Chemoprevention of hereditary colon cancers: time for new strategies

Current management of familial adenomatous polyposis

INTRODUCTION

APC-associated polyposis is a rare hereditary disorder characterized by the development of multiple adenomas in the digestive tract. Individuals with APC-associated polyposis need to be managed by specialized multidisciplinary teams in dedicated centers.

AREAS COVERED

The study aimed to review the literature on Familial adenomatous polyposis (FAP) to provide an update on diagnostic and surgical management while focusing on strategies to minimize the risk of desmoid-type fibromatosis, cancer in anorectal remnant, and postoperative complications. FAP individuals require a comprehensive approach that includes diagnosis, surveillance, preventive surgery, and addressing specific extracolonic concerns such as duodenal and desmoid tumors. Management should be personalized considering all factors: genotype, phenotype, and personal needs. Total colectomy and ileo-rectal anastomosis have been shown to yield superior QoL results when compared to Restorative Procto colectomy and ileopouch-anal anastomosis with acceptable oncological risk of developing cancer in the rectal stump if patients rigorously adhere to lifelong endoscopic surveillance. Additionally, a low-inflammatory diet may prevent adenomas and cancer by modulating systemic and tissue inflammatory indices.

EXPERT OPINION

FAP management requires a multidisciplinary and personalized approach. Integrating genetic advances, innovative surveillance techniques, and emerging therapeutic modalities will contribute to improving outcomes and quality of life for FAP individuals.

Mn(II) Optimized Sono/Chemodynamic Effect of Porphyrin-Metal-Organic Framework Nanosheets for MRI-Guided Colon Cancer Therapy and Metastasis Suppression

Sonodynamic therapy (SDT) offers a remarkable non-invasive ultrasound (US) treatment by activating sonosensitizer and generating reactive oxygen species (ROS) to inhibit tumor growth. The development of multifunctional, biocompatible, and highly effective sonosensitizers remains a current priority for SDT. Herein, the first report that Mn(II) ions chelated Gd-TCPP (GMT) nanosheets (NSs) are synthesized via a simple reflux method and encapsulated with pluronic F-127 to form novel sonosensitizers (GMTF). The GMTF NSs produce a high yield of ROS under US irradiation due to the decreased highest occupied molecular orbital-lowest unoccupied molecular orbital gap energy (2.7-1.28 eV). Moreover, Mn(II) ions endow GMTF with a fascinating Fenton-like activity to produce hydroxyl radicals in support of chemodynamic therapy (CDT). It is also effectively used in magnetic resonance imaging (MRI) with high relaxation rate (r 1: 4.401 mM-1 s-1) to track the accumulation of NSs in tumors. In vivo results indicate that the SDT and CDT in combination with programmed cell death protein 1 antibody (anti-PD-1) show effective metastasis prevention effects, and 70% of the mice in the GMTF + US + anti-PD-1 group survived for 60 days. In conclusion, this study develops a sonosensitizer with promising potential for utilizing both MRI-guided SDT and CDT strategies.

The preimplantation genetic testing for monogenic disorders strategy for blocking the transmission of hereditary cancers through haplotype linkage analysis by karyomapping

PURPOSE

Providing feasible preimplantation genetic testing strategies for monogenic disorders (PGT-M) for prevention and control of genetic cancers.

METHODS

Inclusion of families with a specific pathogenic mutation or a clear family history of genetic cancers. Identification of the distribution of hereditary cancer-related mutations in families through genetic testing. After a series of assisted reproductive measures such as down-regulation, stimulation, egg retrieval, and in vitro fertilization, a biopsy of trophectoderm cells from a blastocyst was performed for single-cell level whole-genome amplification (WGA). Then, the detection of chromosomal aneuploidies was performed by karyomapping. Construction of a haplotype-based linkage analysis to determine whether the embryo carries the mutation. Meanwhile, we performed CNV testing. Finally, embryos can be selected for transfer, and the results will be verified in 18-22 weeks after pregnancy.

RESULTS

Six couples with a total of 7 cycles were included in our study. Except for cycle 1 of case 5 which did not result in a transferable embryo, the remaining 6 cycles produced transferable embryos and had a successful pregnancy. Four couples have had amniotic fluid tests to confirm that the fetus does not carry the mutation, while 1 couple was not tested due to insufficient pregnancy weeks. And the remaining couples had to induce labor due to fetal megacystis during pregnancy.

CONCLUSION

Our strategy has been proven to be feasible. It can effectively prevent transmission of hereditary cancer-related mutations to offspring during the prenatal stage.

LKB1 loss promotes colorectal cancer cell metastasis through regulating TNIK expression and actin cytoskeleton remodeling

Colorectal cancer (CRC) is one of the most common malignant tumors. Approximately 5%-6% of CRC cases are associated with hereditary CRC syndromes, including the Peutz-Jeghers syndrome (PJS). Liver kinase B1 (LKB1), also known as STK11, is the major gene responsible for PJS. LKB1 heterozygotic deficiency is involved in intestinal polyps in mice, while the mechanism of LKB1 in CRC remains elusive. In this study, we generated LKB1 knockout (KO) CRC cell lines by using CRISPR-Cas9. LKB1 KO promoted CRC cell motility in vitro and tumor metastases in vivo. LKB1 attenuated expression of TRAF2 and NCK-interacting protein kinase (TNIK) as accessed by RNA-seq and western blots, and similar suppression was also detected in the tumor tissues of azoxymethane/dextran sodium sulfate-induced intestinal-specific LKB1-KO mice. LKB1 repressed TNIK expression through its kinase activity. Moreover, attenuating TNIK by shRNA inhibited cell migration and invasion of CRC cells. LKB1 loss-induced high metastatic potential of CRC cells was depended on TNIK upregulation. Furthermore, TNIK interacted with ARHGAP29 and further affected actin cytoskeleton remodeling. Taken together, LKB1 deficiency promoted CRC cell metastasis via TNIK upregulation and subsequently mediated cytoskeleton remodeling. These results suggest that LKB1-TNIK axis may play a crucial role in CRC progression.

Updated Perspectives on the Diagnosis and Management of Familial Adenomatous Polyposis

Familial adenomatous polyposis (FAP) is an autosomal dominant cancer predisposition syndrome marked by extensive colorectal polyposis and a high risk of colorectal cancer (CRC). Having access to screening and enrollment programs can improve survival for patients with FAP by enabling them to undergo surgery before the development of colorectal cancer. Provided that there are a variety of surgical options available to treat colorectal polyps in patients with adenomatous polyposis, the appropriate surgical option for each patient should be considered. The gold-standard treatment to reduce this risk is prophylactic colectomy, typically by the age of 40. However, colectomy is linked to morbidity and constitutes an ineffective way at preventing extra-colonic disease manifestations, such as desmoid disease, thyroid malignancy, duodenal polyposis, and cancer. Moreover, extensive studies have been conducted into the use of chemopreventive agents to prevent disease progression and delay the necessity for a colectomy as well as the onset of extracolonic disease. The ideal chemoprevention agent should demonstrate a biologically plausible mechanism of action and provide safety, easy tolerance over an extended period of time and a lasting and clinically meaningful effect. Although many pharmaceutical and non-pharmaceutical products have been tested through the years, there has not yet been a chemoprevention agent that meets these criteria. Thus, it is necessary to develop new FAP agents that target novel pathways, such as the mTOR pathway. The aim of this article is to review the prior literature on FAP in order to concentrate the current and future perspectives of diagnosis and treatment. In conclusion, we will provide an update on the diagnostic and therapeutic options, surgical or pharmaceutical, while focusing on the potential treatment strategies that could further reduce the risk of CRC.

