Managing immune checkpoint inhibitor-associated gastritis: Insights and strategies.

Immune checkpoint inhibitors (ICIs) are widely used due to their effectiveness in treating various tumors. Immune-related adverse events (irAEs) are defined as adverse effects resulting from ICI treatment. Gastrointestinal irAEs are a common type of irAEs characterized by intestinal side effects, such as diarrhea and colitis, which may lead to the discontinuation of ICIs.

STX2 drives colorectal cancer proliferation via upregulation of EXOSC4.

AIMS: To explore the biological function and mechanism of Syntaxin2 (STX2) in Colorectal cancer (CRC) proliferation. MAIN METHODS: A series of gain- and loss-of-function analysis were conducted the to explore the biological function of STX2 in CRC proliferation in vivo and in vitro. Western blot, Co-immunoprecipitation (Co-IP) and the functional analyses were taken to analyze the regulative role of STX2 on Exosome Complex 4 (EXOSC4) in CRC proliferation; Immunohistochemistry (IHC) and Real-time quantitative polymerase chain reaction (qPCR) were used to further verify the relationship between the expression of STX2 and EXOSC4 in human CRC samples. KEY FINDINGS: Our study revealed that the over-expression of STX2 promoted CRC proliferation, while knockdown of STX2 repressed CRC proliferation; STX2 promoted CRC proliferation via increasing EXOSC4 protein; There was a positive correlation between STX2 and EXOSC4 expression. SIGNIFICANCE: The current data verify that STX2 drives the proliferation of CRC via increasing the expression of EXOSC4.

Hypermethylation Of ADHFE1 Promotes The Proliferation Of Colorectal Cancer Cell Via Modulating Cell Cycle Progression.

BACKGROUND: Colorectal cancer (CRC) is one of the most common malignancies worldwide. Studies have demonstrated that epigenetic modifications play essential roles in the development of CRC. ADHFE1 is a differentially expressed gene that has been reported to be hypermethylated in CRC. However, the role and mechanism of ADHFE1 in the proliferation of CRC remain unclear. MATERIALS AND METHODS: ADHFE1 expression was analyzed in CRC tissues by IHC and qRT-PCR, and the relationship between ADHFE1 expression and the clinicopathological parameters was analyzed. Cell proliferation were assessed by the in vitro and in vivo experimental models. GSEA assay was performed to explore the mechanism of ADHFE1 in the proliferation of CRC. Flow cytometry and Western blot were used to detect the activation of the cell cycle signaling. Bisulfite genomic sequence (BSP) assay was used to test the methylation degree of ADHFE1 gene promoter in CRC tissues. RESULTS: Here, we verified that ADHFE1 was down-regulated and hypermethylated in CRC tissues. The down-regulation of ADHFE1 was correlated with poor differentiation and advanced TNM stage of CRC patients. And ADHFE1 expression restored when the CRC cell line SW620 was treated with the demethylating agent 5-Aza-CdR. Overexpression of ADHFE1 inhibited the proliferation of CRC, while ADHFE1 knockdown promoted the proliferation of CRC cells in vitro and in vivo. Moreover, ADHFE1 overexpression could induce a significant G1-S cell cycle arrest in CRC cells and vice versa. CONCLUSION: Hypermethylation of ADHFE1 might promote cell proliferation by modulating cell cycle progression in CRC, potentially providing a new therapeutic target for CRC patients.

DSCAM-AS1 promotes tumor growth of breast cancer by reducing miR-204-5p and up-regulating RRM2.

