Prognostic role and clinicopathological features of SMAD4 gene mutation in colorectal cancer: a systematic review and meta-analysis

Challenges and Opportunities for Precision Surgery for Colorectal Liver Metastases

The incidence of colorectal cancer and colorectal liver metastases (CRLM) is increasing globally due to an interaction of environmental and genetic factors. A minority of patients with CRLM have surgically resectable disease, but for those who have resection as part of multimodal therapy for their disease, long-term survival has been shown. Precision surgery-the idea of careful patient selection and targeting of surgical intervention, such that treatments shown to be proven to benefit on a population level are the optimal treatment for each individual patient-is the new paradigm of care. Key to this is the understanding of tumour molecular biology and clinically relevant mutations, such as KRAS, BRAF, and microsatellite instability (MSI), which can predict poorer overall outcomes and a poorer response to systemic therapy. The emergence of immunotherapy and hepatic artery infusion (HAI) pumps show potential to convert previously unresectable disease to resectable disease, in addition to established systemic and locoregional therapies, but the surgeon must be wary of poor-quality livers and the spectre of post-hepatectomy liver failure (PHLF). Volume modulation, a cornerstone of hepatic surgery for a generation, has been given a shot in the arm with the advent of liver venous depletion (LVD) ensuring significantly more hypertrophy of the future liver remnant (FLR). The optimal timing of liver resection for those patients with synchronous disease is yet to be truly established, but evidence would suggest that those patients requiring complex colorectal surgery and major liver resection are best served with a staged approach. In the operating room, parenchyma-preserving minimally invasive surgery (MIS) can dramatically reduce the surgical insult to the patient and lead to better perioperative outcomes, with quicker return to function.

Genomic and Transcriptomic Analysis of a Patient with Early-Onset Colorectal Cancer and Therapy-Induced Focal Nodular Hyperplasia: A Case Report

Early-onset colorectal cancer (EOCRC), defined as colorectal cancer in individuals under 50 years of age, has shown an alarming increase in incidence worldwide. We report a case of a twenty-four-year-old female with a strong family history of colorectal cancer (CRC) but without an identified underlying genetic predisposition syndrome. Two years after primary surgery and adjuvant chemotherapy, the patient developed new liver lesions. Extensive diagnostic imaging was conducted to investigate suspected liver metastases, ultimately leading to a diagnosis of focal nodular hyperplasia. The young age of the patient has prompted comprehensive genomic and transcriptomic profiling in order to identify potential oncogenic drivers and inform further clinical management of the patient. Besides a number of oncogenic mutations identified in the patient's tumour sample, including KRAS G12D, TP53 R248W and TTN L28470V, we have also identified a homozygous deletion of 24.5 MB on chromosome 8. A multivariate Cox regression analysis of this patient's mutation profile conferred a favourable prognosis when compared with the TCGA COADREAD database. Notably, the identified deletion on chromosome 8 includes the WRN gene, which could contribute to the patient's overall positive response to chemotherapy. The complex clinical presentation, including the need for emergency surgery, early age at diagnosis, strong family history, and unexpected findings on surveillance imaging, necessitated a multidisciplinary approach involving medical, radiation, and surgical oncologists, along with psychological support and reproductive medicine specialists. Molecular profiling of the tumour strongly indicates that patients with complex mutational profile and rare genomic rearrangements require a prolonged surveillance and personalised informed interventions.

Biomarker Profile of Colorectal Cancer: Current Findings and Future Perspective

OBJECTIVE

Breakthroughs in omics technology have led to a deeper understanding of the fundamental molecular changes that play a critical role in the development and progression of cancer. This review delves into the hidden molecular drivers of colorectal cancer (CRC), offering potential for clinical translation through novel biomarkers and personalized therapies.

METHODS

We summarizes recent studies utilizing various omics approaches, including genomics, transcriptomics, proteomics, epigenomics, metabolomics and data integration with computational algorithms, to investigate CRC.

RESULTS

Integrating multi-omics data in colorectal cancer research unlocks hidden biological insights, revealing new pathways and mechanisms. This powerful approach not only identifies potential biomarkers for personalized prognosis, diagnosis, and treatment, but also predicts patient response to specific therapies, while computational tools illuminate the landscape by deciphering complex datasets.

