Molecular Markers for Colorectal Cancer

RAF1 contributes to cell proliferation and STAT3 activation in colorectal cancer independently of microsatellite and KRAS status

More than 30% of all human cancers are driven by RAS mutations and activating KRAS mutations are present in 40% of colorectal cancer (CRC) in the two main CRC subgroups, MSS (Microsatellite Stable) and MSI (Microsatellite Instable). Studies in RAS-driven tumors have shown essential roles of the RAS effectors RAF and specifically of RAF1, which can be dependent or independent of RAF's ability to activate the MEK/ERK module. In this study, we demonstrate that RAF1, but not its kinase activity, plays a crucial role in the proliferation of both MSI and MSS CRC cell line-derived spheroids and patient-derived organoids, and independently of KRAS mutation status. Moreover, we could define a RAF1 transcriptomic signature which includes genes that contribute to STAT3 activation, and could demonstrate that RAF1 ablation decreases STAT3 phosphorylation in all CRC spheroids tested. The genes involved in STAT3 activation as well as STAT3 targets promoting angiogenesis were also downregulated in human primary tumors expressing low levels of RAF1. These results indicate that RAF1 could be an attractive therapeutic target in both MSI and MSS CRC regardless of their KRAS status and support the development of selective RAF1 degraders rather than RAF1 inhibitors for clinical use in combination therapies.

Is the combination of immunotherapy with conventional chemotherapy the key to increase the efficacy of colorectal cancer treatment?

Colorectal cancer (CRC) is among the most prevalent and deadly neoplasms worldwide. According to GLOBOCAN predictions, its incidence will increase from 1.15 million CRC cases in 2020 to 1.92 million cases in 2040. Therefore, a better understanding of the mechanisms involved in CRC development is necessary to improve strategies focused on reducing the incidence, prevalence, and mortality of this oncological pathology. Surgery, chemotherapy, and radiotherapy are the main strategies for treating CRC. The conventional chemotherapeutic agent utilized throughout the last four decades is 5-fluorouracil, notwithstanding its low efficiency as a single therapy. In contrast, combining 5-fluorouracil therapy with leucovorin and oxaliplatin or irinotecan increases its efficiency. However, these treatments have limited and temporary solutions and aggressive side effects. Additionally, most patients treated with these regimens develop drug resistance, which leads to disease progression. The immune response is considered a hallmark of cancer; thus, the use of new strategies and methodologies involving immune molecules, cells, and transcription factors has been suggested for CRC patients diagnosed in stages III and IV. Despite the critical advances in immunotherapy, the development and impact of immune checkpoint inhibitors on CRC is still under investigation because less than 25% of CRC patients display an increased 5-year survival. The causes of CRC are diverse and include modifiable environmental factors (smoking, diet, obesity, and alcoholism), individual genetic mutations, and inflammation-associated bowel diseases. Due to these diverse causes, the solutions likely cannot be generalized. Interestingly, new strategies, such as single-cell multiomics, proteomics, genomics, flow cytometry, and massive sequencing for tumor microenvironment analysis, are beginning to clarify the way forward. Thus, the individual mechanisms involved in developing the CRC microenvironment, their causes, and their consequences need to be understood from a genetic and immunological perspective. This review highlighted the importance of altering the immune response in CRC. It focused on drugs that may modulate the immune response and show specific efficacy and contrasted with evidence that immunosuppression or the promotion of the immune response is the answer to generating effective treatments with combined chemotherapeutic drugs.

Emerging agents that target signaling pathways to eradicate colorectal cancer stem cells

Colorectal cancer (CRC) represents the third most commonly diagnosed cancer and the second leading cause of cancer death worldwide. The modern concept of cancer biology indicates that cancer is formed of a small population of cells called cancer stem cells (CSCs), which present both pluripotency and self-renewal properties. These cells are considered responsible for the progression of the disease, recurrence and tumor resistance. Interestingly, some cell signaling pathways participate in CRC survival, proliferation, and self-renewal properties, and most of them are dysregulated in CSCs, including the Wingless (Wnt)/β-catenin, Notch, Hedgehog, nuclear factor kappa B (NF-κB), Janus kinase/signal transducer and activator of transcription (JAK/STAT), peroxisome proliferator-activated receptor (PPAR), phosphatidyl-inositol-3-kinase/Akt/mechanistic target of rapamycin (PI3K/Akt/mTOR), and transforming growth factor-β (TGF-β)/Smad pathways. In this review, we summarize the strategies for eradicating CRC stem cells by modulating these dysregulated pathways, which will contribute to the study of potential therapeutic schemes, combining conventional drugs with CSC-targeting drugs, and allowing better cure rates in anti-CRC therapy.

