Personalized Medicine-Current and Emerging Predictive and Prognostic Biomarkers in Colorectal Cancer

Evaluation of the Immunohistochemical Scoring System of CDX2 Expression as a Prognostic Biomarker in Colon Cancer

Encoded by the CDX2 homeobox gene, the CDX2 protein assumes the role of a pivotal transcription factor localized within the nucleus of intestinal epithelial cells, orchestrating the delicate equilibrium of intestinal physiology while intricately guiding the precise development and differentiation of epithelial tissue. Emerging research has unveiled that positive immunohistochemical expression of this protein shows that the CDX2 gene exerts a potent suppressive impact on tumor advancement in colorectal cancer, impeding the proliferation and distant dissemination of tumor cells, while the inhibition or suppression of CDX2 frequently correlates with aggressive behavior in colorectal cancer. In this study, we conducted an immunohistochemical assessment of CDX2 expression on a cohort of 43 intraoperatively obtained tumor specimens from patients diagnosed with colon cancer at Colțea Clinical Hospital in Bucharest, between April 2019 and December 2023. Additionally, we shed light on the morphological diversity within colon tumors, uncovering varying differentiation grades within the same tumor, reflecting the variations in CDX2 expression as well as the genetic complexity underlying these tumors. Based on the findings, we developed an innovative immunohistochemical scoring system that addresses the heterogeneous nature of colon tumors. Comprehensive statistical analysis of CDX2 immunohistochemical expression unveiled significant correlations with known histopathological parameters such as tumor differentiation grades (p-value = 0.011) and tumor budding score (p-value = 0.002), providing intriguing insights into the complex involvement of the CDX2 gene in orchestrating tumor progression through modulation of differentiation processes, and highlighting its role in metastatic predisposition. The compelling correlation identified between CDX2 expression and conventional histopathological parameters emphasizes the prognostic significance of the CDX2 biomarker in colon cancer. Moreover, our novel immunohistochemical scoring system reveals a distinct subset of colon tumors exhibiting reserved prognostic outcomes, distinguished by their "mosaic" CDX2 expression pattern.

Innovative PNA-LB mediated allele-specific LAMP for KRAS mutation profiling on a compact lab-on-a-disc device

Tailored healthcare, an approach focused on individual patients, requires integrating emerging interdisciplinary technologies to develop accurate and user-friendly diagnostic tools. KRAS mutations, prevalent in various common cancers, are crucial determinants in selecting patients for novel KRAS inhibitor therapies. This study presents a novel state-of-the-art Lab-on-a-Disc system utilizing peptide nucleic acids-loop backward (PNA-LB) mediated allele-specific loop-mediated isothermal amplification (LAMP) for detecting the frequent G12D KRAS mutation, signifying its superiority over alternative mutation detection approaches. The designed Lab-on-a-Disc system demonstrated exceptional preclinical and technical precision, accuracy, and versatility. By applying varying cutoff values to PNA- LB LAMP reactions, the assay's sensitivity and specificity were increased by 80 % and 90 %, respectively. The device's key advantages include a robust microfluidic Lab-on-a-Disc design, precise rotary control, and a cutting-edge induction heating module. These features enable multiplexing of LAMP reactions with high reproducibility and repeatability, with CV% values less than 3.5 % and 5.5 %, respectively. The device offers several methods for accurate endpoint result detection, including naked-eye observation, RGB image analysis using Python code, and time of fluorescence (Tf) values. Preclinical specificity and sensitivity, assessed using different cutoffs for Eva-Green fluorescence Tf values and pH-sensitive dyes, demonstrated comparable performance to the best standard methods. Overall, this study represents a significant step towards tailoring treatment strategies for cancer patients through precise and efficient mutation detection technologies.

Prognostic Biomarkers of Cell Proliferation in Colorectal Cancer (CRC): From Immunohistochemistry to Molecular Biology Techniques

Colorectal cancer (CRC) is one of the most common and severe malignancies worldwide. Recent advances in diagnostic methods allow for more accurate identification and detection of several molecular biomarkers associated with this cancer. Nonetheless, non-invasive and effective prognostic and predictive testing in CRC patients remains challenging. Classical prognostic genetic markers comprise mutations in several genes (e.g., APC, KRAS/BRAF, TGF-β, and TP53). Furthermore, CIN and MSI serve as chromosomal markers, while epigenetic markers include CIMP and many other candidates such as SERP, p14, p16, LINE-1, and RASSF1A. The number of proliferation-related long non-coding RNAs (e.g., SNHG1, SNHG6, MALAT-1, CRNDE) and microRNAs (e.g., miR-20a, miR-21, miR-143, miR-145, miR-181a/b) that could serve as potential CRC markers has also steadily increased in recent years. Among the immunohistochemical (IHC) proliferative markers, the prognostic value regarding the patients' overall survival (OS) or disease-free survival (DFS) has been confirmed for thymidylate synthase (TS), cyclin B1, cyclin D1, proliferating cell nuclear antigen (PCNA), and Ki-67. In most cases, the overexpression of these markers in tissues was related to worse OS and DFS. However, slowly proliferating cells should also be considered in CRC therapy (especially radiotherapy) as they could represent a reservoir from which cells are recruited to replenish the rapidly proliferating population in response to cell-damaging factors. Considering the above, the aim of this article is to review the most common proliferative markers assessed using various methods including IHC and selected molecular biology techniques (e.g., qRT-PCR, in situ hybridization, RNA/DNA sequencing, next-generation sequencing) as prognostic and predictive markers in CRC.

