in the experimental group, while serum free DMEM medium(1 ml) in control group. The expansion was proceeded regularly under constant pressure for 4 weeks.The expanded tattooed square area was measured on the 7th,14th,28th day and analyzed statistically. The expanded skin was harvested for histological study. Immunohistochemical staining was used to detect the expression of vascular endothelial cell marker CD31,and the microvessel density determination. The expression of epidermal growth factor (EGF) and vascular endothelial growth factor(VEGF)was detected by ELISA for skin tissue specificity. Western Blot was used for detection of CK19 in the epidermal cells. Results: The expanded skin thickness and expansion rate in experimental group were significant higher than those in control group (P ＜ 0.05). Compared with control group, the expression of CK19,CD31 and EGF, VEGF, as well as the microvessel density were all markedly increased in experimental group(P ＜0.05). Conclusions: ASCs can increase the expansion rate of skin tissue by promotion of angiogenesis and tissue regeneration.

Methylation-associated silencing of miR-495 inhibit the migration and invasion of human gastric cancer cells by directly targeting PRL-3.

Phosphatase of regenerating liver-3 (PRL-3) is believed to be associated with cell motility, invasion, and metastasis. Our previous work found that PRL-3 is highly overexpressed in gastric cancer (GC) tissue with peritoneal metastasis and directly involved in the pathogenesis of GC peritoneal metastasis. Moreover, we further found that the down-regulation of endogenous miR-495 expression plays a causative role in over expression of PRL-3 in GC peritoneal metastasis. However, the molecular regulation mechanisms by which endogenous miR-495 expression is down-regulated and PRL-3 promotes GC peritoneal metastasis remain to be clearly elucidated. Some studies have shown that the promoter methylation is closely related to the miRNA gene expression. Therefore, in present study, based on our previous findings, we will analysis whether DNA methylation is a major cause of the down-expression of endogenous miR-495, which results in PRL-3 overexpression in GC peritoneal metastasis. Methylation specific PCR (MSP) and sodium bisulfite sequencing method (BSP) detected miR-495 gene promoter methylation status. We treated GC cell lines with 5-Aza-2'-deoxycytidine (5-Aza-dC) to make the gene promoter methylation inactivation. By treating with 5-Aza-dC the migration and invasion of GC cells were significantly inhibited. And the miR-495 was overexpressing, corresponds to the mRNA and protein levels of PRL-3 were reduced, the ability of invasion and metastasis was inhibited. This study suggest that miR-495 have tumor suppressor properties and are partially silenced by DNA hypermethylation in GC, will provide new strategies for prevention and treatment of GC peritoneal metastasis.

Methylation-associated silencing of MicroRNA-335 contributes tumor cell invasion and migration by interacting with RASA1 in gastric cancer.

MicroRNAs (miRNAs) are small non-coding RNAs that function as endogenous silencers of target genes, previous studies have shown that miR-335 play an important role in suppressing metastasis and migration in human cancer including gastric cancer (GC). However, the mechanisms which result in aberrant expression of miR-335 in GC are still unknown. Recent studies have shown that the silencing of some miRNAs is associated with DNA hypermethylation. In this study, we find the promoter of miR-335 we embedded in CpG island by accessing to bioinformatics data and the low expression of miR-335 in 5 gastric cell lines can be restored by 5-aza-2'-deoxycytidine (5-Aza-dC) treatment. So we postulated that the miR-335 genes undergo epigenetic inactivation in GC. Subsequently, in GC cells and tissues, we performed quantitative real-time PCR (RTQ-PCR) to assess the expression of miR-335, and methylation-specific PCR (MSP) and bisulfite sequence-PCR (BSP) to evaluate the DNA methylation status in the CpG islands upstream of MiR-335. The result showed that the expression of miR-335 was significantly reduce in gastric cancer cell lines and tumor tissues compared to matched normal gastric tissues, and cell lines, and which is inverse correlation with DNA hypermethylation of miR-335 both in GC cells lines and tissues, but not in normal tissues. In addition, we found that the lower miR-335 expression induced by abnormal methylation may be mainly involved in gastric cell invasion and metastasis in GC tissues. No statistical significance was found about miR-335 expression and methylation level between healthy individuals with and without H. pylori (HP) infection. Finally, we carry out miRNA transfection, RTQ-PCR and western blot assay to find the RAS p21 protein activator (GTPase activating protein) 1 (RASA1) may be the possible target genes which lead to the gastric cell invasion and metastasis, furthermore, the re-expression of endogenous miR-335 by 5-Aza-dC treatment can exert effects similar to exogenous miRNAs transfection. Taken together, our results suggest that miR-335 may be silenced by promoter hypermethylation and play important roles in gastric cell invasion and metastasis through its target genes, such as RASA1. Its methylation level might be a predictive epigenetic marker of GC and remodeling on the expression by demethylation can provided a potential therapeutic strategy.