Dysregulation and crosstalk of cellular signaling pathways in colon carcinogenesis

Therapeutic potential of stem cells in colorectal cancer management: Current trends and future prospects

Colorectal cancer (CRC) ranks among the leading causes of cancer-related morbidity and mortality worldwide. Despite progress in understanding its molecular intricacies, the management of CRC, especially in advanced stages, remains a significant clinical hurdle. This review delves into the evolving landscape of stem cell-based therapeutic strategies in CRC, with a specific focus on the interplay between cancer stem cells (CSCs) and CRC pathogenesis and treatment resistance. Highlighting the pivotal roles of CSCs in tumor initiation, progression, metastasis, and recurrence, the review comprehensively examines their involvement in CRC, ranging from normal colonic tissue to cancer initiation. The potential of stem cells for medicinal purposes in CRC management is explored, encompassing diverse modalities such as transplantation, differentiation therapy, immunotherapy, and gene/cell-based approaches. Challenges and opportunities associated with these strategies are also evaluated, providing insights into their clinical potential and limitations. The review also appraises preclinical investigations contributing to the understanding of CRC and stem cells. Current clinical trials, patient stratification strategies, and regulatory considerations related to stem cell-based therapies in CRC are scrutinized. Furthermore, the review explores emerging trends and future directions, including developments in stem cell technologies and ethical considerations. It highlights the transformative potential of stem cell-based therapeutic strategies in CRC.

Advances in Targeted and Chemotherapeutic Strategies for Colorectal Cancer: Current Insights and Future Directions

Colorectal cancer (CRC) remains one of the leading causes of cancer-related mortality worldwide, necessitating the continuous evolution of therapeutic approaches. Despite advancements in early detection and localized treatments, metastatic colorectal cancer (mCRC) poses significant challenges due to low survival rates and resistance to conventional therapies. This review highlights the current landscape of CRC treatment, focusing on chemotherapy and targeted therapies. Chemotherapeutic agents, including 5-fluorouracil, irinotecan, and oxaliplatin, have significantly improved survival but face limitations such as systemic toxicity and resistance. Targeted therapies, leveraging mechanisms like VEGF, EGFR, and Hedgehog pathway inhibition, offer promising alternatives, minimizing damage to healthy tissues while enhancing therapeutic precision. Furthermore, future directions in CRC treatment include exploring innovative targets such as Wnt/β-catenin, Notch, and TGF-β pathways, alongside IGF/IGF1R inhibition. These emerging strategies aim to address drug resistance and improve patient outcomes. This review emphasizes the importance of integrating molecular insights into drug development, advocating for a more personalized approach to combat CRC's complexity and heterogeneity.

Chitosan and hyaluronic acid in colorectal cancer therapy: A review on EMT regulation, metastasis, and overcoming drug resistance

Up to 90% of cancer-related fatalities could be attributed to metastasis. Therefore, understanding the mechanisms that facilitate tumor cell metastasis is beneficial for improving patient survival and results. EMT is considered the main process involved in the invasion and spread of CRC. Essential molecular components like Wnt, TGF-β, and PI3K/Akt play a role in controlling EMT in CRC, frequently triggered by various factors such as Snail, Twist, and ZEB1. These factors affect not only the spread of CRC but also determine the reaction to chemotherapy. The influence of non-coding RNAs, especially miRNAs and lncRNAs, on the regulation of EMT is clear in CRC. Exosomes, involved in cell-to-cell communication, can affect the TME and metastasis of CRC. Pharmacological substances and nanoparticles demonstrate promise as efficient modulators of EMT in CRC. Chitosan and HA are two major carbohydrate polymers with considerable potential in inhibiting CRC. Chitosan and HA can be employed to modify nanoparticles to enhance cargo transport for reducing CRC. Additionally, chitosan and HA-modified nanocarriers, which can be utilized as potential approaches in suppressing EMT and reversing drug resistance in CRC, can inhibit EMT and chemoresistance, crucial components in tumorigenesis.

Notch signaling in digestive system cancers: Roles and therapeutic prospects

Digestive system cancers rank among the most prevalent malignant tumors, maintaining persistently high incidence and mortality rates. Notch signaling activity, often aberrant in esophageal, gastric, hepatic, pancreatic, and colorectal cancers, plays a pivotal role in the initiation, progression, and therapy resistance of these malignancies. As a highly conserved pathway, Notch signaling is integral to cell differentiation, survival, proliferation, stem cell renewal, development, and morphogenesis. Its dysregulation has been increasingly linked to various diseases, particularly digestive system cancers. In these malignancies, altered Notch signaling influences multiple biological processes, including cell proliferation, invasion, cell cycle progression, immune evasion, drug resistance, and stemness maintenance. Understanding the mechanisms of Notch signaling in digestive system cancers is essential for the development of novel targeted therapies. Numerous Notch pathway-targeting drugs are currently in preclinical studies, demonstrating promising efficacy both as monotherapies and in combination with conventional anti-cancer treatments. This review summarizes recent high-quality findings on the involvement of Notch signaling in digestive system cancers, focusing on the expression changes and pathological mechanisms of its dysregulated components. Special emphasis is placed on the potential of translating Notch-targeted approaches into therapeutic strategies, which hold promise for overcoming the limitations of existing treatments and improving the poor prognosis associated with these cancers.

TRIM25, TRIM28 and TRIM59 and Their Protein Partners in Cancer Signaling Crosstalk: Potential Novel Therapeutic Targets for Cancer

Aberrant expression of TRIM proteins has been correlated with poor prognosis and metastasis in many cancers, with many TRIM proteins acting as key oncogenic factors. TRIM proteins are actively involved in many cancer signaling pathways, such as p53, Akt, NF-κB, MAPK, TGFβ, JAK/STAT, AMPK and Wnt/β-catenin. Therefore, this review attempts to summarize how three of the most studied TRIMs in recent years (i.e., TRIM25, TRIM28 and TRIM59) are involved directly and indirectly in the crosstalk between the signaling pathways. A brief overview of the key signaling pathways involved and their general cross talking is discussed. In addition, the direct interacting protein partners of these TRIM proteins are also highlighted in this review to give a picture of the potential protein-protein interaction that can be targeted for future discovery and for the development of novel therapeutics against cancer. This includes some examples of protein partners which have been proposed to be master switches to various cancer signaling pathways.

Forkhead box M1 mediates metabolic reprogramming in human colorectal cancer cells

Metabolic reprogramming is recognized as a hallmark of cancer, enabling cancer cells to acquire essential biomolecules for cell growth, often characterized by upregulated glycolysis and/or fatty acid synthesis-related genes. The transcription factor forkhead box M1 (FOXM1) has been implicated in various cancers, contributing significantly to their development, including colorectal cancer (CRC), a major global health concern. Despite FOXM1's established role in cancer, its specific involvement in the Warburg effect and fatty acid biosynthesis in CRC remains unclear. We analyzed The Cancer Genome Atlas (TCGA) Colonic Adenocarcinoma and Rectal Adenocarcinoma (COADREAD) datasets to derive the correlation of the expression levels between FOXM1 and multiple genes and the survival prognosis based on FOXM1 expression. Using two human CRC cell lines, HT29 and HCT116, we conducted RNAi or plasmid transfection procedures, followed by a series of assays, including RNA extraction, quantitative real-time polymerase chain reaction, Western blot analysis, cell metabolic assay, glucose uptake assay, Oil Red O staining, cell viability assay, and immunofluorescence analysis. Higher expression levels of FOXM1 correlated with a poorer survival prognosis, and the expression of FOXM1 was positively correlated with glycolysis-related genes SLC2A1 and LDHA, de novo lipogenesis-related genes ACACA and FASN, and MYC. FOXM1 appeared to modulate AKT/mammalian target of rapamycin (mTOR) signaling, the expression of c-Myc, proteins related to glycolysis and fatty acid biosynthesis, and glucose uptake, as well as extracellular acidification rate in HT29 and HCT116 cells. In summary, FOXM1 plays a regulatory role in glycolysis, fatty acid biosynthesis, and cellular energy consumption, thereby influencing CRC cell growth and patient prognosis.NEW & NOTEWORTHY Transcription factor forkhead box M1 (FOXM1) regulates glycolysis, fatty acid biosynthesis, and cellular energy consumption, which, together, controls cell growth and patient prognosis in colorectal cancer (CRC).

