Ying Yuan

Identification of MST1 as a potential early detection biomarker for colorectal cancer through a proteomic approach

Colorectal cancer (CRC) is a common malignant neoplasm worldwide. It is important to identify new biomarkers for the early detection of CRC. In this study, magnetic beads and the Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) platform were used to analyse CRC and healthy control (HC) serum samples. The CRC diagnosis pattern was established to have a specificity of 94.7% and sensitivity of 92.3% in a blind test. The candidate biomarker serine/threonine kinase 4 (STK4, also known as MST1) was identified by Tandem mass spectrometry (MS/MS) and verified with western blotting and enzyme-linked immunosorbent assay (ELISA). The results indicated that there was a higher concentration of MST1 in HC subjects than stage I CRC patients for the early detection of CRC and a lower concentration in stage IV patients than in other CRC patients. The sensitivity and specificity of MST1 combined with carcinoembryonic antigen (CEA) and faecal occult blood test (FOBT) in diagnosis of colorectal cancer were 92.3% and 100%, respectively. Additionally, low MST1 expression was associated with the poor prognosis. These results illustrate that MST1 is a potential biomarker for early detection, prognosis and prediction of distant metastasis of CRC.

CLCA1 suppresses colorectal cancer aggressiveness via inhibition of the Wnt/beta-catenin signaling pathway

BackgroundChloride channel accessory 1 (CLCA1) belongs to the calcium-sensitive chloride conductance protein family, which is mainly expressed in the colon, small intestine and appendix. This study was conducted to investigate the functions and mechanisms of CLCA1 in colorectal cancer (CRC).MethodsThe CLCA1 protein expression level in CRC patients was evaluated by enzyme-linked immunosorbent assay (ELISA), immunohistochemistry (IHC), and western blotting analysis. Using CRISPR/Cas9 technology, CLCA1-upregulated (CLCA1-ACT) and CLCA1-knockout cells (CLCA1-KO), as well as their respective negative controls (CLCA1-ACT-NC and CLCA1-KO-NC), were constructed from the SW620 cell line. Cell growth and metastatic ability were assessed both in vitro and in vivo. The association of CLCA1 with epithelial-mesenchymal transition (EMT) and other signaling pathways was determined by western blotting assays.ResultsThe expression level of CLCA1 in CRC tissues was significantly decreased compared with that in adjacent normal tissue (P<xa00.05). Meanwhile, the serum concentration of CLCA1 in CRC patients was also significantly lower when compared with that of healthy controls (1.48u2009±u20091.06xa0ng/mL vs 1.06u2009±u20090.73xa0ng/mL, Pu2009=u20090.0018). In addition, CLCA1 serum concentration and mRNA expression level in CRC tissues were inversely correlated with CRC metastasis and tumor stage. Upregulated CLCA1 suppressed CRC growth and metastasis in vitro and in vivo, whereas inhibition of CLCA1 led to the opposite results. Increased expression levels of CLCA1 could repress Wnt signaling and the EMT process in CRC cells.ConclusionsOur findings suggest that increased expression levels of CLCA1 can suppress CRC aggressiveness. CLCA1 functions as a tumor suppressor possibly via inhibition of the Wnt/beta-catenin signaling pathway and the EMT process.

Competing nomograms help in the selection of elderly patients with colon cancer for adjuvant chemotherapy

PurposeThe extent to whichu2009≥u200970xa0year patients with colon cancer benefit from adjuvant chemotherapy in the presence of competing risks remains controversial.Methods18,937 patientsu2009≥u200970xa0years with high-risk stage II and stage III colon cancer were retrospectively reviewed from SEER database. Propensity score matching (PSM) was used to adjust for potential baseline confounding. The nomograms were developed based on the competing model to describe the individual probability of colon cancer-specific death (CCSD) and non-CCSD. The subpopulation treatment-effect pattern plot (STEPP) was used to estimate the treatment-effect heterogeneity.ResultsIn the high-risk stage II subgroup, compared to the non-recipients, the hazard ratios (HR) of overall mortality for recipients were 0.83 (Pu2009=u20090.001). The subdistribution hazard ratio (SHR) of CCSD for receipts was 1.22 (Pu2009=u20090.021). The SHR of non-CCSD was 0.63 (Pu2009<u20090.001). In the stage III subgroup, compared to non-recipients, the HR of the overall mortality for the recipients was 0.62 (Pu2009<u20090.001). The SHR of CCSD was 0.77 (Pu2009<u20090.001). The SHR of non-CCSD was 0.58 (Pu2009<u20090.001). The chemotherapy efficacy differed significantly by risk score of non-CCSD (non-CCSD-RS) (Pu2009<u20090.001). Recipients with high non-CCSD-RS had a rate of CCSD comparative to that of non-recipients (SHR 0.90, Pu2009=u20090.150) in the stage III subgroup.ConclusionsA survival analysis based on the overall mortality did not correctly interpret the effect of chemotherapy. Adjuvant chemotherapy did not provide an additional benefit to patients with high-risk stage II or patients with stage III at high risk of non-cancer death.