Combinatorial treatment with statins and niclosamide prevents CRC dissemination by unhinging the MACC1-β-catenin-S100A4 axis of metastasis

Colorectal cancer (CRC) is the second-most common malignant disease worldwide, and metastasis is the main culprit of CRC-related death. Metachronous metastases remain to be an unpredictable, unpreventable, and fatal complication, and tracing the molecular chain of events that lead to metastasis would provide mechanistically linked biomarkers for the maintenance of remission in CRC patients after curative treatment. We hypothesized, that Metastasis-associated in colorectal cancer-1 (MACC1) induces a secretory phenotype to enforce metastasis in a paracrine manner, and found, that the cell-free culture medium of MACC1-expressing CRC cells induces migration. Stable isotope labeling by amino acids in cell culture mass spectrometry (SILAC-MS) of the medium revealed, that S100A4 is significantly enriched in the MACC1-specific secretome. Remarkably, both biomarkers correlate in expression data of independent cohorts as well as within CRC tumor sections. Furthermore, combined elevated transcript levels of the metastasis genes MACC1 and S100A4 in primary tumors and in blood plasma robustly identifies CRC patients at high risk for poor metastasis-free (MFS) and overall survival (OS). Mechanistically, MACC1 strengthens the interaction of β-catenin with TCF4, thus inducing S100A4 synthesis transcriptionally, resulting in elevated secretion to enforce cell motility and metastasis. In cell motility assays, S100A4 was indispensable for MACC1-induced migration, as shown via knock-out and pharmacological inhibition of S100A4. The direct transcriptional and functional relationship of MACC1 and S100A4 was probed by combined targeting with repositioned drugs. In fact, the MACC1-β-catenin-S100A4 axis by statins (MACC1) and niclosamide (S100A4) synergized in inhibiting cancer cell motility in vitro and metastasis in vivo. The MACC1-β-catenin-S100A4 signaling axis is causal for CRC metastasis. Selectively repositioned drugs synergize in restricting MACC1/S100A4-driven metastasis with cross-entity potential.

DNA Methylation Biomarkers in Colorectal Cancer: Clinical Applications for Precision Medicine

Colorectal cancer (CRC) is the second leading cause of cancer death worldwide that is attributed to gradual long-term accumulation of both genetic and epigenetic changes. To reduce the mortality rate of CRC and to improve treatment efficacy, it will be important to develop accurate noninvasive diagnostic tests for screening, acute, and personalized diagnosis. Epigenetic changes such as DNA methylation play an important role in the development and progression of CRC. Over the last decade, a panel of DNA methylation markers has been reported showing a high accuracy and reproducibility in various semi-invasive or noninvasive biosamples. Research to obtain comprehensive panels of markers allowing a highly sensitive and differentiating diagnosis of CRC is ongoing. Moreover, the epigenetic alterations for cancer therapy, as a precision medicine strategy will increase their therapeutic potential over time. Here, we discuss the current state of DNA methylation-based biomarkers and their impact on CRC diagnosis. We emphasize the need to further identify and stratify methylation-biomarkers and to develop robust and effective detection methods that are applicable for a routine clinical setting of CRC diagnostics particularly at the early stage of the disease.

Acoustic Bioprinting of Patient-Derived Organoids for Predicting Cancer Therapy Responses

Cancer models, which are biologically representative of patient tumors, can predict the treatment responses and help determine the most appropriate cancer treatment for individual patients. Here, a point-of-care testing system called acoustically bioprinted patient-derived microtissues (PDMs) that can model cancer invasion and predict treatment response in individual patients with colorectal cancer (CRC), is reported. The PDMs are composed of patient-derived colorectal tumors and healthy organoids which can be precisely arranged by acoustic bioprinting approach for recapulating primary tissue's architecture. Particularly, these tumor organoids can be efficiently generated and can apprehend histological, genomic, and phenotypical characteristics of primary tumors. Consequently, these PDMs allow physiologically relevant in vitro drug (5-fluorouracil) screens, thus predicting the paired patient's responses to chemotherapy. A correlation between organoid invasion speed and normalized spreading speed of the paired patients is further established. It provides a quantitative indicator to help doctors make better decisions on ultimate anus-preserving operation for extremely low CRC patients. Thus, by combing acoustic bioprinting and organoid cultures, this method may open an avenue to establish complex 3D tissue models for precision and personalized medicine.