The DNA Damage Response and Inflammation in Cancer

Genomic stability in normal cells is crucial to avoid oncogenesis. Accordingly, multiple components of the DNA damage response (DDR) operate as bona fide tumor suppressor proteins by preserving genomic stability, eliciting the demise of cells with unrepairable DNA lesions, and engaging cell-extrinsic oncosuppression via immunosurveillance. That said, DDR sig-naling can also favor tumor progression and resistance to therapy. Indeed, DDR signaling in cancer cells has been consistently linked to the inhibition of tumor-targeting immune responses. Here, we discuss the complex interactions between the DDR and inflammation in the context of oncogenesis, tumor progression, and response to therapy.

SIGNIFICANCE

Accumulating preclinical and clinical evidence indicates that DDR is intimately connected to the emission of immunomodulatory signals by normal and malignant cells, as part of a cell-extrinsic program to preserve organismal homeostasis. DDR-driven inflammation, however, can have diametrically opposed effects on tumor-targeting immunity. Understanding the links between the DDR and inflammation in normal and malignant cells may unlock novel immunotherapeutic paradigms to treat cancer.

Primary and Secondary Prevention Interventions to Reduce Risk Factors Associated with Colorectal Cancer in High-Risk Groups: a Systematic Literature Review

In the USA, colorectal cancer (CRC) is the 2nd leading cause of cancer-related deaths. Certain groups in the USA are at an increased risk of developing CRC, including those with a genetic risk and family history. The purpose of this project was to synthesize primary and secondary prevention interventions for individuals who are at high risk of CRC due to family history or genetic predisposition. This study systematically reviewed articles from PubMed, Google Scholar, and EBSCO using specific search terms to find relevant articles. Sixteen articles were identified for full-text review, which were categorized as non-drug interventions (n = 7) and drug interventions (n = 9). Non-drug interventions focused primarily on increasing screening in those with a first-degree relative (FDR) with CRC or those with Lynch syndrome (LS). Interventions that increased CRC screening often had a tailored component and were otherwise varied in study designs and intervention type. Drug interventions focused on the use of NSAIDs on patients with familial adenomatous polyposis (FAP). Studies showed very little racial and ethnic diversity. Findings suggest that tailored interventions are particularly effective in increasing CRC screening, and greater diversity of sample is needed with respect to race and ethnicity.

Wnt/β-Catenin Signaling Pathway in the Development and Progression of Colorectal Cancer

The Wnt/β-catenin signaling pathway is a growth control pathway involved in various biological processes as well as the development and progression of cancer. Colorectal cancer (CRC) is one of the most common malignancies in the world. The hyperactivation of Wnt signaling is observed in almost all CRC and plays a crucial role in cancer-related processes such as cancer stem cell (CSC) propagation, angiogenesis, epithelial-mesenchymal transition (EMT), chemoresistance, and metastasis. This review will discuss how the Wnt/β-catenin signaling pathway is involved in the carcinogenesis and progression of CRC and related therapeutic approaches.

Targeting Myc-driven stress addiction in colorectal cancer

MYC is a proto-oncogene that encodes a powerful regulator of transcription and cellular programs essential for normal development, as well as the growth and survival of various types of cancer cells. MYC rearrangement and amplification is a common cause of hematologic malignancies. In epithelial cancers such as colorectal cancer, genetic alterations in MYC are rare. Activation of Wnt, ERK/MAPK, and PI3K/mTOR pathways dramatically increases Myc levels through enhanced transcription, translation, and protein stability. Elevated Myc promotes stress adaptation, metabolic reprogramming, and immune evasion to drive cancer development and therapeutic resistance through broad changes in transcriptional and translational landscapes. Despite intense interest and effort, Myc remains a difficult drug target. Deregulation of Myc and its targets has profound effects that vary depending on the type of cancer and the context. Here, we summarize recent advances in the mechanistic understanding of Myc-driven oncogenesis centered around mRNA translation and proteostress. Promising strategies and agents under development to target Myc are also discussed with a focus on colorectal cancer.

Microbiota-derived tryptophan catabolites mediate the chemopreventive effects of statins on colorectal cancer

Epidemiological studies have indicated an association between statin use and reduced incidence of colorectal cancer (CRC), and work in preclinical models has demonstrated a potential chemopreventive effect. Statins are also associated with reduced dysbiosis in the gut microbiome, yet the role of the gut microbiome in the protective effect of statins in CRC is unclear. Here we validated the chemopreventive role of statins by retrospectively analysing a cohort of patients who underwent colonoscopies. This was confirmed in preclinical models and patient cohorts, and we found that reduced tumour burden was partly due to statin modulation of the gut microbiota. Specifically, the gut commensal Lactobacillus reuteri was increased as a result of increased microbial tryptophan availability in the gut after atorvastatin treatment. Our in vivo studies further revealed that L. reuteri administration suppressed colorectal tumorigenesis via the tryptophan catabolite, indole-3-lactic acid (ILA). ILA exerted anti-tumorigenic effects by downregulating the IL-17 signalling pathway. This microbial metabolite inhibited T helper 17 cell differentiation by targeting the nuclear receptor, RAR-related orphan receptor γt (RORγt). Together, our study provides insights into an anti-cancer mechanism driven by statin use and suggests that interventions with L. reuteri or ILA could complement chemoprevention strategies for CRC.

Lynch Syndrome: From Carcinogenesis to Prevention Interventions

Simple Summary

Promoting proper preventive interventions to reduce morbidity and mortality is one of the most important challenges pertaining to inherited conditions. Lynch syndrome (LS) is an inherited disorder that predisposes to several kinds of tumor and is responsible for a relevant proportion of human colorectal and endometrial cancers. Recent knowledge has allowed for a better understanding of the genetic cause, pathogenesis, underlying immunological mechanisms, epidemiological distribution, and prevalence of this disease. This opens up unpredictable perspectives of translating such knowledge into validated programs for prevention and surveillance, in order to reduce the health impact of this disease through medical interventions before cancer development. In our review, we summarize the updated guidelines of the screening, surveillance, and risk-reducing strategies for LS patients. Moreover, we present novel opportunities in the treatment and prevention of LS patients through harnessing the immune system using immunocheckpoint inhibitors and vaccines.

Abstract

Lynch syndrome (LS) is the most common inherited disorder responsible for an increased risk of developing cancers at different sites, most frequently in the gastrointestinal and genitourinary tracts, caused by a germline pathogenic variant affecting the DNA mismatch repair system. Surveillance and risk-reducing procedures are currently available and warranted for LS patients, depending on underlying germline mutation, and are focused on relevant targets for early cancer diagnosis or primary prevention. Although pharmacological approaches for preventing LS-associated cancer development were started many years ago, to date, aspirin remains the most studied drug intervention and the only one suggested by the main surveillance guidelines, despite the conflicting findings. Furthermore, we also note that remarkable advances in anticancer drug discovery have given a significant boost to the application of novel immunological strategies such as immunocheckpoint inhibitors and vaccines, not only for cancer treatment, but also in a preventive setting. In this review, we outline the clinical, biologic, genetic, and morphological features of LS as well as the recent three-pathways carcinogenesis model. Furthermore, we provide an update on the dedicated screening, surveillance, and risk-reducing strategies for LS patients and describe emerging opportunities of harnessing the immune system.

The CHAMP-study: the CHemopreventive effect of lithium in familial AdenoMatous Polyposis; study protocol of a phase II trial

BACKGROUND

Familial adenomatous polyposis (FAP) is a rare autosomal dominant disease characterized by germline mutations in the Adenomatous Polyposis Coli (APC) gene, resulting in the development of numerous colorectal adenomas. As these patients have a high risk of developing colorectal cancer (CRC), guidelines suggest prophylactic colectomy during early adulthood, however, adenoma development is still observed in the remaining intestinal tract. Therefore, FAP patients would benefit from chemoprevention strategies reducing the development of adenomas. Recent work in mice reveals a chemopreventive effect of lithium on the development of adenomas by inhibiting the expansion of Apc mutated intestinal stem cells (ISCs) within the crypts of normal intestinal mucosa. Here, we aim to investigate the effect of lithium on the spread of APC mutant cells within the human intestinal epithelium.

