KRAS and TP53 mutations in colorectal carcinoma

Unraveling the role of disulfidptosis-related LncRNAs in colon cancer: a prognostic indicator for immunotherapy response, chemotherapy sensitivity, and insights into cell death mechanisms

Background: Colon cancer, a prevalent and deadly malignancy worldwide, ranks as the third leading cause of cancer-related mortality. Disulfidptosis stress triggers a unique form of programmed cell death known as disulfidoptosis, characterized by excessive intracellular cystine accumulation. This study aimed to establish reliable bioindicators based on long non-coding RNAs (LncRNAs) associated with disulfidptosis-induced cell death, providing novel insights into immunotherapeutic response and prognostic assessment in patients with colon adenocarcinoma (COAD). Methods: Univariate Cox proportional hazard analysis and Lasso regression analysis were performed to identify differentially expressed genes strongly associated with prognosis. Subsequently, a multifactorial model for prognostic risk assessment was developed using multiple Cox proportional hazard regression. Furthermore, we conducted comprehensive evaluations of the characteristics of disulfidptosis response-related LncRNAs, considering clinicopathological features, tumor microenvironment, and chemotherapy sensitivity. The expression levels of prognosis-related genes in COAD patients were validated using quantitative real-time fluorescence PCR (qRT-PCR). Additionally, the role of ZEB1-SA1 in colon cancer was investigated through CCK8 assays, wound healing experiment and transwell experiments. Results: disulfidptosis response-related LncRNAs were identified as robust predictors of COAD prognosis. Multifactorial analysis revealed that the risk score derived from these LncRNAs served as an independent prognostic factor for COAD. Patients in the low-risk group exhibited superior overall survival (OS) compared to those in the high-risk group. Accordingly, our developed Nomogram prediction model, integrating clinical characteristics and risk scores, demonstrated excellent prognostic efficacy. In vitro experiments demonstrated that ZEB1-SA1 promoted the proliferation and migration of COAD cells. Conclusion: Leveraging medical big data and artificial intelligence, we constructed a prediction model for disulfidptosis response-related LncRNAs based on the TCGA-COAD cohort, enabling accurate prognostic prediction in colon cancer patients. The implementation of this model in clinical practice can facilitate precise classification of COAD patients, identification of specific subgroups more likely to respond favorably to immunotherapy and chemotherapy, and inform the development of personalized treatment strategies for COAD patients based on scientific evidence.

RNA-Seq-Based Molecular Classification Analyses in Colorectal Cancer and Synchronous Adenoma

Colorectal cancers (CRC) are classified into consensus molecular subtypes (CMS) based on gene expression profiles. The revised classification system iCMS was proposed by considering intrinsic epithelial status, microsatellite instability (MSI), and fibrosis. This study aimed to provide molecular evidence for the adenoma-carcinoma sequence concept by examining CRC and synchronous adenomas using iCMS. Epithelial CMS cell proportion was estimated using CiberSortx, an in silico cell fractionation method that included CMS cell types among the reference cell types. A random forest (RF) model estimated the posterior probabilities of CMS classes, which were compared with the CiberSortx results. Gene expression profiles of the published iCMS signature panel were retrieved from our dataset and subjected to heatmap clustering for classification. Bulk RNA sequencing data were collected from 29 adenocarcinomas and 11 adenoma samples. CiberSortx showed all CRC contained either CMS2 or CMS3 as the major epithelial cancer cell type. The RF model classified approximately half of the CRC as CMS4, whereas CMS4 was hardly detected by CiberSortx. Because they were enriched with myofibroblasts as per the CiberSortx classification, we tentatively designated them as iCMS2-F/iCMS3-F. iCMS coupled with the application of an in silico cell fractionation method can provide the molecular dissection of CRC and adenoma.

Transcriptomic Analyses of the Adenoma-Carcinoma Sequence Identify Hallmarks Associated With the Onset of Colorectal Cancer

The concept of the adenoma-carcinoma sequence in colorectal cancer (CRC) is widely accepted. However, the relationship between the characteristics of the transcriptome and the adenoma-carcinoma sequence in CRC remains unclear. Here, the transcriptome profiles of 15 tissue samples from five CRC patients were generated by RNAseq. Six specific dynamic expression patterns of differentially expressed genes (DEGs) were generated by mFuzz. Weighted correlation network analysis showed that DEGs in cluster 4 were associated with carcinoma tissues, and those in cluster 6 were associated with non-normal tissues. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses identified metabolic dysregulation as a consistent finding throughout the transition process, whereas downregulation of the immune response occurred during normal to adenoma transition, and the upregulation of canonical pathways was associated with adenoma to carcinoma transition. Overall survival analysis of patients in cluster 6 identified TPD52L1 as a marker of poor prognosis, and cell proliferation, colony formation, wound healing, and Transwell invasion assays showed that high expression levels of TPD52L1 promoted malignant behaviors. In total, 70 proteins were identified as potential partners of hD53 by mass spectrometry. CRC formation was associated with three cancer hallmarks: dysregulation of metabolism, inactivation of the immune response, and activation of canonical cancer pathways. The TPD52L1 gene was identified as a potential marker to track tumor formation in CRC and as an indicator of poor patient prognosis.