In Vivo and In Vitro Enhanced Tumoricidal Effects of Metformin, Active Vitamin D3, and 5-Fluorouracil Triple Therapy against Colon Cancer by Modulating the PI3K/Akt/PTEN/mTOR Network

Simple Summary

Failure of chemotherapy is common during the treatment of colon cancer, and there is a compelling need to develop alternative therapeutic approaches against this common malignancy. Metformin, which is an oral hypoglycaemic agent used for treating diabetes mellitus, and vitamin D have shown promising anticancer activities, and both agents boosted the actions of chemotherapy against colon cancer. This study, therefore, measured the potential beneficial effects of adding metformin and/or active vitamin D to the main cytotoxic drug used for treating colon cancer. The results demonstrate that metformin had superior anticancer effects relative to active vitamin D and ameliorated the effects of chemotherapy in animals and in cells. To the best of our knowledge, this study is also the first to report that triple treatment with the drugs of interest showed the best inhibition of cancer progression, which could provide a better therapeutic strategy against colon cancer.

Abstract

Chemoresistance to 5-fluorouracil (5-FU) is common during colorectal cancer (CRC) treatment. This study measured the chemotherapeutic effects of 5-FU, active vitamin D₃ (VD₃), and/or metformin single/dual/triple regimens as complementary/alternative therapies. Ninety male mice were divided into: negative and positive (PC) controls, and 5-FU, VD₃, Met, 5-FU/VD₃, 5-FU/Met, VD₃/Met, and 5-FU/VD₃/Met groups. Treatments lasted four weeks following CRC induction by azoxymethane. Similar regimens were also applied in the SW480 and SW620 CRC cell lines. The PC mice had abundant tumours, markedly elevated proliferation markers (survivin/CCND1) and PI3K/Akt/mTOR, and reduced p21/PTEN/cytochrome C/caspase-3 and apoptosis. All therapies reduced tumour numbers, with 5-FU/VD₃/Met being the most efficacious regimen. All protocols decreased cell proliferation markers, inhibited PI3K/Akt/mTOR molecules, and increased proapoptotic molecules with an apoptosis index, and 5-FU/VD₃/Met revealed the strongest effects. In vitro, all therapies equally induced G1 phase arrest in SW480 cells, whereas metformin-alone showed maximal SW620 cell numbers in the G0/G1 phase. 5-FU/Met co-therapy also showed the highest apoptotic SW480 cell numbers (13%), whilst 5-FU/VD₃/Met disclosed the lowest viable SW620 cell percentages (81%). Moreover, 5-FU/VD₃/Met revealed maximal inhibitions of cell cycle inducers (CCND1/CCND3), cell survival (BCL2), and the PI3K/Akt/mTOR molecules alongside the highest expression of cell cycle inhibitors (p21/p27), proapoptotic markers (BAX/cytochrome C/caspase-3), and PTEN in both cell lines. In conclusion, metformin monotherapy was superior to VD₃, whereas the 5-FU/Met protocol showed better anticancer effects relative to the other dual therapies. However, the 5-FU/VD₃/Met approach displayed the best in vivo and in vitro tumoricidal effects related to cell cycle arrest and apoptosis, justifiably by enhanced modulations of the PI3K/PTEN/Akt/mTOR pathway.

Enhanced in vitro tumoricidal effects of 5-Fluorouracil, thymoquinone, and active vitamin D3 triple therapy against colon cancer cells by attenuating the PI3K/AKT/mTOR pathway

AIMS

This study measured the effects of 5-Fluorouracil (5-FU), calcitriol (VD₃), and/or thymoquinone (TQ) single/dual/triple therapies on cell cycle progression, apoptosis, inhibition of the PI3K/AKT/mTOR pathway, and oxidative stress against colorectal cancer (CRC).

MAIN METHODS

The HT29, SW480 and SW620 cell lines were treated with 5-FU (50 μM), VD₃ (25 μM), and TQ (75 μM), alone or combined for 12 h, prior to cell cycle/apoptosis analyses.

KEY FINDINGS

TQ monotherapy had greater anticancer effects to active VD₃ or 5-FU, revealing higher expression of p21/p27/PTEN/BAX/Cyto-C/Casp-3 and increased levels of total glutathione, with inhibitions in CCND1/CCND3/BCL-2 and PI3K/AKT/mTOR molecules, alongside higher rates of apoptosis in HT29, SW480 and SW620 cells (P < 0.005 for all markers). Additionally, all combination protocols revealed enhanced modulations of the PI3K/PTEN/Akt/mTOR pathway, higher expression of p21/p27/PTEN/BAX/Cyto-C/Casp-3, and better anti-oxidant effects, than the monotherapies. Although TQ/5-FU and TQ/VD₃ co-therapies were better relative to the VD₃/5-FU regimen, the best tumoricidal effects were observed with triple therapy in the HT29 and SW480 cell lines, possibly by boosted attenuations of the PI3K/AKT/mTOR oncogenic pathway. In contrast, TQ single treatment was more effective than the triple therapy regimen in metastatic SW620 cells, suggesting that this protocol would be more useful therapeutically in late-stage CRC.