CONCLUSIONS

Future research should prioritize validating promising biomarkers and seamlessly translating them into clinical practice, ultimately propelling personalized CRC management to new heights.

Somatic Mutations in Surgically Treated Colorectal Liver Metastases: An Overview

Colorectal cancer is the second most common cause of cancer death in the United States, and up to half of patients develop colorectal liver metastases (CRLMs). Notably, somatic genetic mutations, such as mutations in RAS, BRAF, mismatch repair (MMR) genes, TP53, and SMAD4, have been shown to play a prognostic role in patients with CRLM. This review summarizes and appraises the current literature regarding the most relevant somatic mutations in surgically treated CRLM by not only reviewing representative studies, but also providing recommendations for areas of future research. In addition, advancements in genetic testing and an increasing emphasis on precision medicine have led to a more nuanced understanding of these mutations; thus, more granular data for each mutation are reviewed when available. Importantly, such knowledge can pave the way for precision medicine with the ultimate goal of improving patient outcomes.

Expanding CYLD protein in NF-κβ/TNF-α signaling pathway in response to Lactobacillus acidophilus in non-metastatic rectal cancer patients

The CYLD gene is a tumor suppressor, reduced in many cancers. Here, we aimed to investigate CYLD protein level and NF-κβ/TNF-α signaling pathway in rectal cancer patients with Lactobacillus acidophilus (L. acidophilus) consumption. One hundred ten patients with non-metastatic rectal cancer were randomly divided into L. acidophilus probiotic (500 mg, three times daily) and placebo groups for 13 weeks. The expression of CYLD, TNF-α, and NF-κB proteins and the genes involved in the NF-κβ/TNF-α pathway were evaluated using ELISA and qPCR techniques. The survival rate was measured after five years. Unlike the placebo group, the results showed a significant increase in the expression of CYLD protein and tumor suppressor genes, including FOXP3, ROR-γ, Caspase3, GATA3, T-bet, and a considerable decrease in the expression of NF-ҝβ and TNF-α proteins and oncogenes, including STAT3, 4, 5, 6, and SMAD 3, in the probiotic group. A higher overall survival rate was seen after L. acidophilus consumption compared to the placebo group (P < 0.05). L. acidophilus consumption can reduce inflammation factors by affecting CYLD protein and its downstream signaling pathways. A schematic plot of probiotic consumption Effects on the CYLD protein in regulating the NF-ĸβ signaling pathway in colorectal cancer. NF-ĸβ can be activated by canonical and noncanonical pathways, which rely on IκB degradation and p100 processing, respectively. In the canonical NF-κβ pathway, dimmers, such as p65/p50, are maintained in the cytoplasm by interacting with an IκBα protein. The binding of a ligand to a cell-surface receptor activates TRAF2, which triggers an IKK complex, containing -α, -β, -g, which phosphorylates IKK-β. It then phosphorylates IκB-α, leading to K48-ubiquitination and degradation of this protein. The p65/p50 protein freely enters the nucleus to turn on target genes. The non-canonical pathway is primarily involved in p100/RelB activation. It differs from the classical pathway in that only certain receptor signals activate this pathway. It proceeds through an IKK complex that contains two IKK-α subunits but not NEMO. Several materials including peptidoglycan, phorbol, myristate, acetate, and gram-positive bacteria such as probiotics inhibit NF-κB by inducing CYLD. This protein can block the canonical and noncanonical NF-κβ pathways by removing Lys-63 ubiquitinated chains from activated TRAFs, RIP, NEMO, and IKK (α, β, and γ). Moreover, TNF-α induces apoptosis by binding caspase-3 to FADD.

Genetic and nongenetic mechanisms for colorectal cancer evolution

The stepwise accumulation of key driver mutations is responsible for the development and malignant progression of colorectal cancer in primary sites. Genetic mouse model studies have revealed combinations of driver gene mutations that induce phenotypic changes in tumors toward malignancy. However, cancer evolution is regulated by not only genetic alterations but also nongenetic mechanisms. For example, certain populations of metastatic cancer cells show a loss of malignant characteristics even after the accumulation of driver mutations, and such cells are eliminated in a negative selection manner. Furthermore, a polyclonal metastasis model has recently been proposed, in which cell clusters consisting of genetically heterogeneous cells break off from the primary site, disseminate to distant organs, and develop into heterogenous metastatic tumors. Such nongenetic mechanisms for malignant progression have been elucidated using genetically engineered mouse models as well as organoid transplantation experiments. In this review article, we discuss the role of genetic alterations in the malignant progression of primary intestinal tumors and nongenetic mechanisms for negative selection and polyclonal metastasis, which we learned from model studies.

