Adjuvant therapy for resected colon cancer 2017, including the IDEA analysis

miR-23b-3p Inhibits the Oncogenicity of Colon Adenocarcinoma by Directly Targeting NFE2L3

Background and Aims

MicroR-23b-3p (miR-23b-3p) has been found to be abnormally expressed in a variety of malignant tumors and to play a role in tumor inhibition or promotion. However, the regulatory mechanism of miR-23b-3p in COAD remains unclear. The purpose of this study was to investigate the clinical significance of miR-23b-3p expression in COAD cells and to explore its role and regulatory mechanism in the growth of COAD.

Materials and Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure miR-23b-3p expression in COAD tissues and cell lines. After transfecting miR-23b-3p mimics into two human COAD cell lines (SW620 and LoVo), the cell counting kit-8 (CCK-8), colony formation, and 5-ethynyl-2′-deoxyuridine (EdU) assays were used to detect cell proliferation, the Transwell assay was used to measure cell migration and invasion capacity, and flow cytometry was used to evaluate cell apoptosis in vitro. In addition, a luciferase reporter assay was used to determine whether miR-23b-3p targets NFE2L3. The downstream regulatory mechanisms of miR-23b-3p action in COAD cells were also investigated. For in vivo tumorigenesis assay, COAD cells stably overexpressing miR-23b-3p were injected subcutaneously into the flank of nude mice to obtain tumors.

Results

Significantly decreased expression of miR-23b-3p was detected in COAD tissues and cell lines. Exogenous miR-23b-3p expression inhibited cell proliferation, migration, and invasion and promoted cell apoptosis of COAD cells in vitro. Nuclear factor erythroid 2 like 3 (NFE2L3) was identified as a direct target gene of miR-23b-3p. In addition, reintroduction of NFE2L3 partially abolished the anticancer effects of miR-23b-3p on COAD cells. Furthermore, miR-23b-3p overexpression hindered the growth of COAD cells in vivo.

Conclusion

miR-23b-3p inhibited the oncogenicity of COAD cells in vitro and in vivo by directly targeting NFE2L3, suggesting the importance of the miR-23b-3p/NFE2L3 pathway in the development of COAD.

LncRNA HCG11 promotes 5-FU resistance of colon cancer cells through reprogramming glucose metabolism by targeting the miR-144-3p-PDK4 axis

BACKGROUND

Colorectal cancer (CRC), one of the most common human malignancies, is a leading cause of the cancer-related mortality. 5-FU is a first-line chemotherapeutic agent against CRC. Although CRC patients responded to 5-FU therapy initially, a part of patients succumbed to CRC due to the acquired drug resistance. Thus, investigating molecular mechanisms underlying chemoresistance will contribute to developing novel strategies against colorectal cancer.

OBJECTIVE

Accumulation evidence revealed pivotal roles of long non-coding RNAs (lncRNAs) in tumorigenesis and chemoresistance of CRC. However, the precise roles and molecular mechanisms of lncRNA-HCG11 in CRC remain unclear. This study aimed to investigate the biological roles and underlying mechanisms of HCG11 as well as its molecular targets in regulating the cellular metabolism processes, which facilitate the chemoresistance of CRC.

METHODS AND RESULTS

This study uncovers that HCG11 was significantly upregulated in CRC tumors tissues and cell lines. Moreover, HCG11 was elevated in 5-FU resistant CRC tumors. Silencing HCG11 inhibited colon cancer cell proliferation, migration, invasion and glucose metabolism and sensitized CRC cells to 5-FU. In addition, we detected increased HCG11 expression level and glucose metabolism in the established 5-FU resistant CRC cell line (DLD-1 5-FU Res). Furthermore, microRNA-microArray, RNA pull-down and luciferase assays demonstrated that HCG11 inhibited miR-144-3p which displays suppressive roles in colon cancer via sponging it to form a ceRNA network. We identified pyruvate dehydrogenase kinase 4 (PDK4), which is a glucose metabolism key enzyme, was directly targeted by miR-144-3p in CRC cells. Rescue studies validated that the miR-144-3p-inhibited glucose metabolism and 5-FU sensitization were through targeting PDK4. Finally, restoration of miR-144-3p in HCG11-overexpressing DLD-1 5-FU resistant cells successfully overcame the HCG11-faciliated 5-FU resistance via targeting PDK4.

CONCLUSION

In summary, this study reveals critical roles and molecular mechanisms of the HCG11-mediated 5-FU resistance through modulating the miR-144-3p-PDK4-glucose metabolism pathway in CRC.

