MUC2 protein expression status is useful in assessing the effects of hyperthermic intraperitoneal chemotherapy for peritoneal dissemination of colon cancer

Upregulated MUC2 Is an Unfavorable Prognostic Indicator for Rectal Cancer Patients Undergoing Preoperative CCRT

For locally advanced rectal cancer patients, introducing neoadjuvant concurrent chemoradiotherapy (CCRT) before radical resection allows tumor downstaging and increases the rate of anus retention. Since accurate staging before surgery and sensitivity prediction to CCRT remain challenging, a more precise genetic biomarker is urgently needed to enhance the management of such situations. The epithelial mucous barrier can protect the gut lumen, but aberrant mucin synthesis may defend against drug penetration. In this study, we focused on genes related to maintenance of gastrointestinal epithelium (GO: 0030277) and identified mucin 2 (MUC2) as the most significantly upregulated gene correlated with CCRT resistance through a public rectal cancer transcriptome dataset (GSE35452). We retrieved 172 records of rectal cancer patients undergoing CCRT accompanied by radical resection from our biobank. We also assessed the expression level of MUC2 using immunohistochemistry. The results showed that upregulated MUC2 immunoexpression was considerably correlated with the pre-CCRT and post-CCRT positive nodal status (p = 0.001 and p < 0.001), advanced pre-CCRT and post-CCRT tumor status (p = 0.022 and p < 0.001), vascular invasion (p = 0.015), and no or little response to CCRT (p = 0.006). Upregulated MUC2 immunoexpression was adversely prognostic for all three endpoints, disease-specific survival (DSS), local recurrence-free survival (LRFS), and metastasis-free survival (MeFS) (all p < 0.0001), at the univariate level. Moreover, upregulated MUC2 immunoexpression was an independent prognostic factor for worse DSS (p < 0.001), LRFS (p = 0.008), and MeFS (p = 0.003) at the multivariate level. Collectively, these results imply that upregulated MUC2 expression is characterized by a more advanced clinical course and treatment resistance in rectal cancer patients undergoing CCRT, revealing the potential prognostic utility of MUC2 expression.

Prognostic Value of MUC2 Expression in Colorectal Cancer: A Systematic Review and Meta-Analysis

Background

The reliability of MUC2 as a prognostic marker in colorectal cancer (CRC) is controversial. This study evaluated the association between MUC2 expression levels in CRC tissues and prognosis.

Methods

The PubMed, Web of Science, Embase, Cochrane Library, China Biology Medicine disc (CBMdisc), Wanfang Database, and China National Knowledge Infrastructure (CNKI) databases were searched to identify studies exploring the relationship between MUC2 expression in CRC tissues and overall survival (OS). Pooled hazard ratios (HRs) and risk ratios (RRs) with 95% confidence intervals (CIs) were used to evaluate the associations between MUC2 expression levels and prognosis and MUC2 expression levels and CRC clinicopathological characteristics, respectively.

Results

The meta-analysis included 11 studies (2619 patients). Low MUC2 expression level was significantly associated with poor OS (HR, 1.67; 95% CI, 1.43–1.94; P < 0.00001) and disease-free survival (DFS)/recurrence-free survival (RFS) (HR, 1.60; 95% CI, 1.21–2.12; P = 0.001) in patients with CRC. Low MUC2 expression level was associated with advanced TNM stage (RR, 1.42; 95% CI, 1.26–1.60; P < 0.00001), lymph node metastasis (RR, 1.41; 95% CI, 1.25–1.60; P < 0.00001), lymphatic invasion (RR,1.64; 95% CI, 1.26–2.12; P = 0.0002), rectal tumor site (RR, 1.26; 95% CI, 1.09–1.46; P = 0.001), and large tumor size (RR,1.32; 95% CI, 1.02–1.70; P = 0.03). There were no associations between low MUC2 expression level and gender, histological grade, depth of invasion, and distant metastasis.

Conclusion

The low levels of MUC2 in CRC tissues are poor prognostic factor independent of stage or other well-recognized markers of later-stage disease. Large well-designed cohort studies are required to validate MUC2 as a biomarker for poor prognosis in CRC.