Liquid Biopsy by ctDNA in Liver Transplantation for Colorectal Cancer Liver Metastasis

INTRODUCTION

Colorectal cancer is a leading cause of cancer-related death worldwide. Metastatic liver disease develops in 50% of cases and drives patient outcomes. Although the ideal treatment for colorectal cancer liver metastases (CRLM) is resection, only a third of patients are suitable for this approach. Reports of liver transplantation in selected patients with unresectable CRLM have shown encouraging results compared to conventional forms of therapy. No study to date has examined the utility of liquid biopsy circulating tumor DNA (ctDNA) for evaluation of residual disease in this cohort of patients. We report a small series of liver transplantation in patients with CRLM in whom ctDNA was assessed peri-operatively.

METHODS

Five patients underwent liver transplantation for unresectable CRLM or liver failure following CRLM treatment from 2018 to 2022. Clinical data, cross-sectional imaging, and serum biomarkers including peri-operative ctDNA were reviewed from electronic medical records.

RESULTS

All patients are alive without radiologic evidence of disease at time of this publication. Median time of follow-up was 32 months (IQR 6.6-40 months). ctDNA was assessed before (4 patients) and after transplant (6 patients). One patient experienced a pulmonary recurrence that was resected, for whom pre-recurrence ctDNA was not available; the remaining patients have not experienced recurrence. Four patients are without evidence of ctDNA following transplant, and two demonstrate persistent ctDNA positivity post-transplant. Three of four patients with positive pre-transplant ctDNA remain ctDNA-negative post-transplant.

CONCLUSIONS

Liver transplantation for liver-confined unresectable CRLM is emerging as a valid surgical option in selected patients. The significance of liquid biopsy in this population remains elusive due to lack of data. The clearance of ctDNA after transplant in these patients with metastatic disease and despite their immunosuppression is notable. The significance and usefulness of liquid biopsy in patient selection, surveillance, and as an indication for treatment warrant further investigation.

Genomic landscape of locally advanced rectal adenocarcinoma: Comparison between before and after neoadjuvant chemoradiation and effects of genetic biomarkers on clinical outcomes and tumor response

PURPOSE

To explore genomic biomarkers in rectal cancer by performing whole-exome sequencing.

MATERIALS AND METHODS

Pre-chemoradiation (CRT) biopsy and post-CRT surgical specimens were obtained from 27 patients undergoing neoadjuvant CRT followed by definitive resection. Exomes were sequenced to a mean coverage of 30×. Somatic single-nucleotide variants (SNVs) and insertions/deletions (indels) were identified. Tumor mutational burden was defined as the number of SNVs or indels. Mutational signatures were extracted and fitted to COSMIC reference signatures. Tumor heterogeneity was quantified with a mutant-allele tumor heterogeneity (MATH) score. Genetic biomarkers and frequently occurred copy number alterations (CNAs) were compared between pre- and post-CRT specimens. Their associations with tumor regression grade (TRG) and clinical outcomes were explored.

RESULTS

Top five mutated genes were APC, TP53, NF1, KRAS, and NOTCH1 for pre-CRT samples and APC, TP53, NF1, CREBBP, and ATM for post-CRT samples. Several gene mutations including RUNX1, EGFR, and TP53 in pre-CRT samples showed significant association with clinical outcomes, but not with TRG. However, no such association was found in post-CRT samples. Discordance of driver mutation status was found between pre- and post-CRT samples. In tumor mutational burden analysis, higher number of SNVs or indels was associated with worse treatment outcomes. Six single-base substitution (SBS) signatures identified were SBS1, SBS30, SBS29, SBS49, SBS3, and SBS44. The MATH score decreased after CRT on paired analysis. Less than half of CNAs frequent in post-CRT samples were present in pre-CRT samples.

CONCLUSION

Pre- and post-CRT samples showed different genomic landscape. Potential genetic biomarkers of pre-CRT samples found in the current analysis call for external validation.