METHODS

This prospective phase II single arm trial has a duration of 18 months. FAP patients (18-35 years) with a genetically confirmed APC mutation who did not undergo colectomy will be treated with lithium carbonate orally achieving a serum level of 0.2-0.4 mmol/l between month 6 and 12. Colonoscopy with biopsies of normal intestinal mucosa will be performed at baseline and every six months. The primary endpoint is the effect of lithium on the spread of APC mutant cells within intestinal crypts over time by using APC specific marker NOTUM in situ hybridization. Secondary endpoints include change in adenoma burden, patient reported side effects and safety-outcomes. Total sample size is 12 patients and recruitment will take place in the Amsterdam UMC, location AMC in the Netherlands.

DISCUSSION

The outcome of this study will function as a proof-of-concept for the development of novel chemoprevention approaches that interfere with the competition between normal and mutant ISCs.

TRIAL REGISTRATION

ClinicalTrials.gov ( https://clinicaltrials.gov/ ): NCT05402891 (June 1, 2022) and the EU Clinical Trials Register: EuraCT 2022-000240-30 (January 1, 2022).

Management of familial adenomatous polyposis and MUTYH-associated polyposis; new insights

Familial adenomatous polyposis (FAP) and MUTYH-associated polyposis (MAP) are rare inherited polyposis syndromes with a high colorectal cancer (CRC) risk. Therefore, frequent endoscopic surveillance including polypectomy of relevant premalignant lesions from a young age is warranted in patients. In FAP and less often in MAP, prophylactic colectomy is indicated followed by lifelong endoscopic surveillance of the retained rectum after (sub)total colectomy and ileal pouch after proctocolectomy to prevent CRC. No consensus is reached on the right type and timing of colectomy. As patients with FAP and MAP nowadays have an almost normal life-expectancy due to adequate treatment of colorectal polyposis, challenges in the management of FAP and MAP have shifted towards the treatment of duodenal and gastric adenomas as well as desmoid treatment in FAP. Whereas up until recently upper gastrointestinal surveillance was mostly diagnostic and patients were referred for surgery once duodenal or gastric polyposis was advanced, nowadays endoscopic treatment of premalignant lesions is widely performed. Aiming to reduce polyp burden in the colorectum as well as in the upper gastrointestinal tract, several chemopreventive agents are currently being studied.

Metabolomics of Acute vs. Chronic Spinach Intake in an Apc-Mutant Genetic Background: Linoleate and Butanoate Metabolites Targeting HDAC Activity and IFN-γ Signaling

There is growing interest in the crosstalk between the gut microbiome, host metabolomic features, and disease pathogenesis. The current investigation compared long-term (26 week) and acute (3 day) dietary spinach intake in a genetic model of colorectal cancer. Metabolomic analyses in the polyposis in rat colon (Pirc) model and in wild-type animals corroborated key contributions to anticancer outcomes by spinach-derived linoleate bioactives and a butanoate metabolite linked to increased α-diversity of the gut microbiome. Combining linoleate and butanoate metabolites in human colon cancer cells revealed enhanced apoptosis and reduced cell viability, paralleling the apoptosis induction in colon tumors from rats given long-term spinach treatment. Mechanistic studies in cell-based assays and in vivo implicated the linoleate and butanoate metabolites in targeting histone deacetylase (HDAC) activity and the interferon-γ (IFN-γ) signaling axis. Clinical translation of these findings to at-risk patients might provide valuable quality-of-life benefits by delaying surgical interventions and drug therapies with adverse side effects.

Aspirin activates resolution pathways to reprogram T cell and macrophage responses in colitis-associated colorectal cancer

Inflammation is linked with carcinogenesis in many types of cancer including colorectal cancer (CRC). Aspirin is recommended for the prevention of CRC, although the mechanism(s) mediating its immunomodulatory actions remain incompletely understood. Here, we demonstrate that aspirin increased concentrations of the immune-regulatory aspirin-triggered specialized proresolving mediators (AT-SPMs), including AT-lipoxin A4 and AT-resolvin D1, in colonic tissues during inflammation-associated CRC (I-CRC). Aspirin also down-regulated the expression of the checkpoint protein programmed cell death protein-1 in macrophages and CD8+ T cells from the colonic mucosa. Inhibition of AT-SPM biosynthesis or knockout of the AT-SPM receptor Alx/Fpr2 reversed the immunomodulatory actions of aspirin on macrophages and CD8+ T cells and abrogated its protective effects during I-CRC. Furthermore, treatment of mice with AT-SPM recapitulated the immune-directed actions of aspirin during I-CRC. Together, these findings elucidate a central role for AT-SPM in mediating the immune-directed actions of aspirin in regulating I-CRC progression.

Inoscavin A, a pyrone compound isolated from a Sanghuangporus vaninii extract, inhibits colon cancer cell growth and induces cell apoptosis via the hedgehog signaling pathway

BACKGROUND

Sanghuangporus vaninii, a large precious medicinal fungus called Sanghuang in China, has significant antitumor activity. We previously reported that a Sanghuangporus vaninii extract could lead to apoptosis in HT-29 cells through the intrinsic apoptotic pathway. We further found that Inoscavin A exhibited anti-colon cancer activity, but its specific mechanisms have not been fully elucidated.

METHODS

Inoscavin A was obtained from Sanghuangporus vaninii by the classic phytochemical separation technology. The male BALB/c nude mice were injected with HT-29 colon cancer cells as animal model. In order to observe the pathological changes of tumor section, the hematoxylin-eosin(H&E) staining was applied in the histological analysis. Metabolomics was utilized for the investigation of the overall changes of serum metabolites in animal model, and the potential targets of Inoscavin A were analyzed by Ingenuity Pathway Analysis (IPA). We further employed a molecular docking approach to predict the degree of combination of Inoscavin A and Smo. Then we further performed Western blotting and immunofluorescence analysis to investigate the expression of proteins involved in Hh-related pathways in tumor tissues. In addition, the colony formation assay, scratch-wound assay and transwell migration and invasion assay were conducted to evaluate the anti-colon-cancer activity of Inoscavin A. Concurrently, the mitochondrial membrane potential assay and TUNEL apoptosis assay were detected to demonstrate the effect of Inoscavin A on promoting HT-29 cells apoptosis. Western blot experiments verified the anti-tumor effects of Inoscavin A were modulated the protein expression of Shh, Ptch1, Smo and Gli1 in HT-29 cells.

RESULTS

We showed that Inoscavin A, a pyrone compound isolated from the Sanghuangporus vaninii extract, exerted its antitumor activity in an HT-29 colon cancer cell xenograft mouse model. Subsequently, we first time prove that the antitumor effects of Inoscavin A were related to the hedgehog (Hh) signaling pathway. Furthermore, we demonstrated that Smo, the core receptor of the Hh pathway, was critical for the induction of apoptosis of Inoscavin A and that overexpression of this target could significantly rescue cell apoptosis induced by Inoscavin A treatment.

CONCLUSION

Thus, our studies first propose that the natural outgrowth Inoscavin A exerted its anti-cancer effects by inhibiting Smo to suppress the activity of the Hh pathway though inhibiting cell proliferation and promoting apoptosis. These findings further indicate that Inoscavin A will be expected to be a prospective remedical compound for the treatment of colon cancer.

