The Landmark Series: Chemotherapy for Non-Metastatic Colon Cancer

Hsa-miR-181a-2-3p inhibits the oncogenicity of colon cancer by directly targeting STING

OBJECTIVE

Colon cancer is a common malignant tumor of the gastrointestinal system, which is characterized by high morbidity and mortality. The purpose of this study was to analyze the expression and biological role of miR-181a-2-3p in colon cancer and to investigate the molecular mechanism of its regulatory effect on colon cancer through stimulator of interferon genes (STING).

METHODS

Real-time reverse transcription polymerase chain reaction (qRT-PCR) assay was used to detect the expression of miR-181a-2-3p in colon cancer cell lines and normal intestinal epithelial cells. After overexpression of miR-181a-2-3p in colon cancer cell lines SW480 and HT29, cells were examined by CCK8, Transwell, and flow cytometry assays for alterations in proliferation, migration, apoptosis, and cell cycle. Target genes of miR-181a-2-3p were predicted by bioinformatics and validated by dual luciferase assays. Rescue experiments were performed to explore the role of STING in the effect of miR-181a-2-3p. The effect of miR-181a-2-3p on colon cancer proliferation in vivo was validated by nude mouse tumorigenicity assay.

RESULTS

miR-181a-2-3p was lowly expressed in both colon cancer tissues and cell lines. Overexpression of miR-181a-2-3p led to reduced proliferation and migration, increased apoptosis, and altered cell cycle in colon cancer cell lines SW480 and HT29. STING was a target gene of miR-181a-2-3p. Increased STING expression partially counteracted the effect of overexpression of miR-181a-2-3p on colon cancer cell lines. miR-181a-2-3p also suppressed colon cancer proliferation in vivo.

CONCLUSION

miR-181a-2-3p inhibits the proliferation and oncogenicity of colon cancer, and its molecular mechanism could be inhibited by STING.

Arachidonic acid metabolism as a novel pathogenic factor in gastrointestinal cancers

Gastrointestinal (GI) cancers are a major global health burden, representing 20% of all cancer diagnoses and 22.5% of global cancer-related deaths. Their aggressive nature and resistance to treatment pose a significant challenge, with late-stage survival rates below 15% at five years. Therefore, there is an urgent need to delve deeper into the mechanisms of gastrointestinal cancer progression and optimize treatment strategies. Increasing evidence highlights the active involvement of abnormal arachidonic acid (AA) metabolism in various cancers. AA is a fatty acid mainly metabolized into diverse bioactive compounds by three enzymes: cyclooxygenase, lipoxygenase, and cytochrome P450 enzymes. Abnormal AA metabolism and altered levels of its metabolites may play a pivotal role in the development of GI cancers. However, the underlying mechanisms remain unclear. This review highlights a unique perspective by focusing on the abnormal metabolism of AA and its involvement in GI cancers. We summarize the latest advancements in understanding AA metabolism in GI cancers, outlining changes in AA levels and their potential role in liver, colorectal, pancreatic, esophageal, gastric, and gallbladder cancers. Moreover, we also explore the potential of targeting abnormal AA metabolism for future therapies, considering the current need to explore AA metabolism in GI cancers and outlining promising avenues for further research. Ultimately, such investigations aim to improve treatment options for patients with GI cancers and pave the way for better cancer management in this area.

Nanomedicine-based multimodal therapies: Recent progress and perspectives in colon cancer

Colon cancer has attracted much attention due to its annually increasing incidence. Conventional chemotherapeutic drugs are unsatisfactory in clinical application because of their lack of targeting and severe toxic side effects. In the past decade, nanomedicines with multimodal therapeutic strategies have shown potential for colon cancer because of their enhanced permeability and retention, high accumulation at tumor sites, co-loading with different drugs, and comb-ination of various therapies. This review summarizes the advances in research on various nanomedicine-based therapeutic strategies including chemotherapy, radiotherapy, phototherapy (photothermal therapy and photodynamic therapy), chemodynamic therapy, gas therapy, and immunotherapy. Additionally, the therapeutic mechanisms, limitations, improvements, and future of the above therapies are discussed.

Deficient mismatch repair/microsatellite unstable colorectal cancer: Diagnosis, prognosis and treatment

Microsatellite unstable (MSI) colorectal cancers (CRCs) are due to DNA mismatch repair (MMR) deficiency and occurs in15% of non-metastatic diseases and 5% in the metastatic setting. Nearly 30% of MSI CRCs occur in a context of constitutional mutation of the MMR system (Lynch syndrome). Others are sporadic cancers linked to a hypermethylation of the MLH-1 promoter. The pathogenic alterations of MMR genes lead to the accumulation of frequent somatic mutational events and these tumours arbour a high antigen burden and are highly infiltrated with cytotoxic T-cell lymphocytes. Microsatellite instability/DNA mismatch repair deficiency (MSI/dMMR) status has prognostic and predictive implications in non-metastatic and metastatic CRCs. The prognostic value of MSI status in non-metastatic CRCs has been studied extensively, yet the data are more limited for its predictive value in terms of adjuvant chemotherapy efficacy. In both cases (metastatic and non-metastatic settings) treatment with immune check-point inhibitors (ICIs) have shown a remarkable effectiveness in the context of MSI/dMMR status. Indeed, recent data from prospective cohorts and randomised trials have shown a dramatical improvement of survival with immunotherapy (programmed death-ligand 1 [PD-(L)1]   cytotoxic T-lymphocyte-associated antigen 4 [CTLA-4] blockage) in metastatic or non-metastatic MSI/dMMR CRC. In this review we report and discuss how and for whom to test for the MSI/dMMR phenotype, as well as the prognostic value of this phenotype and the new treatment recommendations options for this unique CRC population. Despite their efficacy, primary and secondary resistance to immune checkpoint inhibitors (ICIs) are observed in more than 50% MSI-H/dMMR CRC patients and in the future how to identify these patients and to overcome resistance will be an important challenge.