Impact of Primary Tumor Location and Genomic Alterations on Survival Following Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemoperfusion for Colorectal Peritoneal Metastases

BACKGROUND

Colorectal cancer leads to peritoneal metastases (CRPM) in 10% of cases. Cytoreductive surgery with hyperthermic intraperitoneal chemoperfusion (CRS-HIPEC) improves survival. Primary tumor location and abnormalities in RAS, BRAF, and mismatch repair/microsatellite stability (MMR/MSI) may affect post-CRS-HIPEC survival, but studies have not been consistent. We estimated the effects of primary tumor site and genomic alterations on post-CRS-HIPEC survival.

METHODS

This retrospective cohort study included CRS-HIPEC cases for CRPM at a high-volume center from 2001 to 2020. Next-generation sequencing and microsatellite testing defined the RAS, BRAF, and MMR/MSI genotypes. Adjusted effects of tumor sidedness and genomics on survival were evaluated using a multivariable Cox proportional hazards model. We analyzed these variables' effects on progression-free survival and the effects of immune checkpoint-inhibitors.

RESULTS

A total of 250 patients underwent CRS-HIPEC with testing for RAS, BRAF, and MMR/MSI; 50.8% of patients were RAS-mutated, 12.4% were BRAF-mutated, and 6.8% were deficient-MMR/MSI-high (dMMR/MSI-H). Genomic alterations predominated in right-sided cancers. After adjustment for comorbidities and oncological and perioperative variables, rectal origin [hazard ratio (HR) 1.9, p = 0.01], RAS mutation (HR 1.6, p = 0.01), and BRAF mutation (HR 1.7, p = 0.05) were associated with worse survival. RAS mutation was also associated with shorter progression-free survival (HR 1.6, p = 0.01 at 6 months post-operatively), and dMMR/MSI-H status was associated with superior survival (HR 0.3, p = 0.01 at 2 years). dMMR/MSI-H patients receiving immune checkpoint-inhibitors trended toward superior survival.

CONCLUSIONS

Rectal origin, RAS mutations, and BRAF mutations are each associated with poorer survival after CRS-HIPEC for CRPM. Patients with CRPM and dMMR/MSI-H status have superior survival. Further research should evaluate benefits of immune checkpoint-inhibitors in this subgroup.

Carbon-Based Nanomaterials as Drug Delivery Agents for Colorectal Cancer: Clinical Preface to Colorectal Cancer Citing Their Markers and Existing Theranostic Approaches

Colorectal cancer (CRC) is one of the universally established cancers with a higher incidence rate. Novel progression toward cancer prevention and cancer care among countries in transition should be considered seriously for controlling CRC. Hence, several cutting edge technologies are ongoing for high performance cancer therapeutics over the past few decades. Several drug-delivery systems of the nanoregime are relatively new in this arena compared to the previous treatment modes such as chemo- or radiotherapy to mitigate cancer. Based on this background, the epidemiology, pathophysiology, clinical presentation, treatment possibilities, and theragnostic markers for CRC were revealed. Since the use of carbon nanotubes (CNTs) for the management of CRC has been less studied, the present review analyzes the preclinical studies on the application of carbon nanotubes for drug delivery and CRC therapy owing to their inherent properties. It also investigates the toxicity of CNTs on normal cells for safety testing and the clinical use of carbon nanoparticles (CNPs) for tumor localization. To conclude, this review recommends the clinical application of carbon-based nanomaterials further for the management of CRC in diagnosis and as carriers or therapeutic adjuvants.

Correlation between SMADs and Colorectal Cancer Expression, Prognosis, and Immune Infiltrates

Background

In recent years, the incidence and mortality of colorectal cancer (CRC) are increasing, and the 5-year survival rate of advanced metastatic CRC is poor. Small mothers against decapentaplegic (SMAD) superfamily are intracellular signal transduction proteins associated with the development and prognosis of a variety of tumors. At present, no study has systematically analysed the relationship between SMADs and CRC.

Methods

Here, R3.6.3 was used to analyse the expression of SMADs in pan-cancer and CRC. Protein expression of SMADs were analysed by Human Protein Atlas (HPA). Gene expression profiling interactive analysis (GEPIA) was used to evaluate the correlation between SMADs and tumor stage in CRC. The effect of R language and GEPIA on prognosis was analysed. Mutation rates of SMADs in CRC were determined by cBioPortal, and potentially related genes were predicted using GeneMANIA. R analysis was used to correlate immune cell infiltration in CRC.