Notch Signaling Suppression by Golden Phytochemicals: Potential for Cancer Therapy

Cancer is one of the main causes of mortality worldwide. Cancer cells are characterized by unregulated cellular processes, including proliferation, progression, and angiogenesis. The occurrence of these processes is due to the dysregulation of various signaling pathways such as NF-κB (nuclear factor-κB), Wnt/beta-catenin, Notch signaling and MAPK (mitogen-activated protein kinases). Notch signaling pathways cause the progression of various types of malignant tumors. Among the phytochemicals for cancer therapy, several have attracted great interest, including curcumin, genistein, quercetin, silibinin, resveratrol, cucurbitacin and glycyrrhizin. Given the great cellular and molecular heterogeneity within tumors and the high toxicity and side effects of synthetic chemotherapeutics, natural products with pleiotropic effects that simultaneously target numerous signaling pathways appear to be ideal substitutes for cancer therapy. With this in mind, we take a look at the current status, impact and potential of known compounds as golden phytochemicals on key signaling pathways in tumors, focusing on the Notch pathway. This review may be useful for discovering new molecular targets for safe and efficient cancer therapy with natural chemotherapeutics.

Emerging trends in gastrointestinal cancers: Targeting developmental pathways in carcinogenesis and tumor progression

Gastrointestinal carcinomas are a group of cancers associated with the digestive system and its accessory organs. The most prevalent cancers related to the gastrointestinal tract are colorectal, gall bladder, gastric, hepatocellular, and esophageal cancers, respectively. Molecular aberrations in different signaling pathways, such as signal transduction systems or developmental pathways are the chief triggering mechanisms in different cancers Though a massive advancement in diagnostic and therapeutic interventions results in improved survival of patients with gastrointestinal cancer; the lower malignancy stages of these carcinomas are comparatively asymptomatic. Various gastrointestinal-related cancers are detected at advanced stages, leading to deplorable prognoses and increased rates of recurrence. Recent molecular studies have elucidated the imperative roles of several signaling pathways, namely Wnt, Hedgehog, and Notch signaling pathways, play in the progression, therapeutic responsiveness, and metastasis of gastrointestinal-related cancers. This book chapter gives an interesting update on recent findings on the involvement of developmental signaling pathways their mechanistic insight in gastrointestinalcancer. Subsequently, evidences supporting the exploration of gastrointestinal cancer related molecular mechanisms have also been discussed for developing novel therapeutic strategies against these debilitating carcinomas.

Trinity of inflammation, innate immune cells and cross-talk of signalling pathways in tumour microenvironment

Unresolved inflammation is a pathological consequence of persistent inflammatory stimulus and perturbation in regulatory mechanisms. It increases the risk of tumour development and orchestrates all stages of tumorigenesis in selected organs. In certain cancers, inflammatory processes create the appropriate conditions for neoplastic transformation. While in other types, oncogenic changes pave the way for an inflammatory microenvironment that leads to tumour development. Of interest, hallmarks of tumour-promoting and cancer-associated inflammation are striking similar, sharing a complex network of stromal (fibroblasts and vascular cells) and inflammatory immune cells that collectively form the tumour microenvironment (TME). The cross-talks of signalling pathways initially developed to support homeostasis, change their role, and promote atypical proliferation, survival, angiogenesis, and subversion of adaptive immunity in TME. These transcriptional and regulatory pathways invariably contribute to cancer-promoting inflammation in chronic inflammatory disorders and foster "smouldering" inflammation in the microenvironment of various tumour types. Besides identifying common target sites of numerous cancer types, signalling programs and their cross-talks governing immune cells' plasticity and functional diversity can be used to develop new fate-mapping and lineage-tracing mechanisms. Here, we review the vital molecular mechanisms and pathways that establish the connection between inflammation and tumour development, progression, and metastasis. We also discussed the cross-talks between signalling pathways and devised strategies focusing on these interaction mechanisms to harness synthetic lethal drug combinations for targeted cancer therapy.

Novel insights into biomarkers of progression in Desmoid tumor

Desmoid tumor (DT) is a rare neoplasm characterized by the proliferation of myofibroblastic cells that infiltrates and invades adjacent tissues. Due to its locally aggressive and recurrent nature, DT often causes local symptoms and can be challenging to manage clinically. Therefore, identifying biomarkers that can predict the progression of DT and guide treatment decisions is critical. This review summarizes several biomarkers that have been implicated in active surveillance (AS) and the prediction of postoperative recurrence and attempts to elucidate their underlying mechanisms. Some of these novel markers could provide prognostic value for clinicians, and ultimately help facilitate optimal and accurate therapeutic decisions for DT.

Revisiting the therapeutic potential of gingerols against different pharmacological activities

The rhizomes of ginger have been in use in many forms of traditional and alternative medicines. Besides being employed as condiment and flavoring agent, it is used in the treatment of nausea, osteoarthritis, muscle pain, menstrual pain, chronic indigestion, Alzheimer's disease, and cancer. Ginger rhizome contains volatile oils, phenolic compounds and resins, and characterization studies showed that [6]-gingerol, [6]-shogaol, and [6]-paradol are reported to be the pharmacologically active components. Gingerol is a major chemical constituent found as volatile oil in the rhizomes of ginger. It has several medicinal benefits and used for the treatment of rheumatoid arthritis, nausea, cancer, and diabetes. Many studies have been carried out in various parts of the world to isolate and standardize gingerol for their use as a complementary medicine. The present review summarizes wide range of research studies on gingerol and its pharmacological roles in various metabolic diseases.

Inhibition of GSK3β Promotes Proliferation and Suppresses Apoptosis of Porcine Muscle Satellite Cells

As the global population increases, interest in cultured meat (a new research field) is gradually increasing. The main raw material for the production of cultured meat is muscle stem cells called satellite cells isolated from livestock. However, how to mass proliferate and maintain satellite cells in vitro without genetic manipulation remains unclear. In the present study, we isolated and purified porcine muscle satellite cells (PMSCs) from the femur of a 1-day-old piglet and cultured PMSCs by treating them with an inhibitor (XAV939, Tankyrase (TNKS) inhibitor) or an activator (CHIR99021, glycogen synthase kinase 3 beta (GSK3β) inhibitor) of Wnt signaling. The CHIR group treated with 3 μM CHIR99021 showed a significantly increased proliferation rate of PMSCs compared to the SC group (control), whereas the XAV group treated with 1 μM XAV939 showed a significantly decreased proliferation rate of PMSCs. CHIR99021 also inhibited the differentiation of PMSCs by reducing the expression of MyoD while maintaining the expression of Pax7 and suppressed apoptosis by regulating the expression of apoptosis-related proteins and genes. RNA sequencing was performed to obtain gene expression profiles following inhibition or activation of the Wnt signaling pathway and various signaling mechanisms related to the maintenance of satellite cells were identified. Our results suggest that inhibition of GSK3β could dramatically improve the maintenance and mass proliferation ability of PMSCs in vitro by regulating the expression of myogenic markers and the cell cycle.

Inhibition and potential treatment of colorectal cancer by natural compounds via various signaling pathways

Colorectal cancer (CRC) is a common type of malignant digestive tract tumor with a high incidence rate worldwide. Currently, the clinical treatment of CRC predominantly include surgical resection, postoperative chemotherapy, and radiotherapy. However, these treatments contain severe limitations such as drug side effects, the risk of recurrence and drug resistance. Some natural compounds found in plants, fungi, marine animals, and bacteria have been shown to inhibit the occurrence and development of CRC. Although the explicit molecular mechanisms underlying the therapeutic effects of these compounds on CRC are not clear, classical signaling transduction pathways such as NF-kB and Wnt/β-catenin are extensively regulated. In this review, we have summarized the specific mechanisms regulating the inhibition and development of CRC by various types of natural compounds through nine signaling pathways, and explored the potential therapeutic values of these natural compounds in the clinical treatment of CRC.

Apoptosis evasion via long non-coding RNAs in colorectal cancer

Long non-coding RNA (LncRNA) is a novel and diverse class of regulatory transcripts that are frequently dysregulated in numerous tumor types. LncRNAs are involved in a complicated molecular network, regulating gene expression, and modulating diverse cellular activities in different cancers including colorectal cancer (CRC). Evidence indicates that lncRNAs can be used as a potential biomarker for the prognosis and diagnosis of CRC as they are aberrantly expressed in CRC cells. The high expression or silencing of lncRNAs is associated with cell proliferation, invasion, metastasis, chemoresistance and apoptosis in CRC. LncRNAs exert both pro-apoptotic and anti-apoptotic functions in CRC. The expression of some oncogene lncRNAs is upregulated which leads to the inhibition of apoptotic pathways, similarly, the tumor suppressor lncRNAs are downregulated in CRC. In this review, we describe the function and mechanisms of lncRNAs to regulate the expression of genes that are involved directly or indirectly in controlling cellular apoptosis in CRC. Furthermore, we also discussed the different apoptotic pathways in normal cells and the mechanisms by which CRC evade apoptosis.