The prognostic impact of primary tumour location in patients with stage II and stage III colon cancer receiving adjuvant therapy. A GISCAD analysis from three large randomised trials

PURPOSE

Because the role of the primary tumour location in the adjuvant setting has not been clearly established in colon cancer, we analysed the clinical outcome according to the primary tumour location from three Italian trials assessing adjuvant therapy in colon cancer.

PATIENTS AND METHODS

Overall survival (OS) and disease-free survival (DFS) were assessed globally and in each trial, according to right-sided, transverse and left-sided primary colon cancer. Analysis was planned to provide overall and stage-specific results.

RESULTS

Individual data of 5239 patients were included in this analysis. The right-sided tumours were 1540 (29%), tumours originating in the transverse were 815 (16%) and left-sided tumours were 2884 (55%). At the multivariate analysis, DFS findings from the comparison of the right-sided versus left-sided tumours (hazard ratio [HR] = 1.00; 95% confidence interval [CI] = 0.89-1.14) were not statistically associated with clinical outcomes in the overall population. On the contrary, OS findings, from the comparison of the right-sided versus left-sided tumours, were significantly associated with outcomes (HR = 1.20; 95% CI = 1.04-1.39). In stage II patients, there was no difference in terms of DFS and OS among the three different tumour locations, whereas in stage III patients, the left-sided tumours showed an improved prognosis in terms of OS (HR: 1.36 95% CI = 1.14-1.62, p < 0.001).

CONCLUSION

This is the largest analysis demonstrating a prognostic effect of the tumour location on patients with colon cancer receiving adjuvant chemotherapy. Nevertheless, the effect is limited to OS in stage III colon cancer. In stage II tumours, the primary location has a lesser impact. The transverse tumours should be prognostically considered in between the right-sided and left-sided tumours.

TRIM2 is a novel promoter of human colorectal cancer

OBJECTIVES

The incidence of colorectal cancer (CRC) is increasing year by year and appears to be younger, due to the low early diagnosis rate and metastasis. It is difficult to remedy by conventional treatment. Here, we reported that tripartite motif containing protein 2 (TRIM2) could promote tumor growth, invasion and metastasis of CRC via a mechanism that involved EMT both in vitro and in vivo.

METHODS

First, we used immunohistochemistry to detect TRIM2 expression. Next, TCGA database was applied to the coorelation between TRIM2 and CRC progression. Then, the plasmids and lentivirus particles were used to manipulate TRIM2 expression in SW620 or HT29 cells. The assays of proliferation, adhesion, magration and invasion were employed to detect the migration and invasion ability of CRC cells. Finally, a tail injection of CRC cells was used to identify the role of TRIM2 in tumor metastasis.

RESULTS

TRIM2 expression was significantly higher in CRC tissues than in non-cancerous tissues and was significantly associated with some clinicopathological factors. Forced overexpression of TRIM2 promoted CRC cell proliferation, migration and invasion in vitro, while opposing results were observed when TRIM2 was depleted by short hairpin RNA. TRIM2 expression had reversely correlated with YAP signaling, which was a novel pathway way referred to tumorigenesis. Furthermore, animal metastasis models confirmed that the in vivo results were consistent with the outcomes in vitro. TRIM2 conducts its function during CRC cell metastasis by epithelial-mesenchymal transition (EMT). These results indicate that TRIM2 is a novel promoter of human colorectal cancer.

The Optimal Duration of Adjuvant Therapy for Stage III Colon Cancer: the European Perspective

OPINION STATEMENT

The International Duration Evaluation of Adjuvant Therapy (IDEA) collaboration was created to pool data from different studies worldwide in order to assess whether a shorter duration of adjuvant treatment in colon cancer could maintain the expected benefit while reducing toxicity. The results of the IDEA trials were clinically relevant. They confirmed a two- to sixfold reduction in neurotoxicity for the shorter duration across trials. Overall, the 3-year disease-free survival was very similar: only 0.9% lower for the 3 months group. However, the results were partially unexpected, because they revealed a difference among chemotherapy regimens (CAPOX better than FOLFOX) and risk groups within stage III. The similar outcome between 3 and 6 months of CAPOX coupled with the substantial reduction in toxicity makes us use the CAPOX regimen for 3 months for most stage III patients. An exception to this general rule is the patient with very high risk, i.e., either T4N1b-T4anyN2 or anyTN2b where we use 6 months of CAPOX. Our take from the trial results is also that FOLFOX should never be given for 3 months and preferably not used at all in the adjuvant setting. The conduction of the IDEA enterprise was truly global. The European contribution was major with three fourths of patients enrolled in the four European trials. Herein, we review the results of the "3 versus 6" trials and the literature regarding the interpretation of the collected data in Europe and in the rest of the world.