SIGNIFICANCE

In conclusion, this study is the first to demonstrated enhanced anti-tumorigenic effects for VD₃, TQ, and 5-FU triple therapy against CRC cells and could represent the best strategy for treating early stages of malignancy, whereas TQ monotherapy could be a better approach for treating metastatic forms of the disease.

Contribution of Epithelial and Gut Microbiome Inflammatory Biomarkers to the Improvement of Colorectal Cancer Patients’ Stratification

In order to ensure that primary endpoints of clinical studies are attained, the patients’ stratification is an important aspect. Selection criteria include age, gender, and also specific biomarkers, such as inflammation scores. These criteria are not sufficient to achieve a straightforward selection, however, in case of multifactorial diseases, with unknown or partially identified mechanisms, occasionally including host factors, and the microbiome. In these cases, the efficacy of interventions is difficult to predict, and as a result, the selection of subjects is often random. Colorectal cancer (CRC) is a highly heterogeneous disease, with variable clinical features, outcomes, and response to therapy; the CRC onset and progress involves multiple sequential steps with accumulation of genetic alterations, namely, mutations, gene amplification, and epigenetic changes. The gut microbes, either eubiotic or dysbiotic, could influence the CRC evolution through a complex and versatile crosstalk with the intestinal and immune cells, permanently changing the tumor microenvironment. There have been significant advances in the development of personalized approaches for CRC screening, treatment, and potential prevention. Advances in molecular techniques bring new criteria for patients’ stratification—mutational analysis at the time of diagnosis to guide treatment, for example. Gut microbiome has emerged as the main trigger of gut mucosal homeostasis. This may impact cancer susceptibility through maintenance of the epithelial/mucus barrier and production of protective metabolites, such as short-chain fatty acids (SCFAs) via interactions with the hosts’ diet and metabolism. Microbiome dysbiosis leads to the enrichment of cancer-promoting bacterial populations, loss of protective populations or maintaining an inflammatory chronic state, all of which contribute to the development and progression of CRC. Meanwhile, variations in patient responses to anti-cancer immuno- and chemotherapies were also linked to inter-individual differences in intestine microbiomes. The authors aim to highlight the contribution of epithelial and gut microbiome inflammatory biomarkers in the improvement of CRC patients’ stratification towards a personalized approach of early diagnosis and treatment.

Identification of a 3-gene signature for predicting the prognosis of stage II colon cancer based on microsatellite status

Background

Though colon cancer (CC) is one of the most malignant tumors across the world, CC patients with microsatellite instability-high (MSI-H) in stage II seem to have a better prognosis. However, the molecular mechanisms underlying the phenomena haven't been elucidated yet.

Methods

This study enrolled 322 CCs with known microsatellite status from GSE143985, GSE39582 and GSE92921 in the Gene Expression Omnibus (GEO) database. Robust rank aggregation (RRA) analysis, univariate Cox regression analysis and multivariate Cox stepwise regression analysis were performed to identify genes and construct risk score signature. Kaplan-Meier and receiver operating characteristic (ROC) curves analyses were used to evaluate the prognostic value of the signature. The potential mechanisms underlying this signature were assessed in the Metascape database, gene set enrichment analysis (GSEA) and immune infiltration analysis.

Results

RRA analysis identified 40 differently expressed genes (DEGs). A 3-gene risk score signature (MKQ signature) associated with disease-free survival (DFS) was generated. DFS was significantly longer in CC patients with lower than higher scores (P=0.0046). The areas under curves (AUCs) of the time-dependent ROC curves of MKQ signature at 1-, 3- and 5-year DFS were 1, 0.963 and 0.961 respectively. Recurrence-free survival (RFS) was significantly longer in patients in GSE39582 with lower than higher risk scores (P=0.032). The AUCs for 1-, 3- and 5-year RFS in GSE39582 were 0.63, 0.618 and 0.583, respectively, validating the value of the MKQ signature. Functional annotation and GSEA revealed that the MKQ signature was associated with multiple immune-related pathways. Immune cell infiltration was found to differ in patients differing in the MKQ signature.

Conclusions

Gene expression and microsatellite status identified a 3-gene signature (MKQ signature) that could facilitate risk-stratified management in patients with stage II CC. Dysregulation of MSMB, KRT23, and QPRT can serve as prognostic markers in stage II CC.