Breast cancer (BC) is a common malignancy worldwide. More than 3 700 000 women die of BC every year. DSCAM-AS1 was overexpressed several kinds of cancer and miR-204-5p was lowly expressed, which indicated that miR-204-5p had anti-tumor activity and DSCAM-AS1 had pro-tumor activity. We intended to analyze DSCAM-AS1, miR-204-5p, and ribonucleotide reductase M2 (RRM2). Microarray analysis and quantitative Real Time fluorescence Polymerase Chain Reaction (qRT-PCR) were employed to determine DSCAM-AS1 and miR-204-5p expression. Luciferase reporter assay was applied to examine the target relationship between DSCAM-AS1, miR-204-5p, and RRM2. Cell Counting Kit-8 (CCK-8 assay), transwell assay, and flow cytometry were used to detect cell proliferation, invasion, and apoptosis. The expression of DSCAM-AS1, miR-204-5p, and RRM2 were confirmed by Western blot. We also conducted in vivo assay to verify the effect of DSCAM-AS1. DSCAM-AS1 was up-regulated, while miR-204-5p was down-regulated in BC tissues and cells. DSCAM-AS1 directly targeted miR-204-5p. DSCAM-AS1 promoted the proliferation and invasion of BC cells by reducing miR-204-5p and inhibiting miR-204-5p expression. DSCAM-AS1 expression was related to the expression of RRM2, and miR-204-5p could reverse the function of DSCAM-AS1. RRM2 was up-regulated in BC cells, and miR-204-5p inhibited RRM2 expression by targeting RRM2. Overexpression of RRM2 stimulated proliferation and cell invasion and impeded apoptosis. In vivo experiments showed that knockdown of DSCAM-AS1 decreased the tumorigenesis of BC cells, increased the expression of miR-204-5p. DSCAM-AS1 promoted proliferation and impaired apoptosis of BC cells by reducing miR-204-5p and enhancing RRM2 expression. DSCAM-AS1/miR-204-5p/RRM2 may serve as novel therapeutic targets for BC.

HPV16 E7 increases COX-2 expression and promotes the proliferation of breast cancer.

Breast cancer remains the leading cause of mortality worldwide. Human papilloma virus 16 (HPV16) may serve a function in the pathogenesis and development of breast cancer. However, the detection rate of HPV16 in breast carcinoma may vary by region. In the present study, the expression of HPV16 E7 in paraffin-embedded tissues from patients with breast cancer from North China was detected. Additionally, the molecular mechanisms underlying the function of HPV16 E7 in the proliferation of breast cancer cells were examined. The results demonstrated that the DNA of HPV16 E7 was detected in 30.5% of the samples, and that HPV16 E7 promoted the proliferation of breast cancer cells in vitro and in vivo. Additionally, HPV16 E7-mediated proliferation of breast cancer cells was suppressed in response to treatment with cyclooxygenase-2 (COX-2)-specific small interfering RNA and celecoxib. The results of the present study revealed that HPV16 E7 may promote the proliferation of breast cancer cells by upregulating COX-2, suggesting that COX-2 may be a potential therapeutic target for HPV16 E7-mediated progression of breast cancer.

Astragalus polysaccharide upregulates hepcidin and reduces iron overload in mice via activation of p38 mitogen-activated protein kinase.

Thalassemia is a genetic disease characterized by iron overload which is a major detrimental factor contributing to mortality and organ damage. The hepcidin secreted by liver plays an essential role in orchestrating iron metabolism. Lowering iron load in thalassemia patients by means of increasing hepcidin might be a therapeutic strategy. In this study, we first found that astragalus polysaccharide (APS) significantly increased hepcidin expression in HepG2 and L-02 cell lines originating from hepatocytes and mice liver, respectively. Following treatment with APS, the iron concentrations in serum, liver, spleen, and heart were significantly reduced in comparison to saline treated control mice. In further experiments, upregulation of interleukin-6 (IL-6) and enhanced p38 MAPK phosphorylation were detected in APS treated cells and mice, and as documented in previous studies, IL-6 and P38 MAPK phosphorylation are involved in the regulation of hepcidin expression. We also found that the effects of APS on upregulating hepcidin and IL-6 expressions could be antagonized by pretreatment with SB203580, an inhibitor of p38 MAPK signaling. These findings suggest that activation of p38 MAPK and release of IL-6 might mediate induction of hepcidin by APS. It is concluded that APS might have therapeutic implications in patients with iron overload, especially for thalassemia patients.

[Effects of sodium butyrate on acetylation of histone in gamma-globin gene promoter regions in K562 cells: a study using chromatin immunoprecipitation].