Intestinal microbiota profiles in a genetic model of colon tumorigenesis correlates with colon cancer biomarkers

Faecal (FM) and colon mucosal associated microbiota (MAM) were studied in a model of colorectal cancer (CRC), the Apc-mutated Pirc rats, and in age-paired wt F344 rats. Principal Coordinates Analysis indicated that samples’ distribution was driven by age, with samples of young rats (1 month old; without tumours) separated from older ones (11-month-old; bearing tumours). Diversity analysis showed significant differences between FM and MAM in older Pirc rats, and between MAM of both Pirc and wt rats and the tumour microbiota, enriched in Enterococcus, Escherichia/Shigella, Proteus and Bifidobacteriaceae. In young animals, Pirc FM was enriched in the genus Delftia, while wt FM was enriched in Lactobacillus and Streptococcus. Some CRC biomarkers and faecal short chain fatty acids (SCFAs) were also measured. Colon proliferation and DClK1 expression, a pro-survival mucosal marker, were higher in Pirc than in wt rats, while the mucin MUC2, was lower in Pirc rats. Branched SCFAs were higher in Pirc than in wt animals. By Spearman analysis CRC biomarkers correlated with FM (in both young and old rats) and with MAM (in young rats), suggesting a specific relationship between the gut microbiota profile and these functional mucosal parameters deserving further investigation.

Management of Dietary Habits and Diarrhea in Fap Individuals: A Mediterranean Low-Inflammatory Dietary Intervention

Background: A total colectomy and a frequent life-long endoscopic surveillance are guaranteed to patients with Familial Adenomatous Polyposis (FAP) to reduce their risk of duodenal and rectal stump cancers. However, after surgery, individuals with FAP suffer from an increased number of diarrheal discharges that force them to dietary restrictions. A non-randomized pilot study was conducted to assess whether a three-month low-inflammatory Mediterranean dietary intervention reduces gastro-intestinal markers of inflammation in FAP individuals. The aim of the present work is to evaluate the participant’s adherence to the proposed dietary recommendations and the change in their number of diarrheal discharges. Methods: 26 FAP individuals aged >18 years, who underwent a total colectomy with ileo-rectal anastomosis and were involved in the surveillance program at the Fondazione IRCCS Istituto Nazionale Tumori of Milan, were included in the present analysis. Results: FAP individuals significantly reduced the Not recommended foods (p-value: 0.002) and increased the consumption of the Recommended ones (p-value: 0.075). The adherence to the proposed dietary recommendations was accompanied by a significant decrease in the number of diarrheal discharges (p-value: 0.008). Conclusions: This study suggests that adhering to a low-inflammatory Mediterranean diet has a potential protective effect on the number of diarrheal discharges in FAP individuals.

Gut-Restricted Selective Cyclooxygenase-2 (COX-2) Inhibitors for Chemoprevention of Colorectal Cancer

Selective cyclooxygenase (COX)-2 inhibitors have been extensively studied for colorectal cancer (CRC) chemoprevention. Celecoxib has been reported to reduce the incidence of colorectal adenomas and CRC but is also associated with an increased risk of cardiovascular events. Here, we report a series of gut-restricted, selective COX-2 inhibitors characterized by high colonic exposure and minimized systemic exposure. By establishing acute ex vivo ¹⁸F-FDG uptake attenuation as an efficacy proxy, we identified a subset of analogues that demonstrated statistically significant in vivo dose-dependent inhibition of adenoma progression and survival extension in an APC^min/+ mouse model. However, in vitro-in vivo correlation analysis showed their chemoprotective effects were driven by residual systemic COX-2 inhibition, rationalizing their less than expected efficacies and highlighting the challenges associated with COX-2-mediated CRC disease chemoprevention.

Squalene epoxidase promotes colorectal cancer cell proliferation through accumulating calcitriol and activating CYP24A1-mediated MAPK signaling

Background

Colorectal cancer (CRC) is one of the most malignant tumors with high incidence, yet its molecular mechanism is not fully understood, hindering the development of targeted therapy. Metabolic abnormalities are a hallmark of cancer. Targeting dysregulated metabolic features has become an important direction for modern anticancer therapy. In this study, we aimed to identify a new metabolic enzyme that promotes proliferation of CRC and to examine the related molecular mechanisms.

Methods

We performed RNA sequencing and tissue microarray analyses of human CRC samples to identify new genes involved in CRC. Squalene epoxidase (SQLE) was identified to be highly upregulated in CRC patients. The regulatory function of SQLE in CRC progression and the therapeutic effect of SQLE inhibitors were determined by measuring CRC cell viability, colony and organoid formation, intracellular cholesterol concentration and xenograft tumor growth. The molecular mechanism of SQLE function was explored by combining transcriptome and untargeted metabolomics analysis. Western blotting and real‐time PCR were used to assess MAPK signaling activation by SQLE.

Results

SQLE‐related control of cholesterol biosynthesis was highly upregulated in CRC patients and associated with poor prognosis. SQLE promoted CRC growth in vitro and in vivo. Inhibition of SQLE reduced the levels of calcitriol (active form of vitamin D3) and CYP24A1, followed by an increase in intracellular Ca²⁺ concentration. Subsequently, MAPK signaling was suppressed, resulting in the inhibition of CRC cell growth. Consistently, terbinafine, an SQLE inhibitor, suppressed CRC cell proliferation and organoid and xenograft tumor growth.

Conclusions

Our findings demonstrate that SQLE promotes CRC through the accumulation of calcitriol and stimulation of CYP24A1‐mediated MAPK signaling, highlighting SQLE as a potential therapeutic target for CRC treatment.

Combination of Sulindac and Bexarotene for Prevention of Intestinal Carcinogenesis in Familial Adenomatous Polyposis

Familial adenomatous polyposis (FAP) is a hereditary colorectal cancer syndrome, which results in the development of hundreds of adenomatous polyps carpeting the gastrointestinal tract. NSAIDs have reduced polyp burden in patients with FAP and synthetic rexinoids have demonstrated the ability to modulate cytokine-mediated inflammation and WNT signaling. This study examined the use of the combination of an NSAID (sulindac) and a rexinoid (bexarotene) as a durable approach for reducing FAP colonic polyposis to prevent colorectal cancer development. Whole transcriptomic analysis of colorectal polyps and matched normal mucosa in a cohort of patients with FAP to identify potential targets for prevention in FAP was performed. Drug-dose synergism of sulindac and bexarotene in cell lines and patient-derived organoids was assessed, and the drug combination was tested in two different mouse models. This work explored mRNA as a potential predictive serum biomarker for this combination in FAP. Overall, transcriptomic analysis revealed significant activation of inflammatory and cell proliferation pathways. A synergistic effect of sulindac (300 μmol/L) and bexarotene (40 μmol/L) was observed in FAP colonic organoids with primary targeting of polyp tissue compared with normal mucosa. This combination translated into a significant reduction in polyp development in Apc^Min/+ and Apc^LoxP/+-Cdx2 mice. Finally, the reported data suggest miRNA-21 could serve as a predictive serum biomarker for polyposis burden in patients with FAP. These findings support the clinical development of the combination of sulindac and bexarotene as a treatment modality for patients with FAP. PREVENTION RELEVANCE: This study identified a novel chemopreventive regimen combining sulindac and bexarotene to reduce polyposis in patients with FAP using in silico tools, ex vivo, and in vivo models. This investigation provides the essential groundwork for moving this drug combination forward into a clinical trial.

Oncogenic mutations drive intestinal cancer initiation through paracrine remodeling

Three articles in Nature show that intestinal stem cells with cancer-promoting mutations could shape the surrounding normal tissue in their favor to promote clonal fixation and field expansion, raising the possibility of developing therapeutic strategies that maintain or enhance the health of normal cells to out-compete the mutant cells.

Genetic and biological hallmarks of colorectal cancer

Colorectal cancer has served as a genetic and biological paradigm for the evolution of solid tumors, and these insights have illuminated early detection, risk stratification, prevention, and treatment principles. Employing the hallmarks of cancer framework, we provide a conceptual framework to understand how genetic alterations in colorectal cancer drive cancer cell biology properties and shape the heterotypic interactions across cells in the tumor microenvironment. This review details research advances pertaining to the genetics and biology of colorectal cancer, emerging concepts gleaned from immune and single-cell profiling, and critical advances and remaining knowledge gaps influencing the development of effective therapies for this cancer that remains a major public health burden.