A γ-Secretase Inhibitor Attenuates Cell Cycle Progression and Invasion in Human Oral Squamous Cell Carcinoma: An In Vitro Study

Notch signaling is associated with many human malignancies, including oral squamous cell carcinoma (OSCC). However, the exact function of Notch signaling in OSCC remains unclear. Here, we investigated the effect of Notch signaling inhibition using a γ-secretase inhibitor (DAPT) on OSCC behaviours in vitro. Bioinformatic analysis of public-available gene expression profiles revealed the dysregulation of the Notch signaling pathway in OSCC compared with normal tissues, indicating the role of Notch signaling in OSCC regulation. RNA sequencing analysis of DAPT-treated human OSCC cells revealed the dysregulation of genes related to cell cycle-related pathways. Blocking Notch signaling significantly inhibited cell proliferation. DAPT-induced G0/G1 cell cycle arrest induced cell apoptosis. Furthermore, cell migration and invasion were also reduced in DAPT-treated cells. These findings indicate that Notch signaling activation participates in OSCC regulation by promoting cell growth, cell cycle progression, cell migration, and invasion. These mechanisms could facilitate OSCC progression. These results imply the potential use of Notch signaling inhibitors as a candidate adjuvant treatment in OSCC patients.

NICD3 regulates the expression of MUC5AC and MUC2 by recruiting SMARCA4 and is involved in the differentiation of mucinous colorectal adenocarcinoma

Adenocarcinoma is the most prevalent histological subtype of colorectal cancer (CRC), with mucinous colorectal adenocarcinoma (MCA) being a unique form. Although the mucinous subtype is known to elicit a worse response to chemotherapy and immunotherapy than the nonmucinous subtype, its pathogenesis remains poorly understood. Neurogenic locus notch homolog protein 3 (NOTCH3), a member of the NOTCH subfamilies, is highly expressed in CRC. In the past three decades, many studies have been performed evaluating the biological role of NOTCH3 in CRC. However, the precise activities of NOTCH3 in MCA, as well as the mechanisms involved in its transcriptional control, are yet to be elucidated. Our finding showed that the critical transcriptional regulatory factor transcription activator BRG1 (SMARCA4) directly binds to the intracellular domain of NOTCH3 to control transcriptional regulation. Moreover, RNA‐sequencing results indicated a common targeting effect on the transcriptional activity of mucin‐5AC (MUC5AC) and mucin‐2 (MUC2) in CRC cells by NOTCH3 and SMARCA4. Furthermore, NOTCH3 was found to control the expressions of MUC5AC and MUC2 in a SMARCA4‐dependent manner. MUC5AC and MUC2, which encode two secreted mucins, are located on chromosome 11p15.5, and are linked to the development of MCA. This finding suggests that the interaction between NOTCH3 and SMARCA4 may be involved in MCA differentiation by jointly targeting MUC5AC and MUC2. Patients with MCA are often treated in accordance with CRC guidelines. Determining the relationship between NOTCH3 and SMARCA4 by demonstrating their interactions in the pathophysiology of MCA could provide novel therapeutic targets and help identify potential prognostic markers for MCA.

Chimeric Peptides/Proteins Encoded by circRNA: An Update on Mechanisms and Functions in Human Cancers

The discovery of circular RNAs and exploration of their biological functions are increasingly attracting attention in cell bio-sciences. Owing to their unique characteristics of being highly conserved, having a relatively longer half-life, and involvement in RNA maturation, transportation, epigenetic regulation, and transcription of genes, it has been accepted that circRNAs play critical roles in the variety of cellular processes. One of the critical importance of these circRNAs is the presence of small open reading frames that enable them to encode peptides/proteins. In particular, these encoded peptides/proteins mediate essential cellular activities such as proliferation, invasion, epithelial-mesenchymal transition, and apoptosis and develop an association with the development and progression of cancers by modulating diverse signaling pathways. In addition, these peptides have potential roles as biomarkers for the prognosis of cancer and are being used as drug targets against tumorigenesis. In the present review, we thoroughly discussed the biogenesis of circRNAs and their functional mechanisms along with a special emphasis on the reported chimeric peptides/proteins encoded by circRNAs. Additionally, this review provides a perspective regarding the opportunities and challenges to the potential use of circRNAs in cancer diagnosis and therapeutic targets in clinics.

Prognostic Impact of LGR5, Prox1, and Notch1 Biomarkers in Stage II to III Colon Cancer

The potentiation and activation of Wnt signaling pathways are now assumed to mediate the self-renewal and proliferation of colon cancer stem cells that are responsible for therapeutic resistance, tumor relapse, and metastasis. We aimed to evaluate LGR5, Prox1, and Notch1 immunohistochemical expression in stage II to III colon cancer. Their predictive role of tumor relapse, overall survival, and disease-free survival was statistically analyzed. Our results revealed that high LGR5 expression was identified in 56.7% of the patients, LGR5 expression was significantly associated with left-sided tumors (P<0.001). Moreover, its expression was significantly associated with the unfavorable tumor characteristics including high grade, deep invasion (pT), lymph node metastasis, and advanced tumor stage (P<0.001 for each). High Prox1 expression was observed in 65% of the cases, and its expression was significantly associated with tumor grade, lymph node metastasis, and the advanced tumor stage (P=0.004, 0.009, 0.016, respectively). Positive Notch1 expression was identified in 35% of patients, and it was inversely associated with high grade lymph node metastasis, deep invasion (pT), and advanced tumor stage (P<0.001 for each). During the follow-up period, the tumor relapse was significantly associated with high LGR5, high Prox1, and negative Notch1 expression. Shorter overall survival and disease-free survival were significantly associated with high LGR5, high Prox1, and negative Notch1 expression. High LGR5, high Prox1, and negative Notch1 expression are unfavorable prognostic factors in colon cancer. Prox1 is a crucial regulator of Notch-independent LGR5+ stem cells that is mostly responsible for relapse and therapeutic resistance in stage II to III colon cancer.

KIAA1522 is a new biomarker of promoting the tumorigenesis and distant metastasis of colorectal carcinoma

PURPOSE

Our research was absorbed into exploring the expression, clinicopathological value, biological significance and signaling pathway of KIAA1522 in colorectal carcinoma and its distant metastasis.

MATERIALS AND METHODS

The expression of KIAA1522 and survival analysis in colorectal carcinoma (CRC) were assessed using GEPIA databases. Then we evaluated the expression of KIAA1522 immunohistochemically in tissue samples of 57 patients with colorectal carcinoma liver metastasis (CRLM). The correlations between the expression of KIAA1522, clinical significance and prognosis of these 57 patients with CRLM were analyzed. The migration and invasion of KIAA1522 were explored by western blotting, CCK-8, colony formation, flow cytometry, wound healing assays and transwell invasion in vitro and tail vein injection models in vivo. Then, transcriptome sequencing and gene set enrichment analysis was performed to identify the signaling pathways involved, while western blotting analysis and immunohistochemistry (IHC) were used to identify the expression of key genes in Notch signaling.

RESULTS

KIAA1522 was overexpressed in CRLM tissues and colon cancer cell lines, and the expression of KIAA1522 in metastatic sites was positively correlated with that in primary sites. In addition, the overexpression of KIAA1522 is associated with poor clinicopathological features. Survival analysis showed that the overexpression of KIAA1522 predicted a low overall survival rate in patients with CRLM. Functional studies suggested that KIAA1522 promotes the proliferation, invasion and migration of colon carcinoma in vitro. KIAA1522 could promote distant metastasis of CRC in vivo. Moreover, KIAA1522 upregulated the Notch signaling pathway in colorectal cancer cell lines in vitro and lung metastatic nodes in vivo.

CONCLUSION

In conclusion, it is suggested that the upregulation of KIAA1522 might promote the tumorigenicity and metastasis of colorectal carcinoma through Notch signaling pathway. KIAA1522 plays a carcinogenic role in the metastasis of colorectal carcinoma and might serve as a new molecular target for the treatment.