OBJECTIVE: To develop a real-time PCR-based chromatin immunoprecipitation (ChIP) assay for determining the effect of sodium butyrate on acetylation of histone in gamma-globin gene promoter regions in K562 cells. METHODS: K562 cells were grown in the presence or absence of 0.5 mmol/L sodium butyrate for 48 h, and 1=10(7) cells per group were used for real-time PCR-based ChIP with anti-acetylated histone H3 or H4 antibodies. The levels of acetylated histone H3 and H4 (acH3 and acH4) in Ggamma- and Agamma-globin gene promoter regions were measured. RESULTS: In the K562 cells with sodium butyrate treatment or without any treatment, the levels of acH3 or acH4 in Ggamma- or Agamma-globin gene promoter were higher than that in the necdin gene (negative control). Compared with the untreated K562 cells, the cells treated with 0.5 mmol/L sodium butyrate showed a 3.1-fold or 2.6-fold increase in acH3 or acH4 in Ggamma-globin gene promoter region, with also a 3.7-fold or 3.2-fold increase in acH3 or acH4 in Agamma-globin gene promoter region, respectively (P<0.01). CONCLUSION: We have successfully developed a real-time PCR-based ChIP assay for analyzing the acetylation of histone H3 and H4 in gamma-globin gene promoter regions. Our results support the role of sodium butyrate in increasing the level of acetylated histone in gamma-globin gene promoter regions.

[Isolation of E1A-related drug-sensitive new genes by suppression subtractive hybridization].

BACKGROUND & OBJECTIVE: It has been well demonstrated that E1A, as a tumor suppression gene, is capable of inhibiting the growth and metastasis of different tumors, and reversing the malignant phenotype. Particularly, the gene possesses the ability to greatly enhance the drug-sensitivity of tumor cells to several antitumor agents, and also increase the radio-sensitivity. However, the associated genes through which E1A can exert its antitumor functions still remain unknown. The aim of this study was to isolate E1A anticancer-related genes,which were differentially expressed in drug-sensitive tumor cells using suppression subtractive hybridization (SSH). METHODS: To construct SSH library of human lymph node metastasis tumor cells (LN686) using the mRNA from LN686 cells treated by E1A protein and the parental LN686 cells as tester and driver, respectively. Positive clones in the library were selected randomly, and dot blot was used for the analysis of expression pattern of the differentially expressed-gene fragments. The sequences of cDNA fragments were analyzed and compared with that in GenBank. The mRNA levels of the novel genes in tester and driver were determined by semi-quantitative RT-PCR analysis. RESULTS: The SSH library contained about 7000 positive clones. Random analysis of 384 clones with PCR demonstrated that 362 clones contained inserted fragments. The consequence of dot blot demonstrated that these genes were over-expressed in the tester compared to the driver significantly. The 362 clones were sequenced and BLAST analysis was conducted, 10 clones are shown to be novel ESTs, and were registered in GenBank. The mRNA levels of the seven novel genes were over-expressed in LN686 cells treated by E1A protein compared to those of parental LN686 cells by semi-quantitative RT-PCR analysis, and the difference of mRNA expression was approximately 3-8 times. CONCLUSION: Ten novel gene fragments were isolated by the SSH technology, and it provided the basis for further cloning their full- length genes and studying their functions.

[Expression of HPV16-E6 and E7 oncoproteins in squamous cell carcinoma tissues of esophageal cancer and non-cancer tissues].

BACKGROUND & OBJECTIVE: Evidences indicate that high-risk type human papillomavirus (HPV) are closely associated with the carcinogenesis, progression and transformation of several kinds of human tumors. This study was designed to determine the expression of HPV16- E6 and E7 oncoproteins in normal tissues, dysplasia tissues, and carcinoma tissues of patients with esophageal cancer and to investigate the biological significance of high-risk type HPV in the esophageal squamous cell carcinogenesis. METHODS: HPV16-E6 and E7 oncoproteins were determined using immunohistochemical staining in normal mucosa tissues (70 cases), dysplasia tissues (43 cases), and carcinoma tissues (18 cases). RESULTS: The positive rates of HPV16-E6 in the tissues of normal mucosa, dysplasia, and carcinoma of esophagus patients were 59.3%,88.4%,and 83.3%,respectively; the positive rates of HPV16-E7 protein were 62.1%, 90.7%, and 88.9%, respectively. The positive rates of HPV16-E6 and E7 in dysplasia and carcinoma of esophagus were significantly higher than those in normal mucosa (P< 0.05). Double expression of HPV16-E6 and E7 in normal mucosa was 25.7%, while in dysplasia and carcinoma were 88.3% and 83.3%,respectively. CONCLUSION: HPV16-E6 and E7 are highly associated with esophageal squamous cell carcinogenesis. And cooperation of HPV16-E6 and E7 may play an important role in genesis of esophageal squamous carcinoma.

