circSFMBT1 promotes pancreatic cancer growth and metastasis via targeting miR-330-5p/PAK1 axis.

Pancreatic cancer (PC) is one of the most common and lethal cancers that affects millions of people around the world. The prognosis of PC is poor with very limited effective treatments. Here, we fully investigated the function and underlying mechanism of circSFMBT1 (hsa_circ_0066147) in PC. Real-time quantitative PCR, Western blotting, and immunohistochemistry were used to examine levels of circSFMBT1, miR-330-5p, PAK1 (p21-activated kinase 1), or proliferation/metastasis-related proteins. Colony formation assay, flow cytometry, and transwell assay detected the roles of circSFMBT1 and miR-330-5p in cell apoptosis, proliferation, migration, and invasion of PC cells, respectively. Dual luciferase assay and RNA immunoprecipitation were used to validate the interactions of circSFMBT1/miR-330-5p and miR-330-5p/PAK1. Fluorescence in situ hybridization was performed to examine the subcellular localization of circSFMBT1 and miR-330-5p. Subcutaneous tumor growth was monitored in nude mice and in vivo metastasis was examined as well following injection of PC cells into the tail vein. This study demonstrated that circSFMBT1 and PAK1 were up-regulated in PC tissues and cells, while miR-330-5p was down-regulated. circSFMBT1 directly bound miR-330-5p and inhibited its expression. In addition, circSFMBT1 promoted proliferation, migration, and invasion of PC cells through up-regulating proliferation-related proteins and down-regulating apoptosis-related proteins via miR-330-5p. miR-330-5p directly bound PAK1 mRNA and suppressed proliferation, migration, invasion, and epithelial-mesenchymal transition process via targeting PAK1 in PC cells. Further, knockdown circSFMBT1 increased miR-330-5p level, but decreased PAK1 expression and repressed tumor growth and metastasis in vivo. Taken together, circSFMBT1 promotes proliferation and metastasis of PC via regulating miR-330-5p/PAK1 pathway as a miR-330-5p sponge.

Inhibitory Effect and Molecular Mechanism of the New Phorphyrin-Based HCE6 Photosensitizer on the Activity of MKN45 Human Gastric Cancer Cells.

Gastric cancer is the fourth most common cancer worldwide and the third most common in Asia, with a high mortality. Photodynamic therapy (PDT) is a new treatment for cancer. With advantages of minimum invasiveness, small adverse side effects and high selectivity, PDT can be used as palliative treatment for patients with advanced gastric cancer. YLG I, also known as 2-(1 hexyloxyethyl)-2-devinyl porphin e6 trisodium salt (HCE6), is a recently developed photosensitizer. A previous study showed that HCE6 significantly inhibited the growth of QBC939 human cholangiocarcinoma cells. However, the effects and mechanisms of HCE6 on gastric cancer cell suppression are not known. In this study, we investigated the effects of HCE6 on the human gastric cancer cell line MKN45 and found that at the concentration of 2.0 mg/L, HCE6 almost completely killed MKN45 cells at a light intensity of 3.6 J/cm². RNAseq results confirmed that mitochondria and endoplasmic reticulum (ER)-mediated apoptosis was involved in the effects of HCE6 on cell death, and we also found that HCE6 induced chromosome conformational changes in the early phase of apoptosis. The results of our study help elucidate the molecular mechanisms underlying HCE6-mediated inhibition of gastric cancer cell growth and provide a theoretical basis and molecular targets for the treatment of gastric cancer.

Photodynamic therapy as salvage therapy for residual microscopic cancer after ultra-low anterior resection: A case report.

BACKGROUND: The rate of positive resection margins (R1) in patients with low rectal cancer is substantial. Recommended remedies such as extended resection or chemoradiotherapy have their own serious drawbacks. It has been reported that photodynamic therapy (PDT) as a remedial treatment for esophageal cancer. Colorectal cancer and esophageal cancer has many similarities, however, PDT as a salvage therapy for rectal cancer is rare. CASE SUMMARY: Here, we describe a 56-year-old man who was admitted to the hospital due to a 6-mo history of hemafecia, which had been aggravated for 1 mo. Colonoscopy revealed a 3 cm × 4 cm ulcerated mass in the rectum 4 cm from the anus. Preoperative pathological examination showed villous adenoma, moderate-to-high-grade dysplasia, good differentiation, and invasion of the mucosal muscle. The patient had R1 after ultra-low anterior resection, but he refused extended resection and experienced severe liver function impairment after 3 cycles of chemotherapy. Ultimately, the patient underwent PDT to remove R1. After five years of follow-up, there was no liver function impairment, recurrence, metastasis, sexual dysfunction, or abnormal defecation function. CONCLUSION: This is the first case worldwide in which R1 of rectal cancer were successfully treated by PDT.

Regulatory roles of microRNA-708 and microRNA-31 in proliferation, apoptosis and invasion of colorectal cancer cells.