Hsa-miR-6165 downregulates insulin-like growth factor-1 receptor (IGF-1R) expression and enhances apoptosis in SW480 cells

MicroRNAs are small non-coding RNAs that are implicated in various biological processes. Hsa-miR-6165 (miR-6165), located in the p75NTR gene, is known to induce apoptosis in human cell lines, but its mechanism of action is not fully understood yet. Here, we predicted the insulin-like growth factor 1 receptor (IGF-1R) gene as a bona fide target for miR-6165. The overexpression of miR-6165 in SW480 cells resulted in significant downregulation of IGF-1R expression as detected by real time quantitative polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA). Also, it resulted in reduced transcript levels of AKT2, AKT3, PI3KR3, PI3KR5, CCND1, c-MYC and P21 genes detected by RT-qPCR analysis. In addition, a direct interaction between miR-6165 and a 3'UTR sequence of the IGF-1R gene was verified through a dual luciferase assay. Furthermore, miR-6165 and IGF-1R showed opposite patterns of expression during the neural differentiation process of NT2 cells. Annexin V analysis and MTT assay showed that miR-6165 overexpression was followed by increased apoptosis and reduced the viability rate of SW480 cells. Moreover, a lower expression level of miR-6165 was detected in high-grade colorectal tumors compared with low-grade tumors. Taken together, the results of our study suggest a tumor suppressive role of miR-6165 in colorectal cancer, which seems to take place by regulating IGF-1R gene expression.

Emerging trends in colorectal cancer: Dysregulated signaling pathways (Review)

Colorectal cancer (CRC) is the third most frequently detected type of cancer, and the second most common cause of cancer‑related mortality globally. The American Cancer Society predicted that approximately 147,950 individuals would be diagnosed with CRC, out of which 53,200 individuals would succumb to the disease in the USA alone in 2020. CRC‑related mortality ranks third among both males and females in the USA. CRC arises from 3 major pathways: i) The adenoma‑carcinoma sequence; ii) serrated pathway; and iii) the inflammatory pathway. The majority of cases of CRC are sporadic and result from risk factors, such as a sedentary lifestyle, obesity, processed diets, alcohol consumption and smoking. CRC is also a common preventable cancer. With widespread CRC screening, the incidence and mortality from CRC have decreased in developed countries. However, over the past few decades, CRC cases and mortality have been on the rise in young adults (age, <50 years). In addition, CRC cases are increasing in developing countries with a low gross domestic product (GDP) due to lifestyle changes. CRC is an etiologically heterogeneous disease classified by tumor location and alterations in global gene expression. Accumulating genetic and epigenetic perturbations and aberrations over time in tumor suppressor genes, oncogenes and DNA mismatch repair genes could be a precursor to the onset of colorectal cancer. CRC can be divided as sporadic, familial, and inherited depending on the origin of the mutation. Germline mutations in APC and MLH1 have been proven to play an etiological role, resulting in the predisposition of individuals to CRC. Genetic alterations cause the dysregulation of signaling pathways leading to drug resistance, the inhibition of apoptosis and the induction of proliferation, invasion and migration, resulting in CRC development and metastasis. Timely detection and effective precision therapies based on the present knowledge of CRC is essential for successful treatment and patient survival. The present review presents the CRC incidence, risk factors, dysregulated signaling pathways and targeted therapies.

Regulation of Hedgehog Signaling by miRNAs and Nanoformulations: A Possible Therapeutic Solution for Colorectal Cancer

Hedgehog (Hh) signaling aberrations trigger differentiation and proliferation in colorectal cancer (CRC). However, the current approaches which inhibit this vital cellular pathway provoke some side effects. Therefore, it is necessary to look for new therapeutic options. MicroRNAs are small molecules that modulate expression of the target genes and can be utilized as a potential therapeutic option for CRC. On the other hand, nanoformulations have been implemented in the treatment of plethora of diseases. Owing to their excessive bioavailability, limited cytotoxicity and high specificity, nanoparticles may be considered as an alternative drug delivery platform for the Hh signaling mediated CRC. This article reviews the Hh signaling and its involvement in CRC with focus on miRNAs, nanoformulations as potential diagnostic/prognostic and therapeutics for CRC.

BRAF paradox breakers PLX8394, PLX7904 are more effective against BRAFV600Ε CRC cells compared with the BRAF inhibitor PLX4720 and shown by detailed pathway analysis

PLX7904 and PLX8394 are novel BRAFV600E inhibitors-BRAFi that are designed to evade the paradoxical MAPK activation, a trait for the name "paradox breakers"-PB. Current FDA approved inhibitors (Vemurafenib, Dabrafenib, Encorafenib) although improved progression-free survival of mtBRAF melanoma patients suffer from this treatment related side effect. mtBRAF Colorectal Cancer (CRC) is resistant to the approved BRAF inhibitors, although combinatorial treatment co-targeting BRAF and EGFR/MEK is offering a promising prospect. In an effort to explore the potential of the novel BRAF inhibitors-PB to impede CRC cell proliferation, they were tested on RKO, HT29 and Colo-205 cells, bearing the BRAFV600E mutation. This study shows that the BRAF paradox breakers PLX7904 and PLX8394 cause a more prolonged MAPK pathway inhibition and achieve a stronger blockage of proliferation and reduced viability than PLX4720, the sister compound of Vemurafenib. In some treatment conditions, cells can undergo apoptosis. Genomic analysis on the more resistant RKO cells treated with PLX7904, PLX8394 and PLX4720 showed similar gene expression pattern, but the alterations imposed by the PB were more intense. Bioinformatic analysis resulted in a short list of genes representing potential master regulators of the cellular response to BRAF inhibitors' treatments. From our results, it is clear that the BRAF paradox breakers present a notable differential regulation of major pathways, like MAPK signalling, apoptosis, cell cycle, or developmental signalling pathways. Combinatorial treatments of BRAFi with Mcl-1 and Notch modulators show a better effect than mono-treatments. Additional pathways could be further exploited in novel efficient combinatorial treatment protocols with BRAFi.

Garcinone C suppresses colon tumorigenesis through the Gli1-dependent hedgehog signaling pathway

BACKGROUND

Although garcinone C, a natural xanthone derivative identified in the pericarp of Garcinia mangostana, has been demonstrated to exert different health beneficial activities in oxidative stress and β-amyloid aggregation, the role of garcinone C in colon tumorigenesis has not been investigated. In addition, aberrant Hedgehog (Hh) signaling activation is associated with tumorigenesis including colon cancer. Here, we hypothesized that garcinone C can prevent colon tumorigenesis through regulating the Hh signaling pathway.

METHOD

Colony formation assay and flow cytometry were used to evaluate the effect of garcinone C on the proliferation and cell cycle progression of colon cancer cells. Protein expression of cell cycle related markers and Hh/Gli1 signaling mediators were determined. The regulatory effect of orally administered garcinone C on the Hh/Gli1 signaling pathway and colon tumorigenesis was evaluated in an azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced colon cancer animal model.

RESULTS

Garcinone C suppressed the proliferation of colon cancer cells, induced G0/G1 cell cycle arrest, as well as regulated the expression of cell cycle-related markers such as cyclin D1, cyclin E, CDK6, and p21. Garcinone C inhibited the expression of Gli1, a key mediator of Hedgehog signaling, and protein kinase B (AKT) phosphorylation in Smo-independent colon cancer cells. In the AOM/DSS-induced colon tumorigenesis model, garcinone C significantly inhibited tumor development, regulated the expression of cell cycle markers and Gli1, and reduced AKT phosphorylation in colon tumor tissues, which is consistent with our in vitro results.

CONCLUSION

Garcinone C can suppress colon tumorigenesis in vitro and in vivo through Gli1-dependent non-canonical Hedgehog signaling, suggesting that it may serve as a potent chemopreventive agent against colon tumorigenesis.