Non-Steroidal Anti-Inflammatory Drugs in Colorectal Cancer Chemoprevention

Simple Summary

There is growing evidence from epidemiologic, preclinical and clinical studies suggesting that non-steroidal anti-inflammatory drugs (NSAIDs) play a beneficial role in colorectal cancer chemoprevention. They reduce the risk of colorectal polyps, mostly by cyclooxygenase-2 inhibition. The aim of our work was to describe the current state of scientific knowledge on the potential added value of the use of NSAIDs (such as aspirin, sulindac, and celecoxib) as chemopreventive agents in patients at risk of colorectal cancer. The study confirmed that there is a link between the long-term use of the NSAIDs and a decrease in the risk of colorectal cancer.

Abstract

Since colorectal cancer is one of the world’s most common cancers, studies on its prevention and early diagnosis are an emerging area of clinical oncology these days. For this study, a review of randomized controlled, double-blind clinical trials of selected NSAIDs (aspirin, sulindac and celecoxib) in chemoprevention of colorectal cancer was conducted. The main molecular anticancer activity of NSAIDs is thought to be a suppression of prostaglandin E₂ synthesis via cyclooxygenase-2 inhibition, which causes a decrease in tumor cell proliferation, angiogenesis, and increases apoptosis. The lower incidence of colorectal cancer in the NSAID patients suggests the long-lasting chemopreventive effect of drugs studied. This new approach to therapy of colorectal cancer may transform the disease from a terminal to a chronic one that can be taken under control.

Molecular Targets in Precision Chemoprevention of Colorectal Cancer: An Update from Pre-Clinical to Clinical Trials

Colorectal cancer (CRC) is one of the leading causes of cancer deaths worldwide. The initiation and progression of CRC is a multi-step process that proceeds via precursor lesions to carcinoma, with each stage characterized by its distinct molecular and tissue microenvironment changes. Precursor lesions of CRC, aberrant crypt foci, and adenoma exhibit drastic changes in genetic, transcriptomic, and proteomic profiles compared to normal tissue. The identification of these changes is essential and provides further validation as an initiator or promoter of CRC and, more so, as lesion-specific druggable molecular targets for the precision chemoprevention of CRC. Mutated/dysregulated signaling (adenomatous polyposis coli, β-catenin, epidermal growth factor receptor, V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS), tumor protein53, Akt, etc.), inflammatory (cyclooxygenase-2, microsomal prostaglandin E synthase-1, inducible nitric oxide synthase, and other pro-inflammatory mediators), and metabolic/growth factor (fatty acid synthase, β-Hydroxy β-methylglutaryl-CoA reductase, and ornithine decarboxylase) related targets are some of the well-characterized molecular targets in the precision chemoprevention of CRC. In this review, we discuss precursor-lesion specific targets of CRC and the current status of pre-clinical studies regarding clinical interventions and combinations for better efficacy and safety toward future precision clinical chemoprevention. In addition, we provide a brief discussion on the usefulness of secondary precision chemopreventive targets for tertiary precision chemoprevention to improve the disease-free and overall survival of advanced stage CRC patients.

A risk-stratified approach to colorectal cancer prevention and diagnosis

Population screening and endoscopic surveillance are used widely to prevent the development of and death from colorectal cancer (CRC). However, CRC remains a major cause of cancer mortality and the increasing burden of endoscopic investigations threatens to overwhelm some health services. This Perspective describes the rationale for and approach to improved risk stratification and decision-making for CRC prevention and diagnosis. Limitations of current approaches will be discussed using the UK as an example of the challenges faced by a particular health-care system, followed by discussion of novel risk biomarker utilization. We explore how risk stratification will be advantageous to current health-care providers and users, enabling more efficient use of limited colonoscopy resources. We discuss risk stratification in the setting of population screening as well as the surveillance of high-risk groups and investigation of symptomatic patients. We also address challenges in the development and validation of risk stratification tools and identify key research priorities.

Cost-effectiveness analysis of genetic diagnostic strategies for Lynch syndrome in Italy

Lynch syndrome (LS) is an autosomal dominant condition caused by pathogenic variants in mismatch repair (MMR) genes that predispose individuals to different malignancies, such as colorectal cancer (CRC) and endometrial cancer. Current guidelines recommended testing for LS in individuals with newly diagnosed CRC to reduce cancer morbidity and mortality in relatives. Economic evaluations in support of such approach, however, are not available in Italy. We developed a decision-analytic model to analyze the cost-effectiveness of LS screening from the perspective of the Italian National Health System. Three testing strategies: the sequencing of all MMR genes without prior tumor analysis (Strategy 1), a sequential IHC and MS-MLPA analysis (Strategy 2), and an age-targeted strategy with a revised Bethesda criteria assessment before IHC and methylation-specific MLPA for patients ≥ than 70 years old (Strategy 3) were analyzed and compared to the “no testing” strategy. Quality Adjusted Life Years (QALYs) in relatives after colonoscopy, aspirin prophylaxis and an intensive gynecological surveillance were estimated through a Markov model. Assuming a CRC incidence rate of 0.09% and a share of patients affected by LS equal to 2.81%, the number of detected pathogenic variants among CRC cases ranges, in a given year, between 910 and 1167 depending on the testing strategy employed. The testing strategies investigated, provided one-time to the entire eligible population (CRC patients), were associated with an overall cost ranging between €1,753,059.93-€10,388,000.00. The incremental cost-effectiveness ratios of the Markov model ranged from €941.24 /QALY to €1,681.93 /QALY, thus supporting that “universal testing” versus “no testing” is cost-effective, but not necessarily in comparison with age-targeted strategies. This is the first economic evaluation on different testing strategies for LS in Italy. The results might support the introduction of cost-effective recommendations for LS screening in Italy.

Immunogenic cell death in colon cancer prevention and therapy

Colorectal cancer (CRC) is a leading cause of cancer-related death worldwide. The colonic mucosa constitutes a critical barrier and a major site of immune regulation. The immune system plays important roles in cancer development and treatment, and immune activation caused by chronic infection or inflammation is well-known to increase cancer risk. During tumor development, neoplastic cells continuously interact with and shape the tumor microenvironment (TME), which becomes progressively immunosuppressive. The clinical success of immune checkpoint blockade therapies is limited to a small set of CRCs with high tumor mutational load and tumor-infiltrating T cells. Induction of immunogenic cell death (ICD), a type of cell death eliciting an immune response, can therefore help break the immunosuppressive TME, engage the innate components, and prime T cell-mediated adaptive immunity for long-term tumor control. In this review, we discuss the current understanding of ICD induced by antineoplastic agents, the influence of driver mutations, and recent developments to harness ICD in colon cancer. Mechanism-guided combinations of ICD-inducing agents with immunotherapy and actionable biomarkers will likely offer more tailored and durable benefits to patients with colon cancer.

Xanthohumol protects against Azoxymethane-induced colorectal cancer in Sprague-Dawley rats

Colorectal cancer (CRC) is a major health problem and third most common deaths in western world. Dietary interventions together with modified dietary style can prevent the CRC in humans. Xanthohumol (XHA), a polyphenol isolated from Humulus lupulus L. contains many beneficial effects. The aim of the study is to analyze the effect of XHA on Azoxymethane (AOM)-induced experimental CRC in rats. Levels of MDA were increased and enzymic antioxidants levels were decreased in AOM-induced rats. However, these levels were reversed upon XHA treatment. Further, the mRNA expressions of iNOS and COX-2 were also downregulated in XHA treated rats compared to AOM-induced rats. Further, we found that administration of XHA suppressed the wnt/β-catenin signaling together with modulation of apoptotic proteins Bax, Bcl-2, and caspase 3. We conclude that XHA can able to quench the free radicals, inhibits cell proliferation and induces apoptosis, thus it can be a chemopreventive/therapeutic agent against CRC.