Enhanced anti-cancer effects of oestrogen and progesterone co-therapy against colorectal cancer in males

Although ovarian sex steroids could have protective roles against colorectal cancer (CRC) in women, little is currently known about their potential anti-tumorigenic effects in men. Hence, this study measured the therapeutic effects of 17β-oestradiol (E2) and/or progesterone (P4) against azoxymethane-induced CRC in male mice that were divided into (n = 10 mice/group): negative (NC) and positive (PC) controls, E2 (580 µg/Kg/day; five times/week) and P4 (2.9 mg/Kg/day; five times/week) monotherapies, and concurrent (EP) and sequential (E/P) co-therapy groups. Both hormones were injected intraperitoneally to the designated groups for four consecutive weeks. Similar treatment protocols with E2 (10 nM) and/or P4 (20 nM) were also used in the SW480 and SW620 human male CRC cell lines. The PC group showed abundant colonic tumours alongside increased colonic tissue testosterone levels and androgen (AR) and oestrogen (ERα) receptors, whereas E2 and P4 levels with ERβ and progesterone receptor (PGR) decreased significantly compared with the NC group. E2 and P4 monotherapies equally increased ERβ/PGR with p21/Cytochrome-C/Caspase-3, reduced testosterone levels, inhibited ERα/AR and CCND1/survivin and promoted apoptosis relative to the PC group. Both co-therapy protocols also revealed better anti-cancer effects with enhanced modulation of colonic sex steroid hormones and their receptors, with E/P the most prominent protocol. In vitro, E/P regimen showed the highest increases in the numbers of SW480 (2.1-fold) and SW620 (3.5-fold) cells in Sub-G1 phase of cell cycle. The E/P co-therapy also disclosed the lowest percentages of viable SW480 cells (2.8-fold), whilst both co-therapy protocols equally showed the greatest SW620 apoptotic cell numbers (5.2-fold) relative to untreated cells. Moreover, both co-therapy regimens revealed maximal inhibitions of cell cycle inducers, cell survival markers, and AR/ERα alongside the highest expression of cell cycle suppressors, pro-apoptotic molecules, and ERβ/PGR in both cell lines. In conclusion, CRC was associated with abnormal levels of colonic sex steroid hormones alongside aberrant protein expression of their receptors. While the anti-cancer effects of E2 and P4 monotherapies were equal, their combination protocols showed boosted tumoricidal actions against CRC in males, possibly by promoting ERβ and PGR-mediated androgen deprivation together with inhibition of ERα-regulated oncogenic pathways.

Untargeted GC-MS-Based Metabolomics for Early Detection of Colorectal Cancer

BACKGROUND

Colorectal cancer (CRC) is one of the most common malignant gastrointestinal cancers in the world with a 5-year survival rate of approximately 68%. Although researchers accumulated many scientific studies, its pathogenesis remains unclear yet. Detecting and removing these malignant polyps promptly is the most effective method in CRC prevention. Therefore, the analysis and disposal of malignant polyps is conducive to preventing CRC.

METHODS

In the study, metabolic profiling as well as diagnostic biomarkers for CRC was investigated using untargeted GC-MS-based metabolomics methods to explore the intervention approaches. In order to better characterize the variations of tissue and serum metabolic profiles, orthogonal partial least-square discriminant analysis was carried out to further identify significant features. The key differences in tR-m/z pairs were screened by the S-plot and VIP value from OPLS-DA. Identified potential biomarkers were leading in the KEGG in finding interactions, which show the relationships among these signal pathways.

RESULTS

Finally, 17 tissue and 13 serum candidate ions were selected based on their corresponding retention time, p-value, m/z, and VIP value. Simultaneously, the most influential pathways contributing to CRC were inositol phosphate metabolism, primary bile acid biosynthesis, phosphatidylinositol signaling system, and linoleic acid metabolism.

CONCLUSIONS

The preliminary results suggest that the GC-MS-based method coupled with the pattern recognition method and understanding these cancer-specific alterations could make it possible to detect CRC early and aid in the development of additional treatments for the disease, leading to improvements in CRC patients' quality of life.

Implications of Intratumor Heterogeneity on Consensus Molecular Subtype (CMS) in Colorectal Cancer

The implications of intratumor heterogeneity on the four consensus molecular subtypes (CMS) of colorectal cancer (CRC) are not well known. Here, we use single-cell RNA sequencing (scRNASeq) to build an algorithm to assign CMS classification to individual cells, which we use to explore the distributions of CMSs in tumor and non-tumor cells. A dataset of colorectal tumors with bulk RNAseq (n = 3232) was used to identify CMS specific-marker gene sets. These gene sets were then applied to a discovery dataset of scRNASeq profiles (n = 10) to develop an algorithm for single-cell CMS (scCMS) assignment, which recapitulated the intrinsic biology of all four CMSs. The single-cell CMS assignment algorithm was used to explore the scRNASeq profiles of two prospective CRC tumors with mixed CMS via bulk sequencing. We find that every CRC tumor contains individual cells of each scCMS, as well as many individual cells that have enrichment for features of more than one scCMS (called mixed cells). scCMS4 and scCMS1 cells dominate stroma and immune cell clusters, respectively, but account for less than 3% epithelial cells. These data imply that CMS1 and CMS4 are driven by the transcriptomic contribution of immune and stromal cells, respectively, not tumor cells.

