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Background: Increased CCKBR expression density or frequency has been reported in many neoplasms. Objective: We aimed to investigate whether CCKBR drives the growth of gastric cancer (GC) and its potential as a therapeutic target of immunotoxins. Methods: A lentiviral interference system was used to generate CCKBR-knockdown gastric cancer cells. Cell Counting Kit-8 and clonogenic assays were used to evaluate cell proliferation. Woundhealing and cell invasion assays were performed to evaluate cell mobility. Cell cycle was analyzed by flow cytometry. Tumor growth in vivo was investigated using a heterologous tumor transplantation model in nude mice. In addition, we generated the immunotoxin FQ17P and evaluated the combining capacity and tumor cytotoxicity of FQ17P in vitro. Results: Stable downregulation of CCKBR expression resulted in reduced proliferation, migration and invasion of BGC-823 and SGC-7901 cells. The impact of CCKBR on gastric cancer cells was further verified through CCKBR overexpression studies. Downregulation of CCKBR expression also inhibited the growth of gastric tumors in vivo. Furthermore, FQ17P killed CCKBR-overexpressing GC cells by specifically binding to CCKBR on the tumor cell surface. Conclusion: The CCKBR protein drives the growth, migration, and invasion of gastric cancer cells, and it might be a promising target for immunotoxin therapy based on its aberrant expression, functional binding interactions with gastrin, and subsequent internalization.

Background: Colorectal cancer (CRC) is a common digestive tract malignancy with high incidence and mortality rates. Radiotherapy is the most common anti-tumor therapeutic regime and is frequently used for treating CRC, especially rectal cancer. However, radiotherapy can lead to tumor resistance to treatment. While previous research on radiotherapy resistance in CRC has mostly focused on the tumor itself, recent advances, especially the emergence of immunotherapy, have led to a greater emphasis on the immune microenvironment of the tumor. Summary: This review summarizes the recent literature on the role of the tumor immune microenvironment in CRC resistance to radiotherapy and provides new ideas for future anti-tumor treatment strategies. Key messages: The proportion of immunosuppressive cells is greater than the numbers of cells associated with immune activation, leading to an overall state of immunosuppression; Both the tumor and immunosuppressive cells secrete increased amounts of immunosuppressive regulatory factors, reduce the recognition and presentation of tumor antigens, inhibit immune cell’s antitumor effect, and offset the non-targeted antitumor effect of radiotherapy.

Colon cancer liver metastasis accounts for the major cause of death of colon cancer patients. Previous study reported a carbon nanotubes (CNT)-conjugated CpG complex (CNT-CpG), which displayed a significant antitumor effect in gliomas. However, whether CNT-CpG could limit colon tumor growth and suppress the colon cancer liver metastasis has not been evaluated. In this study, we report CNT enhances CpG uptake in mouse colon cancer cells. Results demonstrated only CpG with CNT conjugation showed significant activation of NF-κB signal. Moreover, intratumorally delivery of CNT-CpG successfully suppressed local xenograft tumor growth and liver metastasis. CNT-CpG treatments cured 75% of mice and inhibited local tumor growth, significantly prolonged survival outcomes and limited liver metastatic tumor nodules from colon cancer cells. Using human colon cancer cell line, HCT116, we observed significantly inhibitory effects of CNT-CpG on cell growth, invasion and migration. Importantly, CNT-CpG treatment blocked the epithelial to mesenchymal transition (EMT). We compared the mRNA levels of EMT markers of colon cancer cells without or with CNT-CpG treatment from in-vitro and in-vivo models. Consistent results demonstrated expression of epithelial marker, E-cadherin was upregulated by CNT-CpG. In contrast, three mesenchymal markers, snail, fibronectin and vimentin were significantly suppressed by CNT-CpG treatment compared with control or free CpG. In summary, our data suggest CNT-CpG is an effective therapeutic approach against local colon tumor and their liver metastasis. This study presents the CNT-CpG complex as a promising therapeutic target for developing novel therapies against both local colon tumors and liver metastatic tumors.

Introduction Gastric cancer (GC) is one of the most malignancies leading to human mortality due to its development, progress, metastasis and poor prognosis, despite the development of remarkable chemotherapy and surgery. The 5-fluorouracil (5-Fu) is an effective anti-gastric cancer agent. However, a fraction of GC patients acquire 5-Fu chemoresistance. Methods In this study, the CagA protein was detected from CagA-positive gastric cancer patients by qRT-PCR and immunohistochemistry. The 5-Fu resistant gastric cancer cell line was generated from MKN45-CagA cells which was transfected with CagA overexpression vector. Cellular glucose metabolism was determined by measurements of glucose uptake, lactate product and glycolysis enzymes. Results We report that the Helicobacter pylori (H. pylori)-secreted Cytotoxin-associated gene A (CagA) oncoprotein is positively correlated with 5-Fu resistance of gastric cancer. From totally 72 CagA-positive gastric cancer patients, CagA high-expressed patients showed more resistance to 5-Fu than CagA low-expressed patients. Moreover, statistical analysis revealed that CagA mRNA and protein expressions were significantly upregulated in 5-Fu resistant gastric cancer patients. We observed that CagA protein is upregulated in 5-Fu resistant gastric cancer cells compared with sensitive cells. Interestingly, cellular glucose metabolism was upregulated; the glucose uptake and lactate production were significantly higher in 5-Fu resistant gastric cancer cells. The Akt phosphorylation and expressions of glycolysis key enzymes, Hexokinase 2 and LDHA, were significantly upregulated in 5-Fu resistant gastric cancer cells. On the other way, inhibition of glycolysis or Akt pathway effectively overcame 5-Fu resistance from both in vitro and in vivo models. Finally, we report that the combination of Akt or glycolysis inhibitor with 5-Fu could synergistically enhance the cytotoxicity of 5-Fu to CagA-overexpressed gastric cancer cells. Discussion In summary, our study demonstrated a CagA-Akt-glycolysis-5-Fu resistance axis, contributing to the development of new therapeutic agents against chemoresistant human gastric cancer.