MicroRNAs (miRs) function as key regulators of gene expression and their deregulation is associated with the carcinogenesis of various cancers. In the present study, the aim was to validate the potential roles and regulatory mechanisms of miR-708 and miR-31 in colorectal cancer (CRC) cells. miR-708 and miR-31 were found to be highly expressed in five CRC tissue samples. Functional studies showed that the inhibition of miR-708 and miR-31 inhibited cell proliferation and invasion, however, promoted apoptosis in vitro. Subsequently, it was identified that miR-708 and miR-31 directly target cyclin-dependent kinase inhibitor 2B (CDKN2B) by binding to the 3' untranslated region, which suppresses the CDKN2B protein levels. In addition, the CDKN2B protein levels were significantly reduced when there was high miR-708 and miR-31 expression in the CRC tissue samples. The results indicate that miR-31 and miR-708 function in an oncogenic manner in CRC development, and inhibition of the two miRs may be used as a therapeutic strategy for patients with CRC.

Meta-analysis of the aldehyde dehydrogenases-2 (ALDH2) Glu487Lys polymorphism and colorectal cancer risk.

A number of studies have explored the association of the aldehyde dehydrogenases-2 (ALDH2) Glu487Lys polymorphism and risk of colorectal cancer; however, the results are inconsistent. We performed this meta-analysis to clarify this issue using all the available evidence. Relevant studies were retrieved by searching PubMed. Eleven case-control studies were included in the meta-analysis, representing 2909 cases and 4903 controls. The pooled results based on all included studies showed a decreased colorectal cancer risk in the analysis of the GA genotype vs. the GG genotype (OR = 0.81, 95%CI = 0.68-0.98, p = 0.03) and in the dominant genetic model analysis (OR = 0.81, 95%CI = 0.67-0.98, p = 0.03). However, there was no statistical difference in the AA vs. GG analysis (OR = 0.74, 95%CI = 0.52-1.06,p = 0.11) and the recessive genetic model analysis (OR = 0.86, 95%CI = 0.69-1.07, p = 0.17). Cumulative meta-analysis based on publication time confirmed these findings. Patients with colorectal cancer had a higher frequency of the GG genotype (OR = 1.10, 95% CI = 1.02-1.20, p = 0.02) and a lower frequency of the GA genotype (OR = 0.89, 95%CI = 0.81-0.98, p = 0.02) comparing with control population. Our results suggested that the ALDH2 Glu487Lys polymorphism may be associated with a decreased risk of colorectal cancer.

An updated meta-analysis of the p53 codon 72 polymorphism and gastric cancer risk.

To investigate the association between p53 codon 72 polymorphisms and gastric cancer risk, a meta-analysis published in 2007 was updated with new data. Relevant literature was retrieved by searching PubMed and statistical analysis conducted using Review Manager software. Twenty-eight case-control studies were included in this meta-analysis, with 6,859 cases and 9,277 controls. The pooled results for all included studies showed that patients with gastric cancer had a borderline lower frequency of the Arg/Arg phenotype (odds ratio (OR) = 0.91, 95 % CI = 0.83-1.00, p = 0.04). When stratified for race, the difference in Arg/Arg frequency was significant among Asians (OR = 0.87, 95 % CI = 0.78-0.97, p = 0.01). On stratifying the various studies we found that, among Asians: (i) patients with cardial gastric cancer had a significantly higher frequency of the Pro/Pro genotype (OR = 1.35, 95 % CI = 1.03-1.77, p = 0.04) than those with non-cardial gastric cancer; (ii) patients with advanced (stage III/IV) gastric cancer had a significantly higher frequency of Arg/Arg (OR = 1.30, 95 % CI = 1.06-1.61, p = 0.01) than those with early (stage I/II) cancer; and (iii) patients with metastasis had a significantly higher frequency of Pro/Pro (OR = 3.31, 95 % CI = 1.31-8.41) than those without metastasis. Our study suggests that, among Asians, the p53 codon 72 Arg/Arg genotype is associated with a modestly decreased risk of gastric cancer, and that this difference in genotype distribution may be associated with cancer stage, location, differentiation and metastasis.

[Laparoscopic partial gastrectomy: Analysis of 18 procedures].

OBJECTIVE: To explore the laparoscopic partial gastrectomy and the indications. METHODS: Eighteen patients who underwent laparoscopic partial gastrectomy from August 2005 to May 2006 were analyzed retrospectively. RESULTS: Sixteen patients (including 6 with gastric cancer, 9 with duodenal ulcer, and 1 with gastric multiple polyps) underwent laparoscopic partial gastrectomy. The other two patients underwent an open surgical procedure (1 patient with the tumor size large than 6 cm, and the other patient with bleeding after loosening one clip). The rate of intraoperative subcutaneous emphysema was 5.88% (1/17), and no death occurred. The operation time was (285+/-30)min on average, the estimated blood loss was (130+/-50)mL, and the hospitalization was (11+/-4)d. One case of obstruction of distal loop happened after the surgery, and the rate was 6.25% (1/16). The patients were followed up for 1 approximately 9 months postoperatively. Trocar puncture-site metastases occurred in one patient. CONCLUSION: Laparoscopic partial gastrectomy is safe and feasible with skillful laparoscopic technique and with restricted indications, and the surgical outcome may be similar to that of the open surgery.