Yap-Hippo Signaling Activates Mitochondrial Protection and Sustains Breast Cancer Viability under Hypoxic Stress

Yes-associated protein (Yap) is a transcriptional regulator that upregulates oncogenes and downregulates tumor repressor genes. In this study, we analyzed protein expression, RNA transcription, and signaling pathways to determine the function and mechanism of Yap in breast cancer survival during hypoxic stress. Yap transcription was drastically upregulated by hypoxia in a time-dependent manner. siRNA-mediated Yap knockdown attenuated breast cancer viability and impaired cell proliferation under hypoxic conditions. Yap knockdown induced mitochondrial stress, including mitochondrial membrane potential reduction, mitochondrial oxidative stress, and ATP exhaustion after exposure to hypoxia. It also repressed mitochondrial protective systems, including mitophagy and mitochondrial fusion upon exposure to hypoxia. Finally, our data showed that Yap knockdown suppresses MCF-7 cell migration by inhibiting F-actin transcription and promoting lamellipodium degradation under hypoxic stress. Taken together, Yap maintenance of mitochondrial function and activation of F-actin/lamellipodium signaling is required for breast cancer survival, migration, and proliferation under hypoxic stress.

Construction and Comprehensive Prognostic Analysis of a lncRNA-miRNA-mRNA Regulatory Network and Tumor Immune Cell Infiltration in Colorectal Cancer

Colorectal cancer (CRC) is a malignant tumor with high morbidity and mortality worldwide. Recent studies have shown that long noncoding RNAs (lncRNAs) play an important role in almost all human tumors, including CRC. Competitive endogenous RNA (ceRNA) regulatory networks have become hot topics in cancer research. Tumor-infiltrating immune cells (TICs) have also been reported to be closely related to the survival and prognosis of CRC patients. In this study, we used the lncRNA–miRNA–mRNA regulatory network combined with tumor immune cell infiltration to predict the survival and prognosis of 598 CRC patients. First, we downloaded the lncRNA, mRNA, and miRNA transcriptome data of CRC patients from The Cancer Genome Atlas (TCGA) database and identified differentially expressed genes through “limma” package of R software. The ceRNA regulatory network was established by using the “GDCRNATools” R package. Then, univariate Cox analysis and least absolute shrinkage and selection operator analysis were performed to identify the optimal prognostic network nodes, including SRPX, UST, H19, SNHG7, hsa-miR-29b-3p, and TTYH3. Next, we analyzed the differences in 22 types of TICs between 58 normal subjects and 206 CRC patients and included memory CD4 T cells, dendritic cells and neutrophils in the construction of a prognostic model. Finally, we identified the relationship between the ceRNA prognostic model and the infiltrating immune cell prognostic model. In conclusion, we constructed two prognostic models that provide insights on the prognosis and treatment strategy of CRC.

Identifying Novel Actionable Targets in Colon Cancer

Colorectal cancer is the fourth cause of death from cancer worldwide, mainly due to the high incidence of drug-resistance toward classic chemotherapeutic and newly targeted drugs. In the last decade or so, the development of novel high-throughput approaches, both genome-wide and chemical, allowed the identification of novel actionable targets and the development of the relative specific inhibitors to be used either to re-sensitize drug-resistant tumors (in combination with chemotherapy) or to be synthetic lethal for tumors with specific oncogenic mutations. Finally, high-throughput screening using FDA-approved libraries of “known” drugs uncovered new therapeutic applications of drugs (used alone or in combination) that have been in the clinic for decades for treating non-cancerous diseases (re-positioning or re-purposing approach). Thus, several novel actionable targets have been identified and some of them are already being tested in clinical trials, indicating that high-throughput approaches, especially those involving drug re-positioning, may lead in a near future to significant improvement of the therapy for colon cancer patients, especially in the context of a personalized approach, i.e., in defined subgroups of patients whose tumors carry certain mutations.

The diagnostic accuracy of digital PCR, ARMS and NGS for detecting KRAS mutation in cell-free DNA of patients with colorectal cancer: A systematic review and meta-analysis

Introduction

Before anti-EGFR therapy is given to patients with colorectal cancer, it is required to determine KRAS mutation status in tumor. When tumor tissue is not available, cell-free DNA (liquid biopsy) is commonly used as an alternative. Due to the low abundance of tumor-derived DNA in cell-free DNA samples, methods with high sensitivity were preferred, including digital polymerase chain reaction, amplification refractory mutation system and next-generation sequencing. The aim of this systemic review and meta-analysis was to investigate the accuracy of those methods in detecting KRAS mutation in cell-free DNA sample from patients with colorectal cancer.

Methods

Literature search was performed in Pubmed, Embase, and Cochrane Library. After removing duplicates from the 170 publications found by literature search, eligible studies were identified using pre-defined criteria. Quality of the publications and relevant data were assessed and extracted thereafter. Meta-DiSc and STATA softwares were used to pool the accuracy parameters from the extracted data.

Results

A total of 33 eligible studies were identified for this systemic review and meta-analysis. After pooling, the overall sensitivity, specificity, and diagnostic odds ratio were 0.77 (95%CI: 0.74–0.79), 0.87 (95%CI: 0.85–0.89), and 23.96 (95%CI: 13.72–41.84), respectively. The overall positive and negative likelihood ratios were 5.55 (95%CI: 3.76–8.19) and 0.29 (95%CI: 0.21–0.38), respectively. Area under curve of the summarized ROC curve was 0.8992.