Overview of the optimal perioperative intraperitoneal chemotherapy regimens used in current clinical practice

Peritoneal surface malignancy (PSM) is a common manifestation of digestive and gynecologic malignancies alike. At present, patients with isolated PSM are treated with a combination therapy of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). The combination of CRS and intraperitoneal (IP) chemotherapy should now be considered standard of care for PSM from appendiceal epithelial cancers, colorectal cancer and peritoneal mesothelioma. Although there is a near universal standardization regarding the CRS, we are still lacking a much-needed standardization among the various IP chemotherapy treatment modalities used today in clinical practice. Pharmacologic evidence should be generated to answer important questions raised by the myriad of variables associated with IP chemotherapy.

Hyperthermic intraperitoneal chemotherapy with mitomycin C and 5-fluorouracil in patients at high risk of peritoneal metastasis from colorectal cancer: A preliminary clinical study

Although hyperthermic intraperitoneal chemotherapy (HIPEC) has been extensively used to treat patients with peritoneal metastases (PM) from colorectal cancer (CRC), a standard protocol has not yet been established. The aim of this preliminary clinical study was to confirm in vitro the efficacy of mitomycin C combined with 5-fluorouracil (MMC-5FU) under hyperthermic conditions in CRC and investigate the pharmacokinetics and feasibility of HIPEC with MMC-5FU for patients at high risk of PM from CRC. To simulate HIPEC in vitro, we used the collagen gel droplet-embedded culture drug sensitivity test with the HCT166 colorectal cell line to assess the antitumor efficacy of MMC and 5FU as single-agent and combination treatments following incubation with HCT116 cells for 30 min at either 37 or 42°C. In addition, five patients at high risk of PM from CRC underwent surgical tumor resection followed by HIPEC with MMC-5FU. Our results demonstrated that the combined administration of MMC-5FU suppressed tumor cell proliferation more efficiently compared to either agent used alone. In addition, hyperthermia at 42°C significantly enhanced drug sensitivity. During the clinical application of HIPEC with MMC-5FU, no grade 4 hematological toxicities or surgical adverse events were recorded. In addition, there was no evidence of peritoneal recurrence during a median observational period of 38 months. Of note, two patients with positive intraoperative peritoneal cytology at the first surgery developed no peritoneal recurrence and exhibited negative peritoneal cytology at the second surgery. In conclusion, HIPEC using MMC-5FU was shown to be a feasible therapeutic option, with an acceptable toxicity profile, for patients at high risk of PM from CRC. Therefore, HIPEC with MMC-5FU may be a promising novel therapeutic option for such patients, which merits further verification of its safety and efficacy in large-scale clinical trials.

Polysaccharide K suppresses angiogenesis in colon cancer cells

The protein-bound polysaccharide K (PSK) is used as a non-specific immunotherapeutic agent for the treatment of colon cancer. Little research, however, has been conducted on its association with angiogenesis, which is a prognostic factor markedly correlated with hematogenous metastases. We therefore decided to investigate the action of PSK on angiogenic growth factors, angiogenesis inhibitors and angiogenesis in colon cancer cells. Reverse transcription-polymerase chain reaction (RT-PCR) was used to investigate changes in HIF-1α mRNA expression. PCR array was used to investigate changes in angiogenic growth factors and angiogenesis inhibitors, as well as the expression of related genes. Colon cancer cells were cultured with or without PSK for 48 h. The following day, cells were cultured for two days at 37°C in new complete media. The resulting culture medium was placed in the chamber of a tube formation system in order to investigate tube formation. Investigation of HIF-1α mRNA expression in colon cancer cell lines and in cells cultured under identical conditions with added PSK revealed a significant decrease in expression, as well as a decrease in angiogenic growth factors and related genes in PSK-treated colon cancer cell lines. By contrast, levels of angiogenesis inhibitors and related genes were higher in the PSK-treated colon cancer cell lines. Investigation of tube formation revealed that elongation was inhibited in the medium of the PSK-treated colon cancer cell lines in comparison to the medium of the non-treated colon cancer cell lines. PSK suppresses angiogenic growth factors and related genes, enhances angiogenesis inhibitors and related genes and ultimately suppresses angiogenesis in colon cancer cells.