Results

Both SMAD1 and SMAD2 were found to be weakly expressed in CRC and correlated with the immune invasion level. SMAD1 was correlated with patient prognosis, and SMAD2 was correlated with tumor stage. SMAD3, SMAD4, and SMAD7 were all expressed at low levels in CRC and associated with a variety of immune cells. SMAD3 and SMAD4 proteins were also expressed at low levels, and SMAD4 had the highest mutation rate. SMAD5 and SMAD6 were overexpressed in CRC, and SMAD6 was also associated with patient overall survival (OS) and CD8+ T cells, macrophages, and neutrophils.

Conclusions

Our results reveal innovative and strong evidence that SMADs can be used as biomarkers for the treatment and prognosis of CRC.

Identifying predictive biomarkers of apatinib in third-line treatment of advanced colorectal cancer through comprehensive genomic profiling

Apatinib is a selective inhibitor of vascular endothelial growth factor receptor-2. Despite encouraging anticancer activity in different cancer types, some patients may not benefit from apatinib treatment. Herein, we characterized genomic profiles in colorectal cancer (CRC) patients to explore predictive biomarkers of apatinib at molecular level. We retrospectively recruited 19 CRC patients receiving apatinib as third-line treatment. Tissue samples before apatinib treatment were collected and subjected to genomic profiling using a targeted sequencing panel covering 520 cancer-related genes. After apatinib treatment, the patients achieved an objective response rate of 21% (4/19) and disease control rate of 57.9% (11/19). The median progression-free survival (PFS) and overall survival were 5 and 8.7 months, respectively. Genetic alterations were frequently identified in TP53 (95%), APC (53%), KRAS (53%) and PIK3CA (26%). Higher tumor mutation burden levels were significantly observed in patients harboring alterations in ERBB and RAS signaling pathways. Patients harboring FLT1 amplifications ( n = 3) showed significantly worse PFS than wild-type patients. Our study described molecular profiles in CRC patients receiving apatinib treatment and identified FLT1 amplification as a potential predictive biomarker for poor efficacy of apatinib. Further studies are warranted to validate the use of FLT1 amplification during apatinib treatment.

Multiomics of Colorectal Cancer Organoids Reveals Putative Mediators of Cancer Progression Resulting from SMAD4 Inactivation

The development of metastasis severely reduces the life expectancy of patients with colorectal cancer (CRC). Although loss of SMAD4 is a key event in CRC progression, the resulting changes in biological processes in advanced disease and metastasis are not fully understood. Here, we applied a multiomics approach to a CRC organoid model that faithfully reflects the metastasis-supporting effects of SMAD4 inactivation. We show that loss of SMAD4 results in decreased differentiation and activation of pro-migratory and cell proliferation processes, which is accompanied by the disruption of several key oncogenic pathways, including the TGFβ, WNT, and VEGF pathways. In addition, SMAD4 inactivation leads to increased secretion of proteins that are known to be involved in a variety of pro-metastatic processes. Finally, we show that one of the factors that is specifically secreted by SMAD4-mutant organoids─DKK3─reduces the antitumor effects of natural killer cells (NK cells). Altogether, our data provide new insights into the role of SMAD4 perturbation in advanced CRC.

Comprehensive Molecular Characterization of Gallbladder Carcinoma and Potential Targets for Intervention

PURPOSE

Gallbladder carcinoma (GBC) is an uncommon and aggressive disease, which remains poorly defined at a molecular level. Here, we aimed to characterize the molecular landscape of GBC and identify markers with potential prognostic and therapeutic implications.

EXPERIMENTAL DESIGN

GBC samples were analyzed using the MSK-IMPACT (Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets) platform (targeted NGS assay that analyzes 505 cancer-associated genes). Variants with therapeutic implications were identified using OncoKB database. The associations between recurrent genetic alterations and clinicopathologic characteristics (Fisher exact tests) or overall survival (univariate Cox regression) were evaluated. P values were adjusted for multiple testing.