Repurposing of plant alkaloids for cancer therapy: Pharmacology and toxicology

Drug repurposing (or repositioning) is an emerging concept to use old drugs for new treatment indications. Phytochemicals isolated from medicinal plants have been largely neglected in this context, although their pharmacological activities have been well investigated in the past, and they may have considerable potentials for repositioning. A grand number of plant alkaloids inhibit syngeneic or xenograft tumor growth in vivo. Molecular modes of action in cancer cells include induction of cell cycle arrest, intrinsic and extrinsic apoptosis, autophagy, inhibition of angiogenesis and glycolysis, stress and anti-inflammatory responses, regulation of immune functions, cellular differentiation, and inhibition of invasion and metastasis. Numerous underlying signaling processes are affected by plant alkaloids. Furthermore, plant alkaloids suppress carcinogenesis, indicating chemopreventive properties. Some plant alkaloids reveal toxicities such as hepato-, nephro- or genotoxicity, which disqualifies them for repositioning purposes. Others even protect from hepatotoxicity or cardiotoxicity of xenobiotics and established anticancer drugs. The present survey of the published literature clearly demonstrates that plant alkaloids have the potential for repositioning in cancer therapy. Exploitation of the chemical diversity of natural alkaloids may enrich the candidate pool of compounds for cancer chemotherapy and -prevention. Their further preclinical and clinical development should follow the same stringent rules as for any other synthetic drug as well. Prospective randomized, placebo-controlled clinical phase I and II trials should be initiated to unravel the full potential of plant alkaloids for drug repositioning.

Supplementation with phytoestrogens and insoluble fibers reduces intestinal carcinogenesis and restores ER-β expression in Apc-driven colorectal carcinogenesis

Supplementation with phytoestrogens and insoluble fibers has been reported to reduce duodenal polyps in colectomized familial adenomatous polyposis patients, with a mechanism involving, at least in part, upregulation of estrogen receptor-β subtype, whose expression is lowered during intestinal tumorigenesis. These data suggest a protective effect also in the colon, the main target organ for tumorigenesis in familial adenomatous polyposis and a major cancer type in non-familial (sporadic) cancers. Therefore, we tested whether a similar preparation might reduce tumorigenesis in the colon of Pirc rats (F344/NTac-Apc) mutated in the Apc gene and thus, like familial adenomatous polyposis patients, spontaneously developing multiple tumors in the colon. We first demonstrate that estrogen receptor-β expression in Pirc rat colon is significantly down-regulated compared to age-matched wt rats. Then, Pirc rats aged 1 month were treated for 3 months with Adipol (Adi), a patented preparation containing phytoestrogens and insoluble fibers. Colon tumorigenesis was significantly reduced by Adi treatment (colon tumors/rat were 5.3 ± 0.8 and 2.9 ± 0.3, Mucin Depleted Foci/rat 127 ± 6.6 and 97.1 ± 8.6 in Controls and Adi-treated rats, respectively, means ± SE, P < 0.01). The treatment also normalized colon proliferation pattern along the crypt and significantly increased apoptosis in colon tumors. Estrogen receptor-β expression was increased by Adi treatment, especially in the tumors. These positive effects suggest that Adipol may be exploited as a chemopreventive agent to reduce cancer risk in familial adenomatous polyposis patients and to postpone prophylactic colectomy. Moreover, given the similarities between familial adenomatous polyposis and sporadic colorectal cancer, it might also be used as chemopreventive agent in colorectal cancer patients at risk.

Colorectal cancer

Several decades ago, colorectal cancer was infrequently diagnosed. Nowadays, it is the world's fourth most deadly cancer with almost 900 000 deaths annually. Besides an ageing population and dietary habits of high-income countries, unfavourable risk factors such as obesity, lack of physical exercise, and smoking increase the risk of colorectal cancer. Advancements in pathophysiological understanding have increased the array of treatment options for local and advanced disease leading to individual treatment plans. Treatments include endoscopic and surgical local excision, downstaging preoperative radiotherapy and systemic therapy, extensive surgery for locoregional and metastatic disease, local ablative therapies for metastases, and palliative chemotherapy, targeted therapy, and immunotherapy. Although these new treatment options have doubled overall survival for advanced disease to 3 years, survival is still best for those with non-metastasised disease. As the disease only becomes symptomatic at an advanced stage, worldwide organised screening programmes are being implemented, which aim to increase early detection and reduce morbidity and mortality from colorectal cancer.

Annexin10 promotes extrahepatic cholangiocarcinoma metastasis by facilitating EMT via PLA2G4A/PGE2/STAT3 pathway

Background

Cholangiocarcinoma (CCA), consisting of intrahepatic (IHCCA), perihilar (PHCCA), and distal (DCCA) CCA, is a type of highly aggressive malignancy with a very dismal prognosis. Potential biomarkers and drug targets of CCA are urgently needed. As a new member of the Annexin (ANXA) family, the role of ANXA10 in the progression and prognosis of CCA is unknown.

Methods

Potential PHCCA biomarkers were screened by transcriptome sequencing of 5 pairs of PHCCA and adjacent tissues. The clinical significance of ANXA10 was evaluated by analyzing its correlation with clinicopathological variables, and the prognostic value of ANXA10 was evaluated with univariate and multivariate analyses. The function of ANXA10 in the epithelial-mesenchymal transition (EMT), proliferation, invasion and metastasis was detected with in vitro and in vivo experiments. Moreover, we screened the key molecule in ANXA10-induced CCA progression by mRNA sequencing and evaluated the correlation between PLA2G4A and ANXA10. The effect of PLA2G4A downstream signaling, including Cyclooxygenase 2, Prostaglandin E2(PGE2) and Signal transducer and activator of transcription 3(STAT3), on EMT and metastasis was further detected with in vitro and in vivo experiments.

Findings

ANXA10 expression was upregulated in PHCCA and DCCA but not in IHCCA. High ANXA10 expression was significantly associated with poor tumor differentiation and prognosis. ANXA10 promoted the proliferation, migration and invasion of the PHCCA cells. PLA2G4A expression was regulated by ANXA10 and high PLA2G4A predicted poor prognosis in PHCCA and DCCA. ANXA10 facilitated EMT and promoted metastasis by upregulating PLA2G4A expression, thus increasing PGE2 levels and activating STAT3.

Interpretation

ANXA10 was an independent prognostic biomarker of PHCCA and DCCA but not IHCCA. ANXA10 promoted the progression of PHCCA and facilitated metastasis by promoting the EMT process via the PLA2G4A/PGE2/STAT3 pathway. ANXA10, PLA2G4A and their downstream molecules, such as COX2 and PGE2, may be promising drug targets of PHCCA and DCCA.

Resorting the function of the colorectal cancer gatekeeper adenomatous polyposis coli

As a large number of cancers are caused by nonsense mutations in key genes, read-through of these mutations to restore full-length protein expression is a potential therapeutic strategy. Mutations in the adenomatous polyposis coli (APC) gene initiate the majority of both sporadic and hereditary colorectal cancers (CRC) and around 30% of these mutations are nonsense mutations. Our goal was to test the feasibility and effectiveness of APC nonsense mutation read-through as a potential chemo-preventive therapy in Familial Adenomatous Polyposis (FAP), an inherited CRC syndrome patients. Ten FAP patients harboring APC nonsense mutations were treated with the read-through inducing antibiotic erythromycin for 4 months. Endoscopic assessment of the adenomas was performed at baseline, after 4 and after 12 months. Adenoma burden was documented in terms of adenoma number, maximal polyp size and cumulative polyp size per procedure. Tissue samples were collected and subjected to molecular and genetic analyses. Our results show that in the majority of patients the treatment led to a decrease in cumulative adenoma burden, median reduction in cumulative adenoma size and median reduction in adenoma number. Molecular and genetic analyses of the adenomas revealed that the treatment led to a reduced number of somatic APC mutations, reduced cellular proliferation and restoration of APC tumor-suppressing activity. Together, our findings show that induced read-through of APC nonsense mutations leads to promising clinical results and should be further investigated to establish its therapeutic potential in FAP and sporadic CRCs harboring nonsense APC mutations.