ASR490, a Small Molecule, Overrides Aberrant Expression of Notch1 in Colorectal Cancer

Notch1 activation triggers significant oncogenic signaling that manifests as enhanced metastatic potential and tumorigenesis in colorectal cancer. Novel small-molecule inhibitors, mainly plant-derived analogs, have low toxicity profiles and higher bioavailability. In this study, we have developed a small molecule, ASR490, by modifying structure of naturally occurring compound Withaferin A. ASR490 showed a growth-inhibitory potential by downregulating Notch1 signaling in HCT116 and SW620 cell lines. Docking studies and thermal shift assays confirmed that ASR490 binds to Notch1, whereas no changes in Notch2 and Notch3 expression were seen in colorectal cancer cells. Notch1 governs epithelial-to-mesenchymal transition signaling and is responsible for metastasis, which was abolished by ASR490 treatment. To further confirm the therapeutic potential of ASR490, we stably overexpressed Notch1 in HCT-116 cells and determined its inhibitory potential in transfected colorectal cancer (Notch1/HCT116) cells. ASR490 effectively prevented cell growth in both the vector (P = 0.005) and Notch1 (P = 0.05) transfectants. The downregulation of Notch1 signaling was evident, which corresponded with downregulation of mesenchymal markers, including N-cadherin and β-catenin and induction of E-cadherin in HCT-116 transfectants. Intraperitoneal administration of a 1% MTD dose of ASR490 (5 mg/kg) effectively suppressed the tumor growth in control (pCMV/HCT116) and Notch1/HCT116 in xenotransplanted mice. In addition, downregulation of Notch1 and survival signaling in ASR-treated tumors confirmed the in vitro results. In conclusion, ASR490 appears to be a potent agent that can inhibit Notch1 signaling in colorectal cancer.

Bioinformatics for The Prognostic Value and Function of Cubilin (CUBN) in Colorectal Cancer

Background

Cubilin (CUBN) gene was reported to be a novel risk variant for colorectal cancer (CRC). Previous studies have shown that germline variants in known cancer driver genes are predictive of patient outcome, but no study has systematically analyzed CRC to identify CUBN that can predict patient outcome and function by using bioinformatics.

Material/Methods

The association in expression, clinicopathological parameters, and survival were analyzed by using Oncomine, UNCLA, and GEPIA, while CUBN alterations and related functional networks were identified using cBioPortal. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathways (KEGG) of CUBN in CRC were explored by using LinkOmics. Gene set enrichment analysis (GSEA) examined target networks of kinases, miRNAs, and transcription factors.

Results

We found that CUBN was overexpressed in CRC. Patients who were in advanced TNM stage tended to express higher CUBN mRNA levels, while those who received radiotherapy tended to express relatively lower CUBN mRNA levels. Higher expression of CUBN was found to be associated with shorter overall survival (OS) and disease-free survival (DFS). Moreover, functional networks analysis suggested that CUBN can regulate mismatch repair, terpenoid backbone biosynthesis, base excision repair, and proteasome via vitamin digestion and absorption pathway to influence CRC occurrence.

Conclusions

These findings suggested that CUBN could serve as a prognostic and therapeutic biomarker of CRC in the future.

Function and mechanism exploration of zinc finger protein 64 in lung adenocarcinoma cell growth and metastasis

This paper aims to discover the effect of Zinc Finger Protein 64 (ZFP64) and Notch pathway on lung adenocarcinoma cell. ZFP64 expression in cancer tissue and overall survival analysis was identified by TCGA-LUAD. ZFP64 expressions in tumor tissue (n = 30) and adjacent tissue (n = 30), and in human nontumorigenic bronchial epithelial cell line BEAS-2B and human lung adenocarcinoma cell lines (H23, H1975, H2228, and H2085) were measured via quantitative real-time polymerase chain reaction (qRT-PCR). H1975 cell viability, cell cycle progression, and migration after transfection or under Notch inhibitor MK-0752 treatment were detected through MTT assay, flow cytometer, and wound healing assay, respectively. Expressions of notch intracellular domain (NICD) and hairy and enhancer of split 1 (Hes-1) in H1975 cell were determined by western blot. Epithelial-mesenchymal transition (EMT)-related proteins (E-Cadherin and Vimentin) expressions were identified through qRT-PCR and western blot. ZFP64 expression in lung adenocarcinoma tissue and lung adenocarcinoma cell lines was higher and related to poor prognosis. After transfection, H1975 cell viability, migration, and expressions of Vimentin, NICD and Hes-1 were upregulated yet cell percentage in G0/G1 phase, E-cadherin expression was downregulated by overexpressed ZFP64. However, Notch inhibitor MK-0752 inhibited the effects of overexpressed ZFP64 on H1975 cell viability, cell cycle, migration, EMT progress, and Notch pathway activation. Overexpressed ZFP64 promoted the development of lung adenocarcinoma cells by activating Notch pathway.

Bacteria pathogens drive host colonic epithelial cell promoter hypermethylation of tumor suppressor genes in colorectal cancer

BACKGROUND

Altered microbiome composition and aberrant promoter hypermethylation of tumor suppressor genes (TSGs) are two important hallmarks of colorectal cancer (CRC). Here we performed concurrent 16S rRNA gene sequencing and methyl-CpG binding domain-based capture sequencing in 33 tissue biopsies (5 normal colonic mucosa tissues, 4 pairs of adenoma and adenoma-adjacent tissues, and 10 pairs of CRC and CRC-adjacent tissues) to identify significant associations between TSG promoter hypermethylation and CRC-associated bacteria, followed by functional validation of the methylation-associated bacteria.

RESULTS

Fusobacterium nucleatum and Hungatella hathewayi were identified as the top two methylation-regulating bacteria. Targeted analysis on bona fide TSGs revealed that H. hathewayi and Streptococcus spp. significantly correlated with CDX2 and MLH1 promoter hypermethylation, respectively. Mechanistic validation with cell-line and animal models revealed that F. nucleatum and H. hathewayi upregulated DNA methyltransferase. H. hathewayi inoculation also promoted colonic epithelial cell proliferation in germ-free and conventional mice.

CONCLUSION

Our integrative analysis revealed previously unknown epigenetic regulation of TSGs in host cells through inducing DNA methyltransferase by F. nucleatum and H. hathewayi, and established the latter as CRC-promoting bacteria. Video abstract.

A Review on Notch Signaling and Colorectal Cancer

Colorectal cancer (CRC) has one of the highest mortality rates despite the advancement of treatment options. Aggressive CRC remains difficult to treat owing to the activation of oncogenic signaling pathways such as the Notch signaling pathway. The role of Notch receptors varies according to the difference in their structures; in particular, aberrant activation of Notch1 has been attributed to the severity of CRC. Notch1 activation in CRC is inhibited by small molecule inhibitors that target γ-secretase, an enzyme responsible for the third and last cleavage step of Notch receptors. γ-Secretase also produces the intracellular domain that finally carries out cellular functions by activating downstream effectors. However, most inhibitors block γ-secretase non-selectively and cause severe toxicity. Plant-source-derived small molecules, monoclonal antibodies, biological molecules (such as SiRNAs), and compounds targeting the Notch1 receptor itself or the downstream molecules such as HES1 are some of the options that are in advanced stages of clinical trials. The Negative Regulatory Region (NRR), which plays a central role in the transduction of Notch1 signaling in the event of ligand-dependent and ligand-independent Notch1 processing is also being targeted specifically by monoclonal antibodies (mAbs) to prevent aberrant Notch1 activation. In this review, we discuss the role of Notch1 in CRC, particularly its metastatic phenotype, and how mutations in Notch1, specifically in its NRR region, contribute to the aberrant activation of Notch1 signaling, which, in turn, contributes to CRC pathogenesis. We also discuss prevailing and emerging therapies that target the Notch1 receptor and the NRR region, and we highlight the potential of these therapies in abrogating Notch signaling and, thus, CRC development and progression.

MAGP2, a Component of Extracellular Matrix, Is Upregulated in Colorectal Cancer and Negatively Modulated by miR-200b-3p

Background:

Colorectal cancer is one of the leading causes of cancer-related death worldwide, but its mechanism has not been clarified clearly. Microfibrial-associated glycoprotein 2 is mainly located in extracellular matrix, and its role in colorectal cancer is obscure.

Methods:

Immunohistochemical staining and quantitative real-time polymerase chain reaction were used to compare the expression level of microfibrial-associated glycoprotein 2 in colorectal cancer tissues and adjacent tissues. Western blot was used to detect the expression of microfibrial-associated glycoprotein 2 in colorectal cancer cell lines and normal colonic epithelium cell line. Kaplan-Meier analysis and χ² test were applied to evaluate the potential of microfibrial-associated glycoprotein 2 to function as cancer biomarker. Lentiviral transduction was used to induce microfibrial-associated glycoprotein 2 overexpression in HCT116 cells and NCM460 cells, followed by detecting cell proliferation, migration, and invasion. Quantitative real-time polymerase chain reaction was used to investigate the changes in downstream genes after microfibrial-associated glycoprotein 2 overexpression. Luciferase assay was conducted to validate whether miR-200b-3p can directly target microfibrial-associated glycoprotein 2.