RESULTS

Overall, 244 samples (57% primary tumors and 43% metastases) from 233 patients were studied (85% adenocarcinomas, 10% carcinomas with squamous differentiation, and 5% neuroendocrine carcinomas). The most common oncogenic molecular alterations appeared in the cell cycle (TP53 63% and CDKN2A 21%) and RTK_RAS pathways (ERBB2 15% and KRAS 11%). No recurrent structural variants were identified. There were no differences in the molecular landscape of primary and metastasis samples. Variants in SMAD4 and STK11 independently associated with reduced survival in patients with metastatic disease. Alterations considered clinically actionable in GBC or other solid tumor types (e.g., NTRK1 fusions or oncogenic variants in ERBB2, PIK3CA, or BRCA1/2) were identified in 35% of patients; 18% of patients with metastatic disease were treated off-label or enrolled in a clinical trial based on molecular findings.

CONCLUSIONS

GBC is a genetically diverse malignancy. This large-scale genomic analysis revealed alterations with potential prognostic and therapeutic implications and provides guidance for the development of targeted therapies.

Deregulated transcription factors and poor clinical outcomes in cancer patients

Transcription factors are a group of proteins, which possess DNA-binding domains, bind to DNA strands of promoters or enhancers, and initiate transcription of genes with cooperation of RNA polymerase and other co-factors. They play crucial roles in regulating transcription during embryogenesis and development. Their physiological status in different cell types is also important to maintain cellular homeostasis. Therefore, any deregulation of transcription factors will lead to the development of cancer cells and tumor progression. Based on their functions in cancer cells, transcription factors could be either oncogenic or tumor suppressive. Furthermore, transcription factors have been shown to modulate cancer stem cells, epithelial-mesenchymal transition (EMT) and drug response; therefore, measuring deregulated transcription factors is hypothesized to predict treatment outcomes of patients with cancers and targeting deregulated transcription factors could be an encouraging strategy for cancer therapy. Here, we summarize the current knowledge of major deregulated transcription factors and their effects on causing poor clinical outcome of patients with cancer. The information presented here will help to predict the prognosis and drug response and to design novel drugs and therapeutic strategies for the treatment of cancers by targeting deregulated transcription factors.

Transforming growth factor-β in tumour development

Transforming growth factor-β (TGFβ) is a ubiquitous cytokine essential for embryonic development and postnatal tissue homeostasis. TGFβ signalling regulates several biological processes including cell growth, proliferation, apoptosis, immune function, and tissue repair following injury. Aberrant TGFβ signalling has been implicated in tumour progression and metastasis. Tumour cells, in conjunction with their microenvironment, may augment tumourigenesis using TGFβ to induce epithelial-mesenchymal transition, angiogenesis, lymphangiogenesis, immune suppression, and autophagy. Therapies that target TGFβ synthesis, TGFβ-TGFβ receptor complexes or TGFβ receptor kinase activity have proven successful in tissue culture and in animal models, yet, due to limited understanding of TGFβ biology, the outcomes of clinical trials are poor. Here, we review TGFβ signalling pathways, the biology of TGFβ during tumourigenesis, and how protein quality control pathways contribute to the tumour-promoting outcomes of TGFβ signalling.

Targeted Next-Generation Sequencing-Based Multiple Gene Mutation Profiling of Patients with Rectal Adenocarcinoma Receiving or Not Receiving Neoadjuvant Chemoradiotherapy

This study investigated whether oncogenic and tumor-suppressive gene mutations are involved in the differential outcomes of patients with rectal carcinoma receiving neoadjuvant chemoradiotherapy (nCRT). Genomic DNA was obtained from formalin-fixed paraffin-embedded (FFPE) specimens of patients with rectal carcinoma who received a complete nCRT course. Gene mutation status was examined in specimens from patients before and after nCRT by using the AmpliSeq platform. Our data revealed that the nonsynonymous p53, APC, KRAS, CDKN2A, and EGFR mutations were observed in 93.1%, 65.5%, 48.6%, and 31% of the patients with rectal adenocarcinoma, respectively. BRAF, FBXW7, PTEN, and SMAD4 mutations were observed in 20.7% of patients with rectal carcinoma. The following 12 gene mutations were observed more frequently in the patients exhibiting a complete response than in those demonstrating a poor response before nCRT: ATM, BRAF, CDKN2A, EGFR, FLT3, GNA11, KDR, KIT, PIK3CA, PTEN, PTPN11, SMAD4, and TP53. In addition, APC, BRAF, FBXW7, KRAS, SMAD4, and TP53 mutations were retained after nCRT. Our results indicate a complex mutational profile in rectal carcinoma, suggesting the involvement of BRAF, SMAD4, and TP53 genetic variants in the outcomes of patients with nCRT.