Synthesis, Biological, and Molecular Docking Studies on 4,5,6,7-Tetrahydrobenzo[b]thiophene Derivatives and Their Nanoparticles Targeting Colorectal Cancer

Initiation of colorectal carcinogenesis may be induced by chromosomal instability caused by oxidative stress or indirectly by bacterial infections. Moreover, proliferating tumor cells are characterized by reprogrammed glucose metabolism, which is associated with upregulation of PDK1 and LDHA enzymes. In the present study, some 4,5,6,7-tetrahydrobenzo[b]thiophene derivatives in addition to Fe₃O₄ and Fe₃O₄/SiO₂ nanoparticles (NPs) supported with a new Schiff base were synthesized for biological evaluation as PDK1 and LDHA inhibitors as well as antibacterial, antioxidant, and cytotoxic agents on LoVo and HCT-116 cells of colorectal cancer (CRC). The results showed that compound 1b is the most active as PDK1 and LDHA inhibitor with IC₅₀ values (μg/mL) of 57.10 and 64.10 compared to 25.75 and 15.60, which were produced by the standard inhibitors sodium dichloroacetate and sodium oxamate, respectively. NPs12a,b and compound 1b exhibited the strongest antioxidant properties with IC₅₀ values (μg/mL) of 80.0, 95.0, and 110.0 μg/mL, respectively, compared to 54.0 μg/mL, which was produced by butylated hydroxy toluene. Moreover, NPs12a and carbamate derivative 3b exhibited significant cytotoxic activities with IC₅₀ values (μg/mL) of 57.15 and 81.50 (LoVo cells) and 60.35 and 71.00 (HCT-116 cells). Thus, NPs12a and compound 3b would be considered as promising candidates suitable for further optimization to develop new chemopreventive and chemotherapeutic agents against these types of CRC cell lines. Besides, molecular docking in the colchicine binding site of the tubulin (TUB) domain revealed a good binding affinity of 3b to the protein; in addition, the absorption, distribution, metabolism, and excretion (ADME) analyses showed its desirable drug-likeness and oral bioavailability characteristics.

Knockdown of Forkhead box A1 suppresses the tumorigenesis and progression of human colon cancer cells through regulating the phosphatase and tensin homolog/Akt pathway

Background

This study aimed to evaluate the role and the underlying mechanisms of Forkhead box A1 (encoded by FOXA1) in colon cancer.

Methods

We analyzed FOXA1 mRNA and protein expression in colon cancer tissues and cell lines. We also silenced FOXA1 expression in HCT116 and SW480 cells to evaluate the effects on cell proliferation, cell cycle, migration, and invasion by using MTT, colony formation, flow cytometry, and the Transwell assay, respectively.

Results

FOXA1 immunostaining was higher in colon cancer tissues than adjacent healthy tissues. FOXA1 mRNA and protein expression was significantly increased in human colon cancer cells compared with a normal colonic cell line. FOXA1 expression was also significantly higher in colorectal cancer tissues from TCGA data sets and was associated with worse prognosis in the R2 database. FOXA1 expression was negatively correlated with the extent of its methylation, and its knockdown reduced proliferation, migration, and invasion, and induced G2/M phase arrest in HCT116 and SW480 cells by suppressing the phosphatase and tensin homolog/Akt signaling pathway and inhibiting epithelial–mesenchymal transition.

Conclusion

FOXA1 may act as an oncogene in colon cancer tumorigenesis and development.

Electrochemical biosensors for measurement of colorectal cancer biomarkers

Colorectal cancer (CRC) is associated with one of the highest rates of mortality among cancers worldwide. The early detection and management of CRC is imperative. Biomarkers play an important role in CRC screening tests, CRC treatment, and prognosis and clinical management; thus rapid and sensitive detection of biomarkers is helpful for early detection of CRC. In recent years, electrochemical biosensors for detecting CRC biomarkers have been widely investigated. In this review, different electrochemical detection methods for CRC biomarkers including immunosensors, aptasensors, and genosensors are summarized. Further, representative examples are provided that demonstrate the advantages of electrochemical sensors modified by various nanomaterials. Finally, the limitations and prospects of biomarkers and electrochemical sensors in detection are also discussed. Graphical abstract.