Chemosensitization of HT29 and HT29-5FU Cell Lines by a Combination of a Multi-Tyrosine Kinase Inhibitor and 5FU Downregulates ABCC1 and Inhibits PIK3CA in Light of Their Importance in Saudi Colorectal Cancer

Colorectal cancer (CRC) remains one of the main causes of death worldwide and in Saudi Arabia. The toxicity and the development of resistance against 5 fluorouracil 5FU pose increasing therapeutic difficulties, which necessitates the development of personalized drugs and drug combinations. Objectives: First, to determine the most important kinases and kinase pathways, and the amount of ABC transporters and KRAS in samples taken from Saudi CRC patients. Second, to investigate the chemosensitizing effect of LY294002 and HAA₂₀₂₀ and their combinations with 5FU on HT29, HT29-5FU, HCT116, and HCT116-5FU CRC cells, their effect on the three ABC transporters, cell cycle, and apoptosis, in light of the important kinase pathways resulting from the first part of this study. Methods: The PamChip^® peptide micro-array profiling was used to determine the level of kinase and targets in the Saudi CRC samples. Next, RT-PCR, MTT cytotoxicity, Western blotting, perturbation of cell cycle, annexin V, and immunofluorescence assays were used to investigate the effect on CRC, MRC5, and HUVEC cells. Results: The kinase activity profiling highlighted the importance of the PI3K/AKT, MAPK, and the growth factors pathways in the Saudi CRC samples. PIK3CA was the most overexpressed, and it was associated with increased level of mutated KRAS and the three ABC transporters, especially ABCC1 in the Saudi samples. Next, combining HAA₂₀₂₀ with 5FU exhibited the best synergistic and resistance-reversal effect in the four CRC cells, and the highest selectivity indices compared to MRC5 and HUVEC normal cells. Additionally, HAA₂₀₂₀ with 5FU exerted significant inhibition of ABCC1 in the four CRC cells, and inhibition of PIK3CA/AKT/MAPK7/ERK in HT29 and HT29-5FU cells. The combination also inhibited EGFR, increased the preG₁/S cell cycle phases, apoptosis, and caspase 8 in HT29 cells, while it increased the G₁ phase, p21/p27, and apoptosis in HT29-5FU cells. Conclusion: We have combined the PamChip kinase profiling of Saudi CRC samples with in vitro drug combination studies in four CRC cells, highlighting the importance of targeting PIK3CA and ABCC1 for Saudi CRC patients, especially given that the overexpression of PIK3CA mutations was previously linked with the lack of activity for the anti-EGFRs as first line treatment for CRC patients. The combination of HAA₂₀₂₀ and 5FU has selectively sensitized the four CRC cells to 5FU and could be further studied.

Colorectal cancer in Saudi Arabia as the proof-of-principle model for implementing strategies of predictive, preventive, and personalized medicine in healthcare

Colorectal cancer (CRC) is the most commonly diagnosed cancer among Saudi males and ranks third in females with up to 73% of cases diagnosed at late stage. This review provides an analysis of CRC situation in the Kingdom of Saudi Arabia (KSA) from healthcare perspective. A PUBMED (1986-2018) search was done to identify publications focusing on CRC in KSA. Due to reports of increased CRC incidence among young age group (< 50), and given the young population of KSA, the disease may burden the national healthcare system in the next decades. Environmental factors attributed to increasing incidence rates of CRC include red meat consumption, sedentary lifestyle, and increased calorie intake. Despite substantial investment in healthcare, attention to predictive diagnostics and targeted prevention is lacking. There is a need to develop national screening guidelines based on evidence that supports a reduction in incidence and mortality of CRC when screening is implemented. Future approaches are discussed based on multi-level diagnostics, risk assessment, and population screening programs focused on the needs of young populations that among others present the contents of the advanced approach by predictive, preventive, and personalized medicine. Recommendations are provided that could help to develop policies at regional and national levels. Countries with demographics and lifestyle similar to KSA may gain insights from this review to shape their policies and procedures.