Introduction The expression of MiR-135b-5p was up-regulated while Kruppel-like factor 4 (KLF4) expression was extremely low in human gastric carcinoma (GC) tissues. This study aimed to explore the role of miR-135b-5p in GC cells and its influence on various cell capacity and viability by targeting KLF4. Material and methods The dual-luciferase reporter assay was first performed and the target relationship between miR-135b-5p and KLF4 was confirmed. Then three GC cell lines and the human normal gastric epithelial cell line (GES1) were analyzed for the expression level of miR-135b-5p and KLF4 mRNA by RT-qPCR. The BGC-823 GC cell line was chosen for subsequent assays. Results The expression of miR-135b-5p and KLF4 was manipulated via transfection. The changes of proliferation, invasion, migration, viability, cycle and apoptosis of GC cells were evaluated by MTS, colony formation assay, transwell assay, wound healing assay and flow cytometry assay, respectively. Overexpression of MiR-135b-5p enhanced viability, proliferation, invasion and migration of GC cells, increased cell viability and reduced cell apoptosis. Replenishing of KLF4 functioned oppositely. Conclusions The inhibitory effects of ectopic KLF4 could be attenuated by co-transfection of miR-135b-5p. Collective data suggested that miR-135b-5p has a tumor-promoting role in GC cells via downregulating KLF4. Hence, inhibition of miR-135b-5p could be valuable for treatment of gastric cancer.

Effect of Runx3 gene on the cell proliferation and invasion of rectal cancer was investigated to explore potential new targets for targeted treatment of rectal cancer. The Runx3 overexpression group (OE group), blank plasmid control group, negative control and blank group of the rectal cancer HRC-9698 cell strain were set. The overexpressed Runx3 plasmid was transfected in OE group; the empty plasmid was transfected in blank plasmid control group; only liposome Lipofectamine was added to negative control group; only 1640 medium was used in blank group. RT-qPCR was used for detection of the mRNA expression of Runx3 in different groups; CCK-8 kit for detection of cell proliferation in different groups; Transwell chamber test for detection of cell strain invasion in different groups. The mRNA expression of Runx3 gene in OE group was the highest, significantly higher than that in blank plasmid control group, negative control and blank group (P

Background/Aims: The present study was aimed at examining Ezrin expression in human colorectal cancer (CRC) tissues and elucidating the influence of baicalein on the proliferation of HCT116 cells. Methods: The expression of Ezrin was determined by qRT-PCR and immunohistochemistry. HCT116 cells were divided into four groups－ baicalein groups with various concentrations, pcDNA3.1-Ezrin group, si-Ezrin group and dual inhibitory group (baicalein + si-Ezrin). CCK-8 assay and flow cytometry (FCM) were employed to assess cell proliferation and to detect the distribution of cell cycle respectively. The expression levels of Ezrin protein and cell cycle-associated proteins were detected by using western blot. The proliferation ability of CRC cells was also evaluated in vivo. Results: Ezrin expression in CRC tissues was observably higher than that in adjacent colorectal tissues. With drug concentration and action time of baicalein increasing, the cell propagation capacity of HCT116 cells was decreased and the cell cycle progression was arrested. Ezrin expression was inhibited by the administration of baicalein in a dose-dependent way. The levels of CyclinD1 and CDK4 were also significantly decreased, but the expression of P53 pathway proteins P53 and P21 was markedly upregulated. Conclusion: Baicalein repressed proliferation of human colorectal cancer cells HCT116 and blocked cell cycle through downregulating Ezrin and upregulating P53 pathway-related proteins.

This paper investigates protamine I (PRM1) expression and its effects on proliferation, invasion and migration of colon cancer cells as well as its function in clinical diagnosis and prognosis. Gene chips were used to screen differentially expressed genes. PRM1 expression was detected by Western blotting and quantitative real time-polymerase chain reaction (qRT-PCR). Hematoxylin and eosin (HE) staining and immunohistochemistry were utilized to compare the expression of PRM1 from multiple differentiation levels of colon cancer tissues. Cell viability, cell apoptosis and cell cycle were tested using the MTT assay and flow cytometry. Cell invasion and migration capability were tested using the Transwell assay and wound healing. In vivo effects of PRM1 on colon cancer were explored using a xenograft model. PRM1 expression in serum was detected by enzyme-linked immunosorbent assay (ELISA). The expression level of PRM1 was significantly higher in colon cancer tissues and the staining degree of PRM1 in poorly-differentiated was stronger. pcDNA3.1-PRM1 decreased cell apoptosis while it increased the proliferation, cell invasion and migration. The si-PRM1 group displayed an opposite tendency. The serum PRM1 level was significantly higher and could serve as a diagnostic biomarker for colon cancer.