Multi-center real-world comparison of the fully automated Idylla™ microsatellite instability assay with routine molecular methods and immunohistochemistry on formalin-fixed paraffin-embedded tissue of colorectal cancer

Microsatellite instability (MSI) is present in 15–20% of primary colorectal cancers. MSI status is assessed to detect Lynch syndrome, guide adjuvant chemotherapy, determine prognosis, and use as a companion test for checkpoint blockade inhibitors. Traditionally, MSI status is determined by immunohistochemistry or molecular methods. The Idylla™ MSI Assay is a fully automated molecular method (including automated result interpretation), using seven novel MSI biomarkers (ACVR2A, BTBD7, DIDO1, MRE11, RYR3, SEC31A, SULF2) and not requiring matched normal tissue. In this real-world global study, 44 clinical centers performed Idylla™ testing on a total of 1301 archived colorectal cancer formalin-fixed, paraffin-embedded (FFPE) tissue sections and compared Idylla™ results against available results from routine diagnostic testing in those sites. MSI mutations detected with the Idylla™ MSI Assay were equally distributed over the seven biomarkers, and 84.48% of the MSI-high samples had ≥ 5 mutated biomarkers, while 98.25% of the microsatellite-stable samples had zero mutated biomarkers. The concordance level between the Idylla™ MSI Assay and immunohistochemistry was 96.39% (988/1025); 17/37 discordant samples were found to be concordant when a third method was used. Compared with routine molecular methods, the concordance level was 98.01% (789/805); third-method analysis found concordance for 8/16 discordant samples. The failure rate of the Idylla™ MSI Assay (0.23%; 3/1301) was lower than that of referenced immunohistochemistry (4.37%; 47/1075) or molecular assays (0.86%; 7/812). In conclusion, lower failure rates and high concordance levels were found between the Idylla™ MSI Assay and routine tests.

Biomarkers and intermediate-high risk non-muscle invasive bladder cancer: a multivariate analysis of three different cellular pathways with pronostic implications

PURPOSE

To determine the presence of a group of mutations, and establish the prognostic value for recurrence and progression.

MATERIALS AND METHODS

Prospective observational study. Intermediate-to-high-risk non-muscle invasive bladder cancer (NMIBC) was evaluated. Data from genetic analyses were included in a database along with clinicopathological variables of interest.

RESULTS

Seventy-four patients. Twenty-five (33.8%) recurred and 3 (4.1%) progressed. Median time to recurrence: 8 months (5.7-12.7). Median time to progression: 14 months (P75: 12). Mutation distribution: KRAS codon 12: one patient (1.4%), BAT25: five patients (6.8%), BAT-26: four patients (5.4%), and D2S123: 6 patients (8.1%). Arg72Pro polymorphism: 50 patients (67.6%) exhibited homozygous mutations, 23 (31.1%) were heterozygous, and 1 patient (1.4%) did not present the mutation. We found an association between presence of MSI at BAT26 and female sex (p < 0.05) and tumor stage and the TP53 Arg72Pro polymorphism. Recurrence-free survival (RFS) was significantly associated with presence of MSI at D2S123, with a HR of 5.44 for patients presenting the mutation (95% CI 1.83-16.16). On multivariate analysis, we found a statistically significant increase in risk of recurrence among patients with MSI at D2S123 (HR 5.15; p < 0.05) and more than 2 previous transurethral bladder resections (TURBs) (HR 5.07; p < 0.05) adjusted for tumor stage and grade. Harrell's concordance index revealed an accuracy of 0.74 (p < 0.05).

CONCLUSION

An association was found between presence BAT26 MSI and female sex, Arg72Pro polymorphism with tumor stage and D2S123 and more than 2 TUR procedures were associated with RFS adjusted to tumor stage and grade.

Downregulation of ORP3 Correlates with Reduced Survival of Colon Cancer Patients with Advanced Nodal Metastasis and of Female Patients with Grade 3 Colon Cancer

Genome instability is an essential hallmark in tumor development, including colorectal cancer. We have recently identified the oxysterol binding protein-related protein 3 (ORP3), also known as oxysterol binding protein-like 3 (OSBPL3), as a novel ploidy-control gene, whose knock-out leads to aneuploidy induction and promotes tumor formation, indicating that ORP3 is a bona fide tumor suppressor protein. Here we analyzed expression of ORP3 in a cohort (n = 206) of colon cancer patients in relation to patient survival. We show that low ORP3 mRNA levels correlate with reduced survival of patients with advanced nodal metastasis (N2). While patient survival does not associate with grading when the whole cohort is evaluated, importantly, low ORP3 mRNA levels associate with worse survival of female patients with grade 3 colon cancer. Similarly, low ORP3 mRNA levels associate with worse survival of grade 3 colon cancer patients 70 years of age and younger while low ORP3 mRNA levels seem to be beneficial for colon cancer patients with a T2 tumor size. Together, the data show that ORP3 expression is downregulated during colon cancer progression, which correlates with reduced patient survival. Thus, ORP3 mRNA levels may be a prognostic marker for better stratification of colon cancer patients.