Results:

We validated that microfibrial-associated glycoprotein 2 was upregulated in colorectal cancer samples and cells. We also demonstrated its upregulation was associated with several clinicopathologic features such as Dukes stage (P = .048), differentiation status (P = .034), and local lymphatic metastasis (P = .036) of patients with colorectal cancer, and its high expression indicated shorter overall survival of the patients. Microfibrial-associated glycoprotein 2 overexpression remarkably promoted cell proliferation and metastasis via regulating the downstream genes of Notch, including hes family bHLH transcription factor 1 (HES1), Slug, Snail, matrix metalloproteinase 2, matrix metalloproteinase 9, and Kruppel-like factor 4. We also identified miR-200b-3p as a posttranscriptional regulator of microfibrial-associated glycoprotein 2, which partly explain the high expression mechanism of microfibrial-associated glycoprotein 2 in cancer tissues. Conclusion: Microfibrial-associated glycoprotein 2, negatively modulated by miR-200b-3p, is an oncogene of colorectal cancer associated with patients’ prognosis. It may function as a potential biomarker and therapeutic target for colorectal cancer.

Epigenetics/epigenomics and prevention by curcumin of early stages of inflammatory-driven colon cancer

Colorectal cancer (CRC) is associated with significant morbidity and mortality in the US and worldwide. CRC is the second most common cancer-related death in both men and women globally. Chronic inflammation has been identified as one of the major risk factors of CRC. It may drive genetic and epigenetic/epigenomic alterations, such as DNA methylation, histone modification, and non-coding RNA regulation. Current prevention modalities for CRC are limited and some treatment regimens such as use the nonsteroidal anti-inflammatory drug aspirin may have severe side effects, namely gastrointestinal ulceration and bleeding. Therefore, there is an urgent need of developing alternative strategies. Recently, increasing evidence suggests that several dietary cancer chemopreventive phytochemicals possess anti-inflammation and antioxidative stress activities, and may prevent cancers including CRC. Curcumin (CUR) is the yellow pigment that is found in the rhizomes of turmeric (Curcuma longa). Many studies have demonstrated that CUR exhibit strong anticancer, antioxidative stress, and anti-inflammatory activities by regulating signaling pathways, such as nuclear factor erythroid-2-related factor 2, nuclear factor-κB, and epigenetics/epigenomics pathways of histones modifications, and DNA methylation. In this review, we will discuss the latest evidence in epigenetics/epigenomics alterations by CUR in CRC and their potential contribution in the prevention of CRC.

Cucurbitacin B and I inhibits colon cancer growth by targeting the Notch signaling pathway

Cancer stem cells (CSCs) have the ability to self-renew and induce drug resistance and recurrence in colorectal cancer (CRC). As current chemotherapy doesn’t eliminate CSCs completely, there is a need to identify novel agents to target them. We investigated the effects of cucurbitacin B (C-B) or I (C-I), a natural compound that exists in edible plants (bitter melons, cucumbers, pumpkins and zucchini), against CRC. C-B or C-I inhibited proliferation, clonogenicity, induced G₂/M cell-cycle arrest and caspase-mediated-apoptosis of CRC cells. C-B or C-I suppressed colonosphere formation and inhibited expression of CD44, DCLK1 and LGR5. These compounds inhibited notch signaling by reducing the expression of Notch 1–4 receptors, their ligands (Jagged 1-2, DLL1,3,4), γ-secretase complex proteins (Presenilin 1, Nicastrin), and downstream target Hes-1. Molecular docking showed that C-B or C-I binds to the ankyrin domain of Notch receptor, which was confirmed using the cellular thermal shift assay. Finally, C-B or C-I inhibited tumor xenograft growth in nude mice and decreased the expression of CSC-markers and notch signaling proteins in tumor tissues. Together, our study suggests that C-B and C-I inhibit colon cancer growth by inhibiting Notch signaling pathway.

Signaling pathways involved in colorectal cancer progression

Colorectal cancer (CRC) is the fourth leading cause of the worldwide cancer mortality. Different molecular mechanisms have been attributed to the development and progress of CRC. In this review, we will focus on the mitogen-activated protein kinase (MAPK) cascades downstream of the epidermal growth factor receptor (EGFR), Notch, PI3K/AKT pathway, transforming growth factor-β (TGF-β), and Wnt signaling pathways. Various mutations in the components of these signaling pathways have been linked to the development of CRC. Accordingly, numerous efforts have been carried out to target the signaling pathways to develop novel therapeutic approaches. Herein, we review the signaling pathways involved in the incidence and progression of CRC, and the strategies for the therapy targeting components of signaling pathways in CRC.

Deubiquitylation and stabilization of Notch1 intracellular domain by ubiquitin-specific protease 8 enhance tumorigenesis in breast cancer

Notch, an essential factor in tissue development and homoeostasis, has been reported to play an oncogenic function in a variety of cancers. Here, we report ubiquitin-specific protease 8 (USP8) as a novel deubiquitylase of Notch1 intracellular domain (NICD). USP8 specifically stabilizes and deubiquitylates NICD through a direct interaction. The inhibition of USP8 downregulated the Notch signalling pathway via NICD destabilization, resulting in the retardation of cellular growth, wound closure, and colony forming ability of breast cancer cell lines. These phenomena were restored by the reconstitution of NICD or USP8, supporting the direct interaction between these two proteins. The expression levels of NICD and USP8 proteins were positively correlated in patients with advanced breast cancer. Taken together, our results suggest that USP8 functions as a positive regulator of Notch signalling, offering a therapeutic target for breast cancer.

A New Linkage between the Tumor Suppressor RKIP and Autophagy: Targeted Therapeutics

The complexities of molecular signaling in cancer cells have been hypothesized to mediate cross-network alterations of oncogenic processes such as uncontrolled cell growth, proliferation, acquisition of epithelial-to-mesenchymal transition (EMT) markers, and resistance to cytotoxic therapies. The two biochemically exclusive processes/proteins examined in the present review are the metastasis suppressor Raf-1 kinase inhibitory protein (RKIP) and the cell-intrinsic system of macroautophagy (hereafter referred to as autophagy). RKIP is poorly expressed in human cancer tissues, and low expression levels are correlated with high incidence of tumor growth, metastasis, poor treatment efficacy, and poor prognoses in cancer patients. By comparison, autophagy is a conserved cytoprotective degradation pathway that has been shown to influence the acquisition of resistance to hypoxia and nutrient depletion as well as the regulation of chemo-immuno-resistance and apoptotic evasion. Evidently, a broad library of cancer-relevant studies exists for RKIP and autophagy, although reports of the interactions between pathways involving RKIP and autophagy have been relatively sparse. To circumvent this limitation, the coordinate regulatory and effector mechanisms were examined for both RKIP and autophagy. Here, we propose three putative pathways that demonstrate the inherent pleiotropism and relevance of RKIP and the microtubule-associated protein 1 light chain 3 (MAP1LC3, LC3) on cell growth, proliferation, senescence, and EMT, among the hallmarks of cancer. Our findings suggest that signaling modules involving p53, signal transducer and activator of transcription 3 (STAT3), nuclear factor-κB (NF-κB), and Snail highlight the novel roles for RKIP in the control of autophagy and vice versa. The suggested potential crosstalk mechanisms are new areas of research in which to further study RKIP and autophagy in cancer models. These should lead to novel prognostic motifs and will provide alternative therapeutic strategies for the treatment of unresponsive aggressive cancer types.

Mutual regulation of JAG2 and PRAF2 promotes migration and invasion of colorectal cancer cells uncoupled from epithelial-mesenchymal transition

Background

Our previous studies revealed that Jagged 2 (JAG2) is involved in the regulation of migration and invasion of colon cancer cells without affecting cell proliferation. This study further explored the specific mechanism by which JAG2 promotes migration and invasion of colorectal cancer cells.