A flavonoid-rich extract from bergamot juice prevents carcinogenesis in a genetic model of colorectal cancer, the Pirc rat (F344/NTac-Apcam1137)

PURPOSE

To determine the potential of a flavonoid-rich extract from bergamot juice (BJe) to prevent colorectal carcinogenesis (CRC) in vivo.

MAIN METHODS

Pirc rats (F344/NTac-Apc^am1137), mutated in Apc, the key gene in CRC, were treated with two different doses of BJe (35 mg/kg or 70 mg/kg body weight, respectively) mixed in the diet for 12 weeks. Then, the entire intestine was surgically removed and dissected for histological, immunohistochemical and molecular analyses.

RESULTS

Rats treated with BJe showed a significant dose-related reduction in the colon preneoplastic lesions mucin-depleted foci (MDF). Colon and small intestinal tumours were also significantly reduced in rats supplemented with 70 mg/kg of BJe. To elucidate the involved mechanisms, markers of inflammation and apoptosis were determined. Compared to controls, colon tumours from BJe 70 mg/kg-supplemented rats showed a significant down-regulation of inflammation-related genes (COX-2, iNOS, IL-1β, IL-6 and IL-10 and Arginase 1). Moreover, in colon tumours from rats fed with 70 mg/kg BJe, apoptosis was significantly higher than in controls. Up-regulation of p53 and down-regulation of survivin and p21 genes was also observed.

CONCLUSIONS

These data indicate a strong chemopreventive activity of BJe that, at least in part, is due to its pro-apoptotic and anti-inflammatory actions. This effect could be exploited as a strategy to prevent CRC in high-risk patients.

Epidemiology of colorectal cancer: incidence, mortality, survival, and risk factors

According to GLOBOCAN 2018 data, colorectal cancer (CRC) is the third most deadly and fourth most commonly diagnosed cancer in the world. Nearly 2 million new cases and about 1 million deaths are expected in 2018. CRC incidence has been steadily rising worldwide, especially in developing countries that are adopting the “western” way of life. Obesity, sedentary lifestyle, red meat consumption, alcohol, and tobacco are considered the driving factors behind the growth of CRC. However, recent advances in early detection screenings and treatment options have reduced CRC mortality in developed nations, even in the face of growing incidence. Genetic testing and better family history documentation can enable those with a hereditary predisposition for the neoplasm to take preventive measures. Meanwhile, the general population can reduce their risk by lowering their red meat, alcohol, and tobacco consumption and raising their consumption of fibre, wholesome foods, and certain vitamins and minerals.

Long-term exposure to extremely low-dose of nicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) induce non-malignant breast epithelial cell transformation through activation of the a9-nicotinic acetylcholine receptor-mediated signaling pathway

Breast cancer (BC) is the most common cancer affecting women worldwide and has been associated with active tobacco smoking. Low levels of nicotine (Nic) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), have been detected in cases of second-hand smoke (SHS). However, the correlation between SHS and BC risk remains controversial. In this study, we investigated whether the physiological SHS achievable dose of Nic and tobacco specific nitrosamine, NNK act together to induce breast carcinogenesis using an in vitro breast cell carcinogenesis model. Immortalized non-tumorigenic breast epithelial cell line, HBL-100 used for a time-course assay, was exposed to very low levels of either Nic or NNK, or both. The time-course assay consisted of 23 cycles of nitrosamines treatment. In each cycle, HBL-100 cells were exposed to 1pM of Nic and/or 100 femtM of NNK for 48 hours. Cells were passaged every 3 days and harvested after 10, 15, and 23 cycles. Our results demonstrated that the tumorigenicity of HBL-100, defined by soft agar colony forming, proliferation, migration and invasion abilities, was enhanced by co-exposure to physiologically SHS achievable doses of Nic and NNK. In addition, α9-nAChR signaling activation, which plays an important role in cellular proliferation and cell survival, was also observed. Importantly, an increase in stemness properties including the prevalence of CD44+/CD24- cells, increase Nanog expression and mammosphere-forming ability were also observed. Our results indicate that chronic and long term exposure to environmental tobacco smoke, may induce breast cell carcinogenesis even at extremely low doses.

Endogenous Anti-Inflammatory Very-Long-Chain Dicarboxylic Acids: Potential Chemopreventive Lipids

In a paradigm shift, cancer research efforts are being dedicated to the discovery of chemopreventive agents. The goal of this approach is to delay or prevent the progression of augmented cell division to established cancer. Research has focused on dietary supplements, drugs, and endogenous lipids that possess anti-inflammatory properties. We undertook a lipidomics analysis of potential endogenous anti-inflammatory/anti-proliferative lipids in human plasma. We performed high-resolution mass spectrometric lipidomics analyses of plasma samples from controls and patients with colorectal, kidney, pancreatic, glioblastoma, and breast cancers. We present evidence that endogenous very-long-chain dicarboxylic acids (VLCDCA) are anti-inflammatory lipids that possess chemopreventative properties. In a family of VLCDCAs, we characterized VLCDCA 28:4, which is decreased in the plasma of patients with colorectal, kidney, and pancreatic cancers. The structure of this biomarker was validated by derivatization strategies, synthesis of the analytical standard, and tandem mass spectrometry. Our data suggest that VLCDCA 28:4 may be a useful blood biomarker for a number of cancers and that resupplying this lipid, via a prodrug for example, may offer a new anti-inflammatory therapeutic strategy for delaying or preventing the progression of cancer and other inflammatory diseases.

A Chinese family affected by lynch syndrome caused by MLH1 mutation

BACKGROUND

Lynch syndrome (LS) is caused by mutations in DNA mismatch repair (MMR) genes, which accounts for 3-5% of colorectal cancer. The risks of several types of cancer are greatly increased among individuals with LS. In this study, 4 members of a Chinese family with a MLH1 pathogenic variant, resulting in colonic carcinoma, was reported.

CASE PRESENTATION

A 52-year-old colon cancer female was brought to us with a family history of colon cancer. Genetic counseling traced 4 members in her family with colon cancer (mother and 3 siblings including the proband) as well as other cancer types. Next generation sequencing (NGS) with a multiple gene panel including MMR genes showed a germline mutation in MLH1 (c.1852_1854delAAG, p.K618del) in all 3 affected family members and confirmed the diagnosis of Lynch syndrome. In addition, this mutation was also identified in a asymptomatic offspring, who was then recommended to a prophylactic measure against cancer. A personalized health care plan was implemented for monitoring the condition and progression of the affected individuals.

CONCLUSION

Based on public database searching followed by pedigree verification, p.K618del variant in MLH1 is a pathogenic mutation, which supported the diagnosis of LS. This case highlights the importance of diagnosis and management in patients with hereditary cancer syndromes, particularly for asymptomatic family members.

Alternative treatments for prophylaxis of colorectal cancer in familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is a rare, hereditary disease characterized by the presence of 100 or more adenomas distributed throughout the colon and rectum. If untreated, colorectal cancer develops in almost 100% of FAP patients. As prophylactic treatment, proctocolectomy with ileal pouch-anal anastomosis remains the surgical treatment of choice. High rates of postoperative complications, however, have been reported with this procedure, including bowel dysfunction, incontinence, and reduced female fecundity. Some novel strategies for preventing hereditary colon cancers have been reported. This review summarizes alternative treatments, including the laparoscopic approach, chemoprevention, endoscopic management, and subtotal colectomy combined with endoscopic treatment, for prophylaxis of colorectal cancer in FAP patients.