Protocatechuic Acid, a Gut Bacterial Metabolite of Black Raspberries, Inhibits Adenoma Development and Alters Gut Microbiome Profiles in Apc Min/+ Mice

Administration of black raspberries (BRBs) and their anthocyanin metabolites, including protocatechuic acid (PCA), has been demonstrated to exert chemopreventive effects against colorectal cancer through alteration of innate immune cell trafficking, modulation of metabolic and inflammatory pathways, etc. Previous research has shown that the gut microbiome is important in the effectiveness of chemoprevention of colorectal cancer. This study aimed to assess the potency of PCA versus BRB dietary administration for colorectal cancer prevention using an Apc Min/+ mouse model and determine how bacterial profiles change in response to PCA and BRBs. A control AIN-76A diet supplemented with 5% BRBs, 500 ppm PCA, or 1,000 ppm PCA was administered to Apc Min/+ mice. Changes in incidence, polyp number, and polyp size regarding adenomas of the small intestine and colon were assessed after completion of the diet regimen. There were significant decreases in adenoma development by dietary administration of PCA and BRBs in the small intestine and the 5% BRB-supplemented diet in the colon. Pro-inflammatory bacterial profiles were replaced with anti-inflammatory bacteria in all treatments, with the greatest effects in the 5% BRB and 500 ppm PCA-supplemented diets accompanied by decreased COX-2 and prostaglandin E2 levels in colonic mucosa. We further showed that 500 ppm PCA, but not 1,000 ppm PCA, increased IFN-γ and SMAD4 levels in primary cultured human natural killer cells. These results suggest that both BRBs and a lower dose PCA can benefit colorectal cancer patients by inhibiting the growth and proliferation of adenomas and promoting a more favorable gut microbiome condition.

An Early-Onset Advanced Rectal Cancer Patient With Increased KRAS Gene Copy Number Showed A Primary Resistance to Cetuximab in Combination With Chemotherapy: A Case Report

Mutations in KRAS (codon 12/13), NRAS, BRAF^V600E, and amplification of ERBB2 and MET account for 70–80% of anti-epidermal growth factor receptor (EGFR) monoclonal antibody primary resistance. However, the list of anti-EGFR monoclonal antibody primary resistance biomarkers is still incomplete. Herein, we report a case of wild-type RAS/BRAF metastatic colorectal cancer (CRC) with resistance to anti-EGFR monoclonal antibody and chemotherapy. Initially, mutation detection in postoperative tumor tissue by using amplification-refractory mutation system polymerase chain reaction indicated wild-type RAS/BRAF without point mutations, insertion deletions, or fusion mutations. Therefore, we recommended combined therapy of cetuximab and FOLFIRI after failure of platinum-based adjuvant chemotherapy, but the disease continued to progress. Next generation sequencing analysis of the postoperative tumor tissue revealed that KRAS copy number was increased and detected SMAD4, RNF43, and PREX2 mutations. This is the first case of advanced CRC with increased copy numbers of KRAS resistant to cetuximab and chemotherapy, which results in poor patient survival, and other mutated genes may be associated with the outcomes. Our findings indicate KRAS copy number alterations should also be examined, especially with anti-EGFR monoclonal antibody therapy in CRC, since it may be related with the primary resistance to these drugs.

Role of the BMP6 protein in breast cancer and other types of cancer

The BMP6 protein (Bone Morphogenetic Protein 6) is part of the superfamily of transforming growth factor-beta (TGF-β) ligands, participates in iron homeostasis, inhibits invasion by increasing adhesions and cell-cell type interactions and induces angiogenesis directly on vascular endothelial cells. BMP6 is coded by a tumor suppressor gene whose subexpression is related to the development and cancer progression; during neoplastic processes, methylation is the main mechanism by which gene silencing occurs. This work presents a review on the role of BMP6 protein in breast cancer (BC) and other types of cancer. The studies carried out to date suggest the participation of the BMP6 protein in the epithelial-mesenchymal transition (EMT) phenotype, cell growth and proliferation; however, these processes are affected in a variable way in the different types of cancer, the methylated CpG sites in BMP6 gene promoter, as well as the interaction with other proteins could be the cause of such variation.