The Correlation of KRAS Gene Expression and P53 Immunoexpression in Colorectal Adenocarcinoma

BACKGROUND:

Colorectal Adenocarcinoma (ADCCR) is the third most cancer not only in the world but also in Indonesia. There were 623 cases of ADCCR at Dr Hasan Sadikin hospital within 2015-2017. Both KRAS and TP53 mutation are known as genes which involve in carcinogenesis through the same pathway, namely the chromosomal instability pathway. In West Java, researches focusing on mutation KRAS and p53 also a correlation between both biomarkers among ADCCR patients are still limited.

AIM:

Therefore, this research aimed to perceive a correlation between KRAS gene expression with p53 immunoexpression in ADCCR.

METHODS:

Cross section research design was performed to 62 cases of ADCCR as paraffin block taken from 4 hospitals in West Java, including Dr Hasan Sadikin hospital Bandung, Santosa hospital Bandung, Borromeus hospital Bandung and Syamsudin hospital Sukabumi from January 1st 2014 to 31s November 2018. KRAS mutation gene data taken from secondary data at molecular laboratory in Ciptomangunkusumo Hospital Jakarta and Dr Sardjito Hospital Jogjakarta, while the detection of p53 immunoexpression data using immunohistochemical staining was carried out in the Laboratorium of Anatomical Pathology of Padjadjaran University (Dr Hasan Sadikin Hospital). All data were analysed using Chi-Square test with p-value < 0,05 of significant level then proceeded with Stata ver.11 for windows.

RESULTS:

The results of this study showed that KRAS gene expressions from 62 sample consist of 39 wild type KRAS (62.39%) and 23 mutant KRAS (37.1%). The p53 immunoexpression consists of 27 negative cases (non-mutant p53) and 35 mutant p53, which includes 10 cases as focal expression (16.33%) and 25 cases as diffuse expressions (40.33%). There is a significant association between KRAS gene expression and p53 immunoexpressions in ADCCR (p = 0.04), with mild positive correlation (Rho 0.28).

CONCLUSION:

This study concluded that KRAS and p53 mutations are involved in carcinogenesis, and the p53 mutation is a more dominant risk factor than KRAS mutation among West Java people. P53 mutations with diffuse pattern tend to express mutant KRAS while p53 negative and having a focal pattern tend to express wt KRAS.

SOX9 Stem-Cell Factor: Clinical and Functional Relevance in Cancer

Transcriptional and epigenetic embryonic programs can be reactivated in cancer cells. As result, a specific subset of undifferentiated cells with stem-cells properties emerges and drives tumorigenesis. Recent findings have shown that ectoderm- and endoderm-derived tissues continue expressing stem-cells related transcription factors of the SOX-family of proteins such as SOX2 and SOX9 which have been implicated in the presence of cancer stem-like cells (CSCs) in tumors. Currently, there is enough evidence suggesting an oncogenic role for SOX9 in different types of human cancers. This review provides a summary of the current knowledge about the involvement of SOX9 in development and progression of cancer. Understanding the functional roles of SOX9 and clinical relevance is crucial for developing novel treatments targeting CSCs in cancer.

Inducible Intestine-Specific Expression of krasV12 Triggers Intestinal Tumorigenesis In Transgenic Zebrafish

KRAS mutations are a major risk factor in colorectal cancers. In particular, a point mutation of KRAS of amino acid 12, such as KRAS^V12, renders it stable activity in oncogenesis. We found that kras^V12 promotes intestinal carcinogenesis by generating a transgenic zebrafish line with inducible kras^V12 expression in the intestine, Tg(ifabp:EGFP-kras^V12). The transgenic fish generated exhibited significant increases in the rates of intestinal epithelial outgrowth, proliferation, and cross talk in the active Ras signaling pathway involving in epithelial-mesenchymal transition (EMT). These results provide in vivo evidence of Ras pathway activation via kras^V12 overexpression. Long-term transgenic expression of kras^V12 resulted in enteritis, epithelial hyperplasia, and tubular adenoma in adult fish. This was accompanied by increased levels of the signaling proteins p-Erk and p-Akt and by downregulation of the EMT marker E-cadherin. Furthermore, we also observed a synergistic effect of kras^V12 expression and dextran sodium sulfate treatment to enhance intestinal tumor in zebrafish. Our results demonstrate that kras^V12 overexpression induces intestinal tumorigenesis in zebrafish, which mimics intestinal tumor formation in humans. Thus, our transgenic zebrafish may provide a valuable in vivo platform that can be used to investigate tumor initiation and anticancer drugs for gastrointestinal cancers.