Colorectal Cancer Early Detection in Stool Samples Tracing CpG Islands Methylation Alterations Affecting Gene Expression

Colorectal cancer (CRC) is a major cause of cancer mortality. Early diagnosis is relevant for its prevention and treatment. Since DNA methylation alterations are early events in tumourigenesis and can be detected in cell-free DNA, they represent promising biomarkers for early CRC diagnosis through non-invasive methods. In our previous work, we identified 74 early altered CpG islands (CGIs) associated with genes involved in cell cross-talking and cell signalling pathways. The aim of this work was to test whether methylation-based biomarkers could be detected in non-invasive matrices. Our results confirmed methylation alterations of GRIA4 and VIPR2 in CRC tissues, using MethyLight, as well as in stool samples, using a much more sensitive technique as droplet digital PCR. Furthermore, we analysed expression levels of selected genes whose promoter CGIs were hypermethylated in CRC, detecting downregulation at mRNA and protein levels in CRC tissue for GRIA4, VIPR2, SPOCK1 and SLC6A3. Most of these genes were already lowly expressed in colon normal tissues supporting the idea that cancer DNA methylation targets genes already barely expressed in the matched normal tissues. Our study suggests GRIA4 and VIPR2 as biomarkers for early CRC diagnosis using stool samples and confirms downregulation of genes hypermethylated in CRC.

Increased Temperature Facilitates Adeno-Associated Virus Vector Transduction of Colorectal Cancer Cell Lines in a Manner Dependent on Heat Shock Protein Signature

Colorectal cancer (CRC) is one of the most common cancers in human population. A great achievement in the treatment of CRC was the introduction of targeted biological drugs and solutions of chemotherapy, combined with hyperthermia. Cytoreductive surgery and HIPEC (hyperthermic intraperitoneal chemotherapy) extends the patients' survival with CRC. Recently, gene therapy approaches are also postulated. The studies indicate the possibility of enhancing the gene transfer to cells by recombinant adeno-associated vectors (rAAV) at hyperthermia. The rAAV vectors arouse a lot of attention in the field of cancer treatment due to many advantages. In this study, the effect of elevated temperature on the transduction efficiency of rAAV vectors on CRC cells with different origin and gene profile was examined. The effect of heat shock on the penetration of rAAV vectors into CRC cells in relation with the expression of HSP and AAV receptor genes was tested. It was found that the examined cells under hyperthermia (43°C, 1 h) are transduced at a higher level than in normal conditions (37°C). The results also indicate that studied RKO, HT-29, and LS411N cell lines express HSP genes at different levels under both 37°C and 43°C. Moreover, the results showed that the expression of AAV receptors increases in response to elevated temperature. The study suggests that increased rAAV transfer to CRC can be achieved under elevated temperature conditions. The obtained results provide information relevant to the design of new solutions in CRC therapy based on the combination of hyperthermia, chemotherapy, and gene therapy.

Neoadjuvant chemoradiotherapy might provide survival benefit in patients with stage IIIb/IIIc locally advanced rectal cancer: A retrospective single-institution study with propensity score-matched comparative analysis

BACKGROUND

Neoadjuvant chemoradiotherapy (NACRT) and total mesorectal excision (TME) are standard treatments of stage II/III locally advanced rectal cancer (LARC), currently. Here, we evaluated the oncological outcomes in LARC patients treated with NACRT compared to TME alone, and determined whether tumor regression grade (TRG) and pathologic response after NACRT was related to prognosis.

METHODS

This is a retrospective comparison of 358 LARC patients treated with either TME alone (non-NACRT group, n = 173) or NACRT plus TME (NACRT group, n = 185) during 2003-2013. Perioperative and oncologic outcomes, like overall survival (OS), disease-free survival (DFS) and recurrence were compared using 1:1 propensity score matching analysis.

RESULTS

A total of 133 patients were matched for the analysis. After a median follow-up of 45 months (8-97 months), the 5-year OS (NACRT vs non-NACRT: 75.42% vs 72.76%; P = 0.594) and 5-year DFS (NACRT vs non-NACRT: 74.25% vs 70.13%; P = 0.224) were comparable between NACRT and non-NACRT, whereas the 5-year DFS rate was higher in the NACRT group when only stage IIIb/IIIc patients were considered (NACRT vs. non-NACRT: 74.79% vs. 62.29%; P = 0.056). In the NACRT group of 185 patients, those with pCR/stage I (vs stage II/stage III disease) or TRG3/TRG4 disease (vs TRG0/TRG1/TRG2) had significantly better prognosis.