Polyphyllin I Promotes Autophagic Cell Death and Apoptosis of Colon Cancer Cells via the ROS-Inhibited AKT/mTOR Pathway

Colon cancer is a common malignant tumor of the digestive tract, and it is considered among the biggest killers. Scientific and reasonable treatments can effectively improve the survival rate of patients if performed in the early stages. Polyphyllin I (PPI), a pennogenyl saponin isolated from Paris polyphylla var. yunnanensis, has exhibited strong anti-cancer activities in previous studies. Here, we report that PPI exhibits a cytotoxic effect on colon cancer cells. PPI suppressed cell viability and induced autophagic cell death in SW480 cells after 12 and 24 h, with the IC50 values 4.9 ± 0.1 μmol/L and 3.5 ± 0.2 μmol/L, respectively. Furthermore, we found PPI induced time-concentration-dependent autophagy and apoptosis in SW480 cells. In addition, down-regulated AKT/mTOR activity was found in PPI-treated SW480 cells. Increased levels of ROS might link to autophagy and apoptosis because reducing the level of ROS by antioxidant N-acetylcysteine (NAC) treatment mitigated PPI-induced autophagy and apoptosis. Although we did not know the molecular mechanism of how PPI induced ROS production, this is the first study to show that PPI induces ROS production and down-regulates the AKT/mTOR pathway, which subsequently promotes the autophagic cell death and apoptosis of colon cancer cells. This present study reports PPI as a potential therapeutic agent for colon cancer and reveals its underlying mechanisms of action.

Combination of Geriatric Nutritional Risk Index and Carcinoembryonic Antigen to Predict the Survival of Patients With Colorectal Cancer

Background

This study explored the value of the combination of Geriatric Nutritional Risk Index (GNRI) and carcinoembryonic antigen (CEA) for the prognosis assessment of CRC patients.

Methods

This study retrospectively enrolled 1,014 CRC patients who underwent surgery between 2012 and 2014. Kaplan-Meier and log-rank tests were used to compare survival differences. Cox proportional hazards regression analysis was used to assess risk factors associated with progression-free survival (PFS) and overall survival (OS). Nomograms were constructed to predict the prognosis of CRC patients. Randomized internal validation was used to confirm the predictive accuracy of the prognostic nomograms.

Results

The GNRI-CEA score was established by combining GNRI and CEA. Compared with patients with normal GNRI-CEA scores, patients with mild/moderate/severe GNRI-CEA scores had significantly lower survival (PFS, 68.99% vs. 57.75% vs. 41.34% vs. 31.36%, p < 0.001; OS, 68.99% vs. 57.75% vs. 41.34% vs. 31.36%, p < 0.001). The GNRI-CEA score is an independent factor predicting the prognosis of CRC patients. The risk of death was twofold higher in patients with low GNRI and high CEA than in those with both normal GNRI and CEA [PFS, hazard ratio (HR), 2.339; 95% confidence interval (CI), 1.656-3.303; p < 0.001; OS, HR, 2.340; 95% CI, 1.645-3.329; p < 0.001]. Prognostic nomograms had good resolution and accuracy in predicting 1-5 year PFS and OS. Randomized internal validation showed that the nomograms were reliable.

Conclusion

The combination of GNRI and CEA can effectively stratify the prognosis of CRC patients. The nomogram established based on the two indices can provide a personalized reference for prognostic assessment and clinical decision-making for CRC patients.

Prognostic Value of Combined Preoperative Carcinoembryonic Antigen and Prognostic Nutritional Index in Patients With Stage II-III Colon Cancer

Background: Tumor status can affect patient prognosis. Prognostic nutritional index (PNI), as a nutritional indicator, is closely related to the prognosis of cancer. However, few studies have examined the combined prognostic value of CEA and PNI in patients. This study investigated the relationship between CEA/PNI and prognosis of colon cancer patients.

Methods: A total of 513 patients with stage II–III colon cancer who underwent curative resection at two medical centers from 2009 to 2019 were included. Clinicopathological factors were assessed and overall survival (OS) was assessed in a cohort of 413 patients. Multivariate analysis was used to identify independent prognostic variables to construct histograms predicting 1-year and 3-year OS. Data from 100 independent patients in the validation group was used to validate the prognostic model.

Results: The median OS time was 33.6 months, and mortality was observed in 54 patients. Multivariate analysis revealed that preoperative CEA/PNI, lymph node metastasis, peripheral nerve invasion, operation mode, and postoperative chemotherapy were independent factors for prognosis evaluation and thus were utilized to develop the nomogram. The C-index was 0.788 in the learning set and 0.836 in the validation set. The calibration curves reached favorable consensus among the 1-, 3-year OS prediction and actual observation.

Conclusion: The combined use of CEA and PNI is an independent prognostic factor and thus can serve as a basis for a model to predict the prognosis of patients with stage II–III colon cancer.