Current and emerging therapies for PNETs in patients with or without MEN1

Pancreatic neuroendocrine tumours (PNETs) might occur as a non-familial isolated endocrinopathy or as part of a complex hereditary syndrome, such as multiple endocrine neoplasia type 1 (MEN1). MEN1 is an autosomal dominant disorder characterized by the combined occurrence of PNETs with tumours of the parathyroids and anterior pituitary. Treatments for primary PNETs include surgery. Treatments for non-resectable PNETs and metastases include biotherapy (for example, somatostatin analogues, inhibitors of receptors and monoclonal antibodies), chemotherapy and radiological therapy. All these treatments are effective for PNETs in patients without MEN1; however, there is a scarcity of clinical trials reporting the efficacy of the same treatments of PNETs in patients with MEN1. Treatment of PNETs in patients with MEN1 is challenging owing to the concomitant development of other tumours, which might have metastasized. In recent years, preclinical studies have identified potential new therapeutic targets for treating MEN1-associated neuroendocrine tumours (including PNETs), and these include epigenetic modification, the β-catenin-wingless (WNT) pathway, Hedgehog signalling, somatostatin receptors and MEN1 gene replacement therapy. This Review discusses these advances.

Oral kanglaite injection (KLTI) attenuates the lung cancer-promoting effect of high-fat diet (HFD)-induced obesity

Obesity is a risk factor for cancer and cancer-related mortality, however, its role in lung cancer progression remains controversial. This study aimed to assess whether high-fat diet (HFD)-induced obesity promotes lung cancer progression and whether the promotion can be decreased by Kanglaite injection (KLTI). In vivo, HFD-induced overweight or obesity increases the lung carcinoma incidence and multiplicity in a urethane-induced lung carcinogenic model and cancer-related mortality in a LLC allograft model by increasing oxidative stress and cellular signaling molecules including JAK, STAT3, Akt, mTOR, NF-κB and cyclin D1. These changes resulted in increases in vascular disruption and the lung water content, thereby promoting lung epithelial proliferation and the epithelial-mesenchymal transition (EMT) during carcinogenesis. Chronic KLTI treatment substantially prevented the weight gain resulting from HFD consumption, thereby reversing the metabolic dysfunction-related physiological changes and reducing susceptibility to lung carcinogenesis. In vitro, KLTI significantly suppressed the proliferation and induced apoptosis and differentiation in 3T3-L1 preadipocyte cells and attenuated endothelial cell permeability in HUVECs. Our study indicates that there is a potential relationship between obesity and lung cancer. This is the first study to show that obesity can directly accelerate carcinogen-induced lung cancer progression and that KLTI can decrease the lung cancer-promoting effect of HFD-induced obesity.

Colorectal cancer prevention: Immune modulation taking the stage

Prevention or early detection is one of the most promising strategies against colorectal cancer (CRC), the second leading cause of cancer death in the US. Recent studies indicate that antitumor immunity plays a key role in CRC prevention. Accumulating evidence suggests that immunosurveillance represents a critical barrier that emerging tumor cells have to overcome in order to sustain the course of tumor development. Virtually all of the agents with cancer preventive activity have been shown to have an immune modulating effect. A number of immunoprevention studies aimed at triggering antitumor immune response against early lesions have been performed, some of which have shown promising results. Furthermore, the recent success of immune checkpoint blockade therapy reinforces the notion that cancers including CRC can be effectively intervened via immune modulation including immune normalization, and has stimulated various immune-based combination prevention studies. This review summarizes recent advances to help better harness the immune system in CRC prevention.

Pomegranate By-Products in Colorectal Cancer Chemoprevention: Effects in Apc-Mutated Pirc Rats and Mechanistic Studies In Vitro and Ex Vivo

SCOPE

To investigate the effect of pomegranate mesocarp, a polyphenol-rich by-product of juice production, in colorectal cancer (CRC) chemoprevention.

METHODS AND RESULTS

A mesocarp decoction (PMD) is administered for 6 weeks in the diet to Pirc rats, mutated in Apc, a key-gene in CRC. Mucin-depleted foci (MDFs), as CRC biomarkers, are reduced in PMD-fed rats compared to controls (MDF/colon: 34 ± 4 versus 47 ± 3, p = 0.02). There is an increase in apoptosis in MDFs from PMD-treated rats compared to controls (2.5 ± 0.2 versus 1.6 ± 0.2, p < 0.01). To elucidate the involved mechanisms, two colon-relevant metabolites of the polyphenolic and fiber PMD components, urolithin-A (u-A) and sodium butyrate (SB), are tested alone or in combination in vitro (colon cancer cells), and ex vivo in adenoma (AD) and normal mucosa (NM) from Pirc rats. u-A 25 μm plus SB 2.5 mm (USB) causes a significant reduction in COX-2 protein expression compared to untreated controls (about -70% in cancer cell cultures, AD, and NM), and a strong increase in C-CASP-3 expression in cells (about ten times), in AD and NM (+74 and +69%).

CONCLUSION

These data indicate a chemopreventive activity of PMD due, at least in part, to pro-apoptotic and anti-inflammatory action of its metabolites that could be exploited in high-risk patients.

A Systematic Review on the Existing Screening Pathways for Lynch Syndrome Identification

Background

Lynch syndrome (LS) is the most common hereditary colon cancer syndrome, accounting for 3–5% of colorectal cancer (CRC) cases, and it is associated with the development of other cancers. Early detection of individuals with LS is relevant, since they can take advantage of life-saving intensive care surveillance. The debate regarding the best screening policy, however, is far from being concluded. This prompted us to conduct a systematic review of the existing screening pathways for LS.

Methods

We performed a systematic search of MEDLINE, ISI Web of Science, and SCOPUS online databases for the existing screening pathways for LS. The eligibility criteria for inclusion in this review required that the studies evaluated a structured and permanent screening pathway for the identification of LS carriers. The effectiveness of the pathways was analyzed in terms of LS detection rate.

Results

We identified five eligible studies. All the LS screening pathways started from CRC cases, of which three followed a universal screening approach. Concerning the laboratory procedures, the pathways used immunohistochemistry and/or microsatellite instability testing. If the responses of the tests indicated a risk for LS, the genetic counseling, performed by a geneticist or a genetic counselor, was mandatory to undergo DNA genetic testing. The overall LS detection rate ranged from 0 to 5.2%.

Conclusion

This systematic review reported different existing pathways for the identification of LS patients. Although current clinical guidelines suggest to test all the CRC cases to identify LS cases, the actual implementation of pathways for LS identification has not been realized. Large-scale screening programs for LS have the potential to reduce morbidity and mortality for CRC, but coordinated efforts in educating all key stakeholders and addressing public needs are still required.

Barriers and Facilitating Factors for Implementation of Genetic Services: A Public Health Perspective

More than 15 years after the publication of the sequence of the human genome, the resulting changes in health care have been modest. At the same time, some promising examples in genetic services become visible, which contribute to the prevention of chronic disease such as cancer. These are discussed to identify barriers and facilitating factors for the implementation of genetic services. Examples from oncogenetics illustrate a high risk of serious disease where prevention is possible, especially in relatives. Some 5% of breast cancers and colorectal cancers are attributable to an inherited predisposition. These cancers occur at a relatively young age. DNA testing of relatives of affected patients may facilitate primary and secondary prevention. Training of non-genetic health care workers and health technology assessment are needed, as is translational research in terms of bringing genomics to health care practice while monitoring and evaluating. Stratified screening programs could include cascade screening and risk assessment based on family history. New roles and responsibilities will emerge. A clear assessment of the values implied is needed allowing to balance the pros and cons of interventions to further the responsible innovation of genetic services.