Conclusion

Digital polymerase chain reaction, amplification refractory mutation system, and next-generation sequencing had overall high accuracy in detecting KRAS mutation in cell-free DNA sample. Large prospective randomized clinical trials are needed to further convince the accuracy and usefulness of KRAS mutation detection using cfDNA/liquid biopsy samples in clinical practice.

Trial registration

PROSPERO CRD42020176682; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=176682.

The Roadmap of Colorectal Cancer Screening

Colorectal cancer (CRC) is the third most common form of cancer in terms of incidence and the second in terms of mortality worldwide. CRC develops over several years, thus highlighting the importance of early diagnosis. National screening programs based on fecal occult blood tests and subsequent colonoscopy have reduced the incidence and mortality, however improvements are needed since the participation rate remains low and the tests present a high number of false positive results. This review provides an overview of the CRC screening globally and the state of the art in approaches aimed at improving accuracy and participation in CRC screening, also considering the need for gender and age differentiation. New fecal tests and biomarkers such as DNA methylation, mutation or integrity, proteins and microRNAs are explored, including recent investigations into fecal microbiota. Liquid biopsy approaches, involving novel biomarkers and panels, such as circulating mRNA, micro- and long-non-coding RNA, DNA, proteins and extracellular vesicles are discussed. The approaches reported are based on quantitative PCR methods that could be easily applied to routine screening, or arrays and sequencing assays that should be better exploited to describe and identify candidate biomarkers in blood samples.

Subversion of Niche-Signalling Pathways in Colorectal Cancer: What Makes and Breaks the Intestinal Stem Cell

The intestinal epithelium fulfils pleiotropic functions in nutrient uptake, waste elimination, and immune surveillance while also forming a barrier against luminal toxins and gut-resident microbiota. Incessantly barraged by extraneous stresses, the intestine must continuously replenish its epithelial lining and regenerate the full gamut of specialized cell types that underpin its functions. Homeostatic remodelling is orchestrated by the intestinal stem cell (ISC) niche: a convergence of epithelial- and stromal-derived cues, which maintains ISCs in a multipotent state. Following demise of homeostatic ISCs post injury, plasticity is pervasive among multiple populations of reserve stem-like cells, lineage-committed progenitors, and/or fully differentiated cell types, all of which can contribute to regeneration and repair. Failure to restore the epithelial barrier risks seepage of toxic luminal contents, resulting in inflammation and likely predisposing to tumour formation. Here, we explore how homeostatic niche-signalling pathways are subverted in tumorigenesis, enabling ISCs to gain autonomy from niche restraints ("ISC emancipation") and transform into cancer stem cells capable of driving tumour initiation, progression, and therapy resistance. We further consider the implications of the pervasive plasticity of the intestinal epithelium for the trajectory of colorectal cancer, the emergence of distinct molecular subtypes, the propensity to metastasize, and the development of effective therapeutic strategies.

Chemopreventive effects of vitamin D3 and its analogue, paricalcitol, in combination with 5-fluorouracil against colorectal cancer: The role of calcium signalling molecules

BACKGROUND

Although vitamin D (VD) is chemoprotective and enhances 5-fluorouracil (5-FU) cytotoxicity against colorectal cancer (CRC), little is known about its potential calcium (Ca²⁺)-mediated anti-tumorigenic actions. Therefore, this study compared between VD and its non-calcaemic analogue, Paricalcitol (Pcal), ± 5-FU in relation to chemoprevention and Ca²⁺-mediated apoptosis in vivo and in vitro.

METHODS

Seventy male mice were distributed to: negative controls, positive controls (PC), VD, Pcal, 5-FU, VD + 5-FU and Pcal+5-FU groups. All groups, except negative, received two consecutive azoxymethane (AOM)-injections (10 mg/Kg/week) for CRC induction. VD₃ (1000 IU/kg; three times/week) and Pcal (1.25 μg/kg; three times/week) injections started week-16 post-AOM and for 10 weeks. Three successive 5-FU cycles began at week-21 (50 mg/Kg/week). Similar protocols with VD₃, Pcal and/or 5-FU were applied in the HT29 colon cancer cells.

RESULTS

The PC group had abundant malignant tumours, markedly elevated proliferation markers (survivin/CCND1) and declines in cyclin-dependent kinase-inhibitor-1A, pro-apoptotic molecules (p53/BAX/cytochrome_C/caspase-3), tissue Ca²⁺ concentrations and Ca²⁺-dependent proteins (CaSR/CAM/CAMKIIA). All monotherapies equally reduced tumour numbers and proliferation markers whilst promoting the anti-tumorigenic molecules. VD and/or 5-FU, but not Pcal monotherapy, enhanced Ca²⁺ levels and Ca²⁺-related molecules (CaSR/CAM/CAMKIIA/BAX/cytochrome_C) in vivo and in vitro. However, VD + 5-FU co-therapy showed the lowest tumour numbers, the highest cell numbers in sub-G1 phase of cell cycle, alongside the most effective modulations of oncogenes, tumour suppressors and Ca²⁺-related molecules at the gene and protein levels in vivo and in vitro.