CONCLUSION

NACRT might provide survival benefit in patients with stage IIIb/IIIc locally advanced rectal cancer.

Tumor-induced DNA methylation in the white blood cells of patients with colorectal cancer

The secretions of cancer cells alter epigenetic regulation in cancer stromal cells. The present study investigated the methylation changes in white blood cells (WBCs) caused by the secretions of colorectal cancer (CRC) cells. Changes in the DNA methylation of peripheral blood mononuclear cells (PBMCs) from normal individuals co-cultured with CRC cells were estimated using a methylation microarray. These changes were then compared against the DNA methylation changes and mRNA levels observed in the WBCs of patients with CRC. Procollagen-lysine, 2-oxoglutarate 5-dioxygenase 1 (PLOD1) and matrix metalloproteinase 9 (MMP9) were selected to assess the DNA methylation of the WBCs from CRC patients using real-time methylation-specific PCR. The majority of the genes analyzed presented high levels of mRNA in the WBCs of the patients with CRC and DNA methylation in the co-cultured PBMCs. Intragenic methylation revealed the strongest association (P=8.52×10^-21). For validation, MMP9 and PLOD1 were selected and used to test WBCs from 32 patients with CRC and 57 normal controls. The intragenic MMP9 methylation was commonly found (P<0.0001) with high sensitivity (90.63%) and high specificity (96.49%), and a positive predictive value of 93.33% and a negative predictive value of 93.22%. PLOD1 methylation was revealed to have lower sensitivity (30.00%) but higher specificity (97.92%). In addition to circulating WBCs, MMP9 protein expression was observed in infiltrating WBCs and the metastatic lymph nodes of patients with CRC. In conclusion, CRC cells secrete factors that induce genome wide DNA methylation changes in the WBCs of patients with CRC. These changes, including intragenic MMP9 methylation in WBCs, are promising CRC biomarkers to be tested in future CRC screening studies.

Primary Tumor Location in Colorectal Cancer: Comparison of Right- and Left-Sided Colorectal Cancer Characteristics for the Interventional Radiologist

One area which has emerged as an important factor for predicting molecular profile and treatment outcomes in metastatic colorectal cancer (mCRC) is primary tumor location. The importance of molecular characteristics of colorectal cancer has been firmly established in terms of prognosis and treatment algorithms for many years. Recent studies have also suggested that molecular profiles are important in locoregional therapies as well, with some data suggesting changes in treatment algorithms based on tumor location. Therefore, it is important for interventional radiologists to understand the basic molecular characteristics and development pathways of mCRC. Here, these disease characteristics are reviewed and the differences in left- versus right-sided primary tumor location are explored.

Adiponectin and colon cancer: evidence for inhibitory effects on viability and migration of human colorectal cell lines

Adiponectin (Acrp30) is an adipokine widely studied for its beneficial metabolic and anti-inflammatory properties. Colorectal cancer is among the most common cancers worldwide. The aim of present study was to explore the effects of Acrp30 on both CaCo-2 and HCT116 colorectal cancer cells in terms of viability, oxidative stress, and apoptosis. In addition, since colorectal cancer represents a typical inflammation-related cancer, we investigated whether Acrp30 treatment modifies the migration and the expression of crucial proteins in the EMT transition. Finally, we analyzed the expression of cytokines in CaCo-2 cells. We found that Acrp30 reduces the survival rate of both CaCo-2 and HCT116 cells through induction of apoptosis and oxidative stress already after 24 h of treatment. In addition, wound-healing assay indicated that Acrp30 exposure statistically inhibits CaCo-2 and HCT116 cell migration. Western blot analysis performed on E-cadherin and vimentin, two EMT crucial markers in carcinogenesis, indicated that Acrp30 does not influence EMT transition. Finally, we found a reduction of mRNA levels corresponding to the anti-inflammatory IL-10 cytokine together with an increase of the pro-inflammatory IL-6 and IL-8 cytokines. This study provides new insight into Acrp30 molecular effects on colorectal cancer cells. Indeed, even if further studies are necessary to clarify the precise role of Acrp30 in colorectal cancer, our data strongly suggest that Acrp30 negatively regulates cell survival and migration in association with induction of oxidative stress and regulation of cytokines expression in both CaCo-2 and HCT116 colorectal cells.