Methods

JAG2 mRNA expression in different clinical stages of colorectal cancer and normal intestinal tissues was detected by quantitative PCR (QPCR). QPCR and Western Blot were used to analyze the differential expression of JAG2 mRNA and protein between normal human colon tissue cells and various colorectal cancer cells. Co-expression status of JAG2 and epithelial–mesenchymal transition (EMT) markers in colon cancer tissues and cells was analyzed. The difference between TGF-β-induced EMT model and the JAG2 overexpression model were compared in promoting migration and invasion of HT29 cells. HT29 cells were treated with EMT pathway inhibitors (LY2157299 and Slug siRNA) to identify a cross-talk between the JAG2 effect and the Notch pathway. Co-expressed genes of JAG2 in colorectal cancer cells were identified using siRNA and transcriptome microarray technology. The mutual regulation of JAG2 and the co-expressed gene PRAF2 and the regulation of the paracrine effect of exosomes were analyzed.

Results

JAG2 was abnormally expressed in colorectal cancer tissues and directly related to clinical stages. Similar to the findings in tissues, the expression of both JAG2 mRNA and protein was significantly increased in the colorectal cancer cell lines compared with that of normal colorectal cell line CCD18-Co. It was shown in our cell model that JAG2 was involved in the regulation of migration and invasion independent of the canonical Notch signaling pathway. More interestingly, JAG2 also promoted the migration and invasion of colon cancer cells in a non-EMT pathway. Further analysis revealed the co-expression of JAG2 with PRAF2 in colorectal cancer cells. JAG2-rich exosomes were released from colorectal cancer cells in a PRAF2-dependent way, while these exosomes regulated the metastasis of colorectal cancer cells in a paracrine manner.

Conclusions

This is the evidence supporting the biological function of JAG2 through non-canonical Notch and non-EMT-dependent pathways and also the first demonstration of the functions of PRAF2 in colorectal cancer cells. These findings also provide theoretical basis for the development of small molecules or biological agents for therapeutic intervention targeting JAG2/PRAF2.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0871-5) contains supplementary material, which is available to authorized users.

Functional link between plasma membrane spatiotemporal dynamics, cancer biology, and dietary membrane-altering agents

The cell plasma membrane serves as a nexus integrating extra- and intracellular components, which together enable many of the fundamental cellular signaling processes that sustain life. In order to perform this key function, plasma membrane components assemble into well-defined domains exhibiting distinct biochemical and biophysical properties that modulate various signaling events. Dysregulation of these highly dynamic membrane domains can promote oncogenic signaling. Recently, it has been demonstrated that select membrane-targeted dietary bioactives (MTDBs) have the ability to remodel plasma membrane domains and subsequently reduce cancer risk. In this review, we focus on the importance of plasma membrane domain structural and signaling functionalities as well as how loss of membrane homeostasis can drive aberrant signaling. Additionally, we discuss the intricacies associated with the investigation of these membrane domain features and their associations with cancer biology. Lastly, we describe the current literature focusing on MTDBs, including mechanisms of chemoprevention and therapeutics in order to establish a functional link between these membrane-altering biomolecules, tuning of plasma membrane hierarchal organization, and their implications in cancer prevention.

Concomitant dysregulation of the estrogen receptor and BRAF/MEK signaling pathways is common in colorectal cancer and predicts a worse prognosis

PURPOSE

Recurrence is a major cause of colorectal cancer (CRC)-related death. As yet, the accurate identification of CRC patients at high risk of recurrence is still a major clinical challenge. Previously, we found that an estrogen receptor (ER) pathway gene signature may predict disease recurrence in CRC patients. The aim of this study is to evaluate the potential application of additional pathway-specific gene signatures in the prediction of CRC recurrence.

METHODS

The activities of 26 cancer-related pathways in CRC were semi-quantified using gene signature-based Bayesian binary regression analysis, and putative associations of the pathways with cancer recurrence risk were assessed using survival analysis.

RESULTS

Among the 26 pathways tested, inactivation of the estrogen receptor (ER) pathway was found to be one of the most common events in CRC. Inactivation of this pathway was found to be frequently accompanied by over-activation of the BRAF/MEK pathway, and these two pathways were found to be associated with opposite effects on several clinicopathological CRC features, including microsatellite instability, subsite location, advanced stage and recurrence. Survival analysis of four independent CRC patient cohorts revealed that while the BRAF/MEK pathway was more strongly associated with recurrence than the ER pathway in mixed-stage CRCs, the ER pathway was a better predictor of recurrence than the BRAF/MEK pathway in stage II CRC. A combined use of these two pathways improved the prediction of CRC recurrence in both mixed stage CRC (n = 1122; overall HR: 2.518, 95% CI: 1.570-4.038, p < 0.001) and stage II CRC (n = 535; overall HR: 1.976, 95% CI: 1.306-2.989, p = 0.001).

CONCLUSIONS

Combined activity of the ER and BRAF/MEK pathways may represent a novel biomarker for CRC prognosis and clinical management.

NOTUM Is Involved in the Progression of Colorectal Cancer

BACKGROUND

There are limitations to current colorectal cancer (CRC)-specific diagnostic methods and therapies. Tumorigenesis proceeds because of interaction between cancer cells and various surrounding cells; discovering new molecular mediators through studies of the CRC secretome is a promising approach for the development of CRC diagnostics and therapies.

MATERIALS AND METHODS

A comparative secretomic analysis was performed using primary and metastatic human isogenic CRC cells. Proliferation was determined by MTT and thymidine incorporation assay, migration was determined by wound-healing assay (ELISA). The level of palmitoleoyl-protein carboxylesterase (NOTUM) in plasma from patients with CRC was determined by enzyme-linked immunosorbent assay.

RESULTS

NOTUM expression was increased in metastatic cells. Proliferation was suppressed by inhibiting expression of NOTUM. Knockdown of NOTUM genes inhibited proliferation as well as migration, with possible involvement of p38 and c-JUN N-terminal kinase in this process. The result was verified in patients with CRC.

CONCLUSION

NOTUM may be a new candidate for diagnostics and therapy of CRC.

POFUT1 promotes colorectal cancer development through the activation of Notch1 signaling

Copy number variations (CNVs) are key drivers of colorectal cancer (CRC). Our previous studies revealed that protein O-fucosyltransferase 1 (POFUT1) overexpression is driven by CNVs during CRC development. The potential role and underlying mechanisms of POFUT1 in CRC were not investigated. In this study, we analyzed the expression of POFUT1 in CRC from cosmic and TCGA databases and confirmed that POFUT1 is highly expressed in CRC. We used well characterized CRC cell lines, including SW620 and HCT116 to establish a model POFUT1 knockdown cell line. Using these cells, we investigated the role of POFUT1 in CRC. Our data revealed that silencing POFUT1 in CRC cells inhibits cell proliferation, decreases cell invasion and migration, arrests cell cycle progression, and stimulates CRC cell apoptosis in vitro. We further demonstrate that POFUT1 silencing dramatically suppresses CRC tumor growth and transplantation in vivo. We additionally reveal new mechanistic insights into the role of POFUT1 during CRC, through demonstrating that POFUT1 silencing inhibits Notch1 signaling. Taken together, our findings demonstrate that POFUT1 is a tumor activating gene during CRC development, which positively regulates CRC tumor progression through activating Notch1.

Effect of dietary components on miRNA and colorectal carcinogenesis

Background

Colorectal cancer (CRC) is one of the most common cancers diagnosed and among the commonest causes of cancer-related mortality globally. Despite the various available treatment options, millions of people still suffer from this illness and most of these treatment options have several limitations. Therefore, a less expensive, non-invasive or a treatment that requires the use of dietary products remains a focal point in this review.

Main body

Aberrant microRNA expression has been revealed to have a functional role in the initiation and progression of CRC. These has shown significant promise in the diagnosis and prognosis of CRC, owing to their unique expression profile associated with cancer types and malignancies. Moreover, microRNA therapeutics show a great promise in preclinical studies, and these encourage further development of their clinical use in CRC patients. Additionally, emerging studies show the chemo-preventive potential of dietary components in microRNA modulation using several CRC models. This review examines the dietary interplay between microRNAs and CRC incidence. Improving the understanding of the interactions between microRNAs and dietary components in the carcinogenesis of CRC will assist the study of CRC progression and finally, in developing personalized approaches for cancer prevention and therapy.

Conclusion

Although miRNA research is still at its infancy, it could serve as a promising predictive biomarkers and therapeutic targets for CRC. Given the ever-expanding number of miRNAs, understanding their functional aspects represents a promising option for further research.

RASAL2 promotes tumor progression through LATS2/YAP1 axis of hippo signaling pathway in colorectal cancer

Background

Patients with colorectal cancer (CRC) have a high incidence of regional and distant metastases. Although metastasis is the main cause of CRC-related death, its molecular mechanisms remain largely unknown.