CONCLUSIONS

VD₃ was superior than Paricalcitol in potentiating 5-FU cytotoxicity, possibly by upregulating several Ca²⁺-related molecules involved in tumour suppression.

Emerging roles for HMGA2 in colorectal cancer

HMGA2 (High Mobility Group AT-hook 2) has been reported to promote colorectal cancer (CRC) development by regulating the transcription of target genes. It participates in nearly all aspects of cellular processes, including cell transformation, proliferation, apoptosis, senescence, metastasis, epithelial-to-mesenchymal transition (EMT), DNA repair and stem cell self-renewal. In the past decades, a group of downstream targets and binding partners have been identified in a wide range of cancers. Our findings of HMGA2 as a key factor in the MDM2/p53, IL11/STAT3 and Wnt/β-catenin signaling pathways prompt us to summarize current advances in the functional and molecular basis of HMGA2 in CRC. In this review, we address the roles of HMGA2 in the oncogenic networks of CRC based on recent advances. We review its aberrant expression, explore underlying mechanisms, discuss its pro-tumorigenic effects, and highlight promising small-molecule inhibitors based on targeting HMGA2 here. However, the understanding of HMGA2 in CRC progression is still elusive, thus we also discuss the future perspectives in this review. Collectively, this review provides novel insights into the oncogenic properties of HMGA2, which has potential implications in the diagnosis and treatment of CRC.

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HMGA2 promotes colorectal cancer (CRC) development by regulating the transcriptions of target genes.

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Circulating cell-free HMGA2 mRNA has been identified as a potential screening marker in CRC.

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HMGA2 appears to be a key factor in the networks of MDM2/p53, IL11/STAT3 and Wnt/β-catenin signaling pathways in CRC.

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Many agents and siRNAs serve as potential therapeutic approaches by targeting HMGA2 for the treatment of CRC.

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Deciphering HMGA2-mediated machinery helps to conceive effective therapy strategies and develop novel inhibitors in CRC.

Biomarkers in Colorectal Cancer: Current Research and Future Prospects

Colorectal cancer (CRC) is a leading cause of death worldwide, despite progress made in detection and management through surgery, chemotherapy, radiotherapy, and immunotherapy. Novel therapeutic agents have improved survival in both the adjuvant and advanced disease settings, albeit with an increased risk of toxicity and cost. However, metastatic disease continues to have a poor long-term prognosis and significant challenges remain due to late stage diagnosis and treatment failure. Biomarkers are a key tool in early detection, prognostication, survival, and predicting treatment response. The past three decades have seen advances in genomics and molecular pathology of cancer biomarkers, allowing for greater individualization of therapy with a positive impact on survival outcomes. Clinically useful predictive biomarkers aid clinical decision making, such as the presence of KRAS gene mutations predicting benefit from epidermal growth factor receptor (EGFR) inhibiting antibodies. However, few biomarkers have been translated into clinical practice highlighting the need for further investigation. We review a range of protein, DNA and RNA-based biomarkers under investigation for diagnostic, predictive, and prognostic properties for CRC. In particular, long non-coding RNAs (lncRNA), have been investigated as biomarkers in a range of cancers including colorectal cancer. Specifically, we evaluate the potential role of lncRNA plasmacytoma variant translocation 1 (PVT1), an oncogene, as a diagnostic, prognostic, and therapeutic biomarker in colorectal cancer.

The diagnostic accuracy of digital PCR, ARMS and NGS for detecting KRAS mutation in cell-free DNA of patients with colorectal cancer: A protocol for systematic review and meta-analysis

INTRODUCTION

Cetuximab and panitumumab have been used clinically to treat metastatic colorectal cancer for more than 15 years. Before the treatment is given, it is required to determine the KRAS mutation status since it would lead to drug resistance. Tumor tissue sample is traditionally used for cancer genotyping. In recent years, liquid biopsy sample has been intensively investigated as a surrogate for tumor tissue sample due to its non-invasiveness and better presentation of tumor heterogeneity. The aim of this study is to systematically summarize the accuracy of KRAS mutation measurement in colorectal cancer using cell-free DNA in liquid biopsy samples, with tumor tissue sample as reference (gold standard).

METHODS AND ANALYSIS

We will search literatures in the following databases: Pubmed, Embase, and Cochrane Library. Systemic review and meta-analysis will be performed to summarize the accuracy of KRAS mutation measurement in colorectal cancer using liquid biopsy sample, and subgroup analysis will be performed on different testing platforms, and on metastatic and non-metastatic colorectal cancer.

TIMELINE

This study will start on June 1, 2020, and is expected to be finished by November 1, 2020.

ETHICS AND DISSEMINATION

Ethical approval will not be required since the data obtained and analyzed in this study will not be on individual patients. Study results will be disseminated as an official publication in a peer-reviewed journal.Registration: PROSPERO CRD42020176682.