A Novel and Reliable Method to Detect Microsatellite Instability in Colorectal Cancer by Next-Generation Sequencing

Two types of molecular tests have been established to assess the deficiency of the DNA mismatch repair (MMR) system: microsatellite instability (MSI) and immunohistochemical (IHC) analysis. We have developed a reliable method to analyze the MSI status by next-generation sequencing (NGS) based on read-count distribution. A total of 91 patients with primary colorectal cancer were recruited. These patients included 54 cases with loss of expression of any MMR protein in IHC, suggesting deficient MMR (dMMR), and 37 cases of colorectal cancer with staining of all four MMR proteins in IHC, suggesting proficient MMR in the sample after surgery. DNA was extracted from paired tumor-normal tissue for MSI detection by both the ColonCore NGS panel and PCR. The sequencing data from the NGS panel was processed using various MSI detection pipelines for a comparison with the ColonCore panel. Using the MSI-PCR test as the gold standard, MSI-ColonCore achieved 97.9% sensitivity (47 of 48) and 100% specificity (37 of 37) for the detection of MSI status. MSI-ColonCore also showed more efficient and robust performance compared with other NGS-based MSI detection algorithms. The concordance rate was 92.3% between MSI-ColonCore and IHC testing, and 93.4% between MSI-PCR and IHC testing. These results suggest that MSI-ColonCore is a reliable and robust method for MSI status detection by NGS based on read-count distribution.

Efficacy of vemurafenib in a heavy smoker with BRAF-mutated lung adenocarcinoma: A case report and literature review

At present, research on BRAF gene mutations appears to be mainly focused on melanoma rather than non-small-cell lung cancer (NSCLC). We herein describe the case of a patient with BRAF V600E-mutated advanced NSCLC, whose symptoms were relieved and computed tomography imaging revealed partial response to vemurafenib following failure of chemotherapy. This case demonstrates the promising prospects of BRAF inhibitor treatment in patients with BRAF-mutated NSCLC. Targeted therapies have significantly modified the treatment of NSCLC. However, tumor tissue is frequently hard to obtain, whereas the coincidence rate of gene mutations between the plasma and tumor tissue is 60-80%. Therefore, in cases where tumor tissue is difficult to obtain, plasma next-generation sequencing may be used to detect gene mutations, which can overcome the limitations of gene detection. Furthermore, due to the tumor heterogeneity, different patients exhibit different gene mutation abundance. Research has demonstrated that mutation abundance is associated with the therapeutic efficacy of epidermal growth factor receptor-tyrosine kinase inhibitors. However, the association between BRAF mutation abundance and the therapeutic effect of BRAF inhibitors requires further verification.

Afatinib treatment for her-2 amplified metastatic colorectal cancer based on patient-derived xenograft models and next generation sequencing

ABSTRACT Background: Substantial progress has been made in metastatic colorectal cancer (mCRC) treatment, but there is still a fraction of patients cannot find any effective therapeutic strategy after guideline-recommended standard chemotherapy and molecular targeted therapy. Case presentation: Here we present a KRAS/NRAS/BRAF wild-type mCRC patient who has been previously treated with FOLFIRI (fluorouracil, leucovorin, and irinotecan), XELOX (capecitabine and oxaliplatin), cetuximab and bevacizumab, and then received the next generation sequencing (NGS) and whose metastatic subcutaneous nodule was resected to generate patient-derived xenograft (PDX) models. The NGS revealed HER-2 amplification as well as an activating mutation S310F and PDX models tested several drugs finding that afatinib was the optimal agent with notable efficacy and well tolerance among 6 regimens. Therefore, this patient started to take afatinib orally and achieved 3 months progression-free survival (PFS) and relief of clinical symptoms without severe adverse effects. Conclusions: NGS and PDX models have great significance for precision and individualized medicine in the mCRC treatment, especially for patients whose diseases have been progressed after multiline standard therapies.

A modified TNM staging system for non-metastatic colorectal cancer based on nomogram analysis of SEER database

BackgroundTo revise the American Joint Committee on Cancer TNM staging system for colorectal cancer (CRC) based on a nomogram analysis of Surveillance, Epidemiology, and End Results (SEER) database, and to prove the rationality of enhancing T stage’s weighting in our previously proposed T-plus staging system.MethodsTotal 115,377 non-metastatic CRC patients from SEER were randomly grouped as training and testing set by ratio 1:1. The Nomo-staging system was established via three nomograms based on 1-year, 2-year and 3-year disease specific survival (DSS) Logistic regression analysis of the training set. The predictive value of Nomo-staging system for the testing set was evaluated by concordance index (c-index), likelihood ratio (L.R.) and Akaike information criteria (AIC) for 1-year, 2-year, 3-year overall survival (OS) and DSS. Kaplan–Meier survival curve was used to valuate discrimination and gradient monotonicity. And an external validation was performed on database from the Second Affiliated Hospital of Zhejiang University (SAHZU).ResultsPatients with T1-2xa0N1 and T1N2a were classified into stage II while T4xa0N0 patients were classified into stage III in Nomo-staging system. Kaplan–Meier survival curves of OS and DSS in testing set showed Nomo-staging system performed better in discrimination and gradient monotonicity, and the external validation in SAHZU database also showed distinctly better discrimination. The Nomo-staging system showed higher value in L.R. and c-index, and lower value in AIC when predicting OS and DSS in testing set.ConclusionThe Nomo-staging system showed better performance in prognosis prediction and the weight of lymph nodes status in prognosis prediction should be cautiously reconsidered.