Methods

Using array-CGH and expression microarray analyses, changes in DNA copy number and mRNA expression levels were investigated in human CRC samples. The mRNA expression level of RASAL2 was validated by qRT-PCR, and the protein expression was evaluated by western blot as well as immunohistochemistry in CRC cell lines and primary tumors. The functional role of RASAL2 in CRC was determined by MTT proliferation assay, monolayer and soft agar colony formation assays, cell cycle analysis, cell invasion and migration and in vivo study through siRNA/shRNA mediated knockdown and overexpression assays. Identification of RASAL2 involved in hippo pathway was achieved by expression microarray screening, double immunofluorescence staining and co-immunoprecipitation assays.

Results

Integrated genomic analysis identified copy number gains and upregulation of RASAL2 in metastatic CRC. RASAL2 encodes a RAS-GTPase-activating protein (RAS-GAP) and showed increased expression in CRC cell lines and clinical specimens. Higher RASAL2 expression was significantly correlated with lymph node involvement and distant metastasis in CRC patients. Moreover, we found that RASAL2 serves as an independent prognostic marker of overall survival in CRC patients. In vitro and in vivo functional studies revealed that RASAL2 promoted tumor progression in both KRAS/NRAS mutant and wild-type CRC cells. Knockdown of RASAL2 promoted YAP1 phosphorylation, cytoplasm retention and ubiquitination, therefore activating the hippo pathway through the LATS2/YAP1 axis.

Conclusions

Our findings demonstrated the roles of RASAL2 in CRC tumorigenesis as well as metastasis, and RASAL2 exerts its oncogenic property through LATS2/YAP1 axis of hippo signaling pathway in CRC.

Electronic supplementary material

The online version of this article (10.1186/s12943-018-0853-6) contains supplementary material, which is available to authorized users.

The Microbiological Memory, an Epigenetic Regulator Governing the Balance Between Good Health and Metabolic Disorders

If the transmission of biological information from one generation to the next is based on DNA, most heritable phenotypic traits such as chronic metabolic diseases, are not linked to genetic variation in DNA sequences. Non-genetic heritability might have several causes including epigenetic, parental effect, adaptive social learning, and influence of the ecological environment. Distinguishing among these causes is crucial to resolve major phenotypic enigmas. Strong evidence indicates that changes in DNA expression through various epigenetic mechanisms can be linked to parent-offspring resemblance in terms of sensitivity to metabolic diseases. Among non-genetic heritable traits, early nutrition could account for a long term deviant programming of genes expression responsible for metabolic diseases in adulthood. Nutrition could shape an inadequate gut microbiota (dysbiosis), triggering epigenetic deregulation of transcription which can be observed in chronic metabolic diseases. We review herein the evidence that dysbiosis might be a major cause of heritable epigenetic patterns found to be associated with metabolic diseases. By taking into account the recent advances on the gut microbiome, we have aggregated together different observations supporting the hypothesis that the gut microbiota could promote the molecular crosstalk between bacteria and surrounding host cells which controls the pathological epigenetic signature. We introduce for the first time the concept of "microbiological memory" as the main regulator of the epigenetic signatures, thereby indicating that different causes of non-genetic heritability can interact in complex pathways to produce inheritance.

Cross talk of chromosome instability, CpG island methylator phenotype and mismatch repair in colorectal cancer

Colorectal cancer is a severe cancer associated with a high prevalence and fatality rate. There are three major mechanisms for colorectal cancer: (1) Chromosome instability (CIN), (2) CpG island methylator phenotype (CIMP) and (3) mismatch repair (MMR), of which CIN is the most common type. However, these subtypes are not exclusive and overlap. To investigate their biological mechanisms and cross talk, the gene expression profiles of 585 colorectal cancer patients with CIN, CIMP and MMR status records were collected. By comparing the CIN+ and CIN-samples, CIMP+ and CIMP-samples, MMR+ and MMR-samples with minimal redundancy maximal relevance (mRMR) and incremental feature selection (IFS) methods, the CIN, CIMP and MMR associated genes were selected. Unfortunately, there was little direct overlap among them. To investigate their indirect interactions, downstream genes of CIN, CIMP and MMR were identified using the random walk with restart (RWR) method and a greater overlap of downstream genes was indicated. The common downstream genes were involved in biosynthetic and metabolic pathways. These findings were consistent with the clinical observation of wide range metabolite aberrations in colorectal cancer. To conclude, the present study gave a gene level explanation of CIN, CIMP and MMR, but also showed the network level cross talk of CIN, CIMP and MMR. The common genes of CIN, CIMP and MMR may be useful for cross-subtype general colorectal cancer drug development.

TGFBR1*6A is a potential modifier of migration and invasion in colorectal cancer cells

Type 1 transforming growth factor β receptor (TGFBR1)*6A, a common hypomorphic variant of TGFBR1, may act as a susceptibility allele in colorectal cancer. However, the contribution of TGFBR1*6A to colorectal cancer development is largely unknown. To test the hypothesis that TGFBR1*6A promotes colorectal cancer invasion and metastasis via Smad-independent transforming growth factor-β (TGF-β) signaling, the effect of TGFBR1*6A on the invasion of colorectal cancer cells was assessed. pCMV5-TGFBR1*6A-HA plasmids were transfected into SW48 and DLD-1 cells by Lipofectamine-mediated DNA transfection. The effect of TGF-β1 on the proliferation of SW48 and DLD-1 cells transfected with TGFBR1*6A was determined by MTT assay. The effects of the TGF-β1 on the invasion of the transfected SW48 and DLD-1 cells were determined using Matrigel-coated plates. Transforming migrating chambers were used to determine the effects of TGF-β1 on the migration of the transfected SW48 and DLD-1 cells. Western blot analysis was used to determine the expression of phosphorylated (p-) extracellular-signal-regulated kinase (ERK), p-P38 and p-SMAD family member 2 in SW48 cells. Using transfected TGFBR1*6A SW48 and DLD-1 cell lines our group demonstrated that, in comparison with TGFBR1*9A, TGFBR1*6A is capable of switching TGF-β1 growth-inhibitory signals into growth-stimulatory signals which significantly increased the invasion of SW48 and DLD-1 cells. Functional assays indicated that TGFBR1*6A weakened Smad-signaling but increased ERK and p38 signaling, which are crucial mediators of cell migration and invasion. From this, it was possible to conclude that TGFBR1*6A enhanced SW48 cell migration and invasion through the mitogen-activated protein kinase pathway and that it may contribute to colorectal cancer progression in a TGF-β1/Smad signaling-independent manner. This suggests that TGFBR1*6A may possess oncogenic properties and that it may affect the migration and invasion of colorectal cancer cells.

TRAP1 protein signature predicts outcome in human metastatic colorectal carcinoma

TRAP1 is a HSP90 molecular chaperone upregulated in colorectal carcinomas and involved in control of intracellular signaling, cell cycle, apoptosis and drug resistance, stemness and bioenergetics through co-traslational regulation of a network of client proteins. Thus, the clinical significance of TRAP1 protein network was analyzed in human colorectal cancers. TRAP1 and/or its client proteins were quantified, by immunoblot analysis, in 60 surgical specimens of colorectal carcinomas at different stages and, by immunohistochemistry, in 9 colorectal adenomatous polyps, 11 in situ carcinomas and 55 metastatic colorectal tumors. TRAP1 is upregulated at the transition between low- and high-grade adenomas, in in situ carcinomas and in about 60% of human colorectal carcinomas, being downregulated only in a small cohort of tumors. The analysis of TCGA database showed that a subgroup of colorectal tumors is characterized by gain/loss of TRAP1 copy number, this correlating with its mRNA and protein expression. Interestingly, TRAP1 is co-expressed with the majority of its client proteins and hierarchical cluster analysis showed that the upregulation of TRAP1 and associated 6-protein signature (i.e., IF2α, eF1A, TBP7, MAD2, CDK1 and βCatenin) identifies a cohort of metastatic colorectal carcinomas with a significantly shorter overall survival (HR 5.4; 95% C.I. 1.1-26.6; p=0.037). Consistently, the prognostic relevance of TRAP1 was confirmed in a cohort of 55 metastatic colorectal tumors. Finally, TRAP1 positive expression and its prognostic value are more evident in left colon cancers. These data suggest that TRAP1 protein network may provide a prognostic signature in human metastatic colorectal carcinomas.