MicroRNA-552 links Wnt signaling to p53 tumor suppressor in colorectal cancer

The aberrant expression of microRNAs (miRNAs or miRs) has been shown to be associated with the development of various types of cancer, including colorectal cancer (CRC). The increased activation of the Wnt signaling pathway via the loss of the Wnt repressor, adenomatous polyposis coli (APC), is the hallmark of human CRC. In this study, we demonstrate that the activation of the Wnt/c-Myc axis inhibits the expression of the tumor suppressor, p53, via promoting the targeting of p53 by miR‑552. Our results revealed that the ectopic expression of miR‑552 enhanced cell proliferation, colony formation and resistance to drug-induced apoptosis, suggesting that this miRNA may function as an oncogene. We found that miR‑552 displayed oncogenic properties by directly targeting the p53 tumor suppressor. Of note, our genetic and pharmacological experiments revealed that the Wnt/β-catenin signaling pathway and its major downstream target, c-Myc (hereafter termed Myc), increased the miR‑552 levels, and chromatin immunoprecipitation (ChIP) assays revealed they carried out this function by directly binding to their binding sites in the miR‑552 promoter region. Given that the functional loss of APC, leading to abnormal Wnt signals, and the absence of p53 protein are common in CRC, these results suggest that miR‑552 may serve as an important link between these two events, and this warrants further investigation. Collectively, the data of this study suggest that the inhibition of miR‑552 may disconnect elevated Wnt signals from p53 suppression, providing a novel therapeutic strategy for patients with CRC with deregulated Wnt signaling.

Correlation between RAS Test Results and Prognosis of Metastatic Colorectal Cancer Patients: a Report from Western Iran

In the patients with metastatic colorectal cancer (mCRC), RAS testing is the first step to identify those that could benefit from anti-EGFR therapy. This study examined associations between KRAS mutations and clinicopathological and survival data in Iranian patients with mCRC. Between 2008 to2015 in a retrospective study, 83 cases of mCRC were referred to the Clinic of Medical Oncology. The mean follow-up was 45 months that there were 27 deaths. The 3 patients that did not complete follow-up were censored from the study. KRAS and NRAS were analyzed using allele-specific PCR primers and pyrosequencing in exons 2, 3 and 4. Multivariate survival analysis using Cox's regression model was used for affecting of variables on overall survival (OS). The mean age at diagnosis for patients was 57.7 (range, 18 to 80 years) and 61.4% were male. There was no significant different between prognostic factors and KRAS mutation with wild-type. Also, There was no significant different between KRAS mutation and KRAS wild-type for survival, but there was a significant different between KRAS 12 and 13 mutations for survival (HR 0.13, 95% CI 0.03-0.66, P=0.01). In conclusion, the prevalence of KRAS mutations in CRC patients was below 50% but higher than in other studies in Iran. As in many studies, patients with KRAS 12 mutations had better OS thn those with KRAS 13 mutation. In addition to KRAS testing, other biomarkers are needed to determine the best treatment for patients with mCRC.

Mutations of p53 and K-ras correlate TF expression in human colorectal carcinomas: TF downregulation as a marker of poor prognosis

BACKGROUND

Tissue factor (TF) is emphasized as the promising target in the future targeted therapy strategy for colorectal cancer (CRC). Recent evidence showed that TF expression is under the control of K-ras and p53. However, a comprehensive evaluation of TF expression, K-ras status, and p53 mutation has not been systematically analyzed. The aims of this study were to identify the percentages of positive TF in CRC patients; analyze the associations of TF expression, K-ras status, and p53 mutation; and evaluate the prognostic value of TF in CRC patients.

METHODS

Ninety-six CRC samples were tested for TF expression, p53 mutation, and K-ras status by semiquantitative immunohistochemistry, Western blotting analysis, direct sequencing, and real-time quantitative PCR. Associations were sought with TF expression and clinical outcomes.

RESULTS

TF expression was related to clinical stages, tumor differentiation, and tumor size. The positive proportions of TF expression on tumor cells and tumor vascular endothelial cells were 70% and 53% respectively in CRC patients. The positive proportion of TF co-expression on both cancer cells and tumor vascular endothelial cells was 40%, compared to an 83% total TF positive proportion in CRC patients. TF expression on CRC appeared to be increased with K-ras and/or p53 mutation(s). Disease-free survival and overall survival were significantly reduced in CRC patients with high TF expression.

CONCLUSIONS

TF may participate in both K-ras and p53 mutations involved in colorectal carcinogenesis and could be considered as a prognostic indicator for patients CRC.