[Effect of E1A gene on in vitro growth inhibition and radiochemosensitivity of lymph node metastasis cells of human head and neck squamous cell carcinoma].

BACKGROUND & OBJECTIVE: Adenovirus type 5 early region 1A (E1A) gene has been found to be a tumor suppression gene recently. The protein of E1A gene regulates the expression of many cellular genes positively or negatively, and possesses the activities of inducing differentiation of tumor cell, reversing of malignant phenotype, anti-carcinogenesis and anti-metastasis. Study of E1A protein on the treatment of lymph node metastasis of human head and neck squamous cell carcinoma (HNSCC) was not reported. This study was designed to investigate the growth inhibition and radiochemosensitivity of E1A gene on human lymph node metastasis cell line 686LN-1 derived from the patient with human tongue squamous cell carcinoma in vitro and its mechanism. METHODS: The pcDNA3-E1A recombinant plasmid, designed for high-level expression of E1A gene in a variety of eukaryotic cell lines,was transfected into 686LN-1 cells mediated by lipofectamine. To observe the growth inhibition of E1A gene on the cells, the growth curve and doubling time were investigated. Cells before and after transfection were treated with cisplatin, paclitaxel, bleomycin, and 5-fluorouracil (5-FU) for 24 hours or irradiation, respectively, then the changes of sensitivity were tested by MTT assay. The redistributions of cell cycle were analyzed by flow cytometry. Immunocytochemical staining was used to detect the expression of p53 and HER-2/neu. RESULTS: Compared with the vector-transfected cells (686LN-1-vect cells), the E1A-transfected cells (686LN-1-E1A cells) grew slowly, and the doubling time elongated (1.41-fold). 686LN-1-E1A cells showed distinct sensitivity to the anticancer drugs and irradiation. According to the IC(50) value, the sensitivity of 686LN-1-E1A cells increased approximately 8-fold to cisplatin, 20-fold to bleomycin, 10-fold to paclitaxel, 1-fold to irradiation compared with 686LN-1-vect cells. However, the sensitivity to 5-FU did not change. The cell cycle was dramatically arrested at G(2)/M phase in the 686LN-1-E1A cells. E1A gene remarkably suppressed the expression of HER-2/neu gene in 686LN-1-E1A cells. CONCLUSION: E1A gene can significantly inhibit the growth rate of lymph node metastasis cell line 686LN-1 of HNSCC. Moreover, it also slightly enhance the cell sensitivity to antitumor drugs and irradiation. These functions of E1A gene may be associated with its ability to suppress the HER-2/neu expression and to arrest the cell at G(2)/M phase.

[Effects of E1A gene on the growth and chemosensitivity of transplantation tumor of nude mice].

OBJECTIVE: To study the effects of E1A gene on the growth and chemosensitivity of transplantation tumor of nude mice of lymph node metastasis cell line (686LN-1) of human tongue squamous cell carcinoma. METHODS: 686LN-1, 686LN-1-vect and 686LN-1-E1A cells were transplanted into nude mice, then the time of tumor formation, growth rates and weight of tumor were observed. To study the effects of the E1A gene on bleomycin sensitivity in vivo, 686LN-1 cells were injected into nude mice. After tumor formed, bleomycin, E1A gene and E1A gene + bleomycin were given respectively as therapy. The tumor volume was calculated, and growth curve was plotted. Representative histological sections were taken from mice bearing transplantation tumor either treated or control groups, and expression of HER-2/neu was detected. RESULTS: In nude mice, the expression of E1A gene significantly suppressed the growth rates and elongated the time of tumor formation. Bleomycin or E1A Gene and E1A gene + bleomycin can suppress the growth rates of transplantation tumor of nude mice, the suppressed rates of tumor growth was 53.13%, 76.83% and 96.65%, respectively. The expression of E1A gene can significantly suppressed the expression of HER-2/neu gene in 686LN-1-E1A cells. CONCLUSION: E1A is able to significantly inhibit the growth rate of transplantation tumor of nude mice of lymph node metastasis cell line (686LN-1) of human tongue squamous cell carcinoma, and dramatically enhance the sensitivity of the cells to cytotoxic agents in vivo. Above of all functions of E1A gene may be related to that it suppressed the expression of HER-2/neu gene.