Biology and therapeutic implications of VEGF-A splice isoforms and single-nucleotide polymorphisms in colorectal cancer

Correlation between inflammatory cytokines and the likelihood of developing multiple types of digestive system cancers: A Mendelian randomization study

OBJECTIVE

Inflammatory cytokines have been linked to digestive system cancers, yet their exact causal connection remains uncertain. Consequently, we conducted a Mendelian randomization (MR) analysis to gauge how inflammatory cytokines are linked to the risk of five prevalent digestive system cancers (DSCs).

METHODS

We collected genetic variation data for 41 inflammatory cytokines from genome-wide association studies (GWAS), and the results data for five common diseases from the Finnish database. Our primary analytical approach involved employing the inverse-variance weighted, residual sum (IVW) method, complemented by the MR-Egger method, the weighted median method, simple mode analysis, and weighted mode analysis as supplementary analytical techniques. Furthermore, we conducted multiple sensitivity analyses.

RESULTS

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), macrophage colony-stimulating factor (M-CSF), and interleukin (IL)-18 showed a negative association with the risk of hepatocellular carcinoma. Conversely, TRAIL was inversely linked to the risk of gastric cancer, while IL-16 exhibited a positive correlation with gastric cancer risk. Stem cell factor (SCF) acted as a protective factor against pancreatic cancer. For colorectal cancer, IL-7, IL-9, IL-13, and vascular endothelial growth factor (VEGF) were identified as risk factors. Notably, our results did not indicate a significant correlation between inflammatory cytokines and the risk of esophageal cancer.

CONCLUSION

Our research unveils potential connections between 41 inflammatory cytokines and the risk of five common DSCs through a MR analysis. These associations offer valuable insights that could aid in the development of diagnostic biomarkers and the identification of novel therapeutic targets for DSCs.

Anti-angiogenesis in colorectal cancer therapy

The morbidity of colorectal cancer (CRC) has risen to third place among malignant tumors worldwide. In addition, CRC is a common cancer in China whose incidence increases annually. Angiogenesis plays an important role in the development of tumors because it can bring the nutrients that cancer cells need and take away metabolic waste. Various mechanisms are involved in the formation of neovascularization, and vascular endothelial growth factor is a key mediator. Meanwhile, angiogenesis inhibitors and drug resistance (DR) are challenges to consider when formulating treatment strategies for patients with different conditions. Thus, this review will discuss the molecules, signaling pathways, microenvironment, treatment, and DR of angiogenesis in CRC.

Biological factors driving colorectal cancer metastasis

Approximately 20% of colorectal cancer (CRC) patients present with metastasis at diagnosis. Among Stage I-III CRC patients who undergo surgical resection, 18% typically suffer from distal metastasis within the first three years following initial treatment. The median survival duration after the diagnosis of metastatic CRC (mCRC) is only 9 mo. mCRC is traditionally considered to be an advanced stage malignancy or is thought to be caused by incomplete resection of tumor tissue, allowing cancer cells to spread from primary to distant organs; however, increasing evidence suggests that the mCRC process can begin early in tumor development. CRC patients present with high heterogeneity and diverse cancer phenotypes that are classified on the basis of molecular and morphological alterations. Different genomic and nongenomic events can induce subclone diversity, which leads to cancer and metastasis. Throughout the course of mCRC, metastatic cascades are associated with invasive cancer cell migration through the circulatory system, extravasation, distal seeding, dormancy, and reactivation, with each step requiring specific molecular functions. However, cancer cells presenting neoantigens can be recognized and eliminated by the immune system. In this review, we explain the biological factors that drive CRC metastasis, namely, genomic instability, epigenetic instability, the metastatic cascade, the cancer-immunity cycle, and external lifestyle factors. Despite remarkable progress in CRC research, the role of molecular classification in therapeutic intervention remains unclear. This review shows the driving factors of mCRC which may help in identifying potential candidate biomarkers that can improve the diagnosis and early detection of mCRC cases.

Targeted splicing therapy: new strategies for colorectal cancer

RNA splicing is the process of forming mature mRNA, which is an essential phase necessary for gene expression and controls many aspects of cell proliferation, survival, and differentiation. Abnormal gene-splicing events are closely related to the development of tumors, and the generation of oncogenic isoform in splicing can promote tumor progression. As a main process of tumor-specific splicing variants, alternative splicing (AS) can promote tumor progression by increasing the production of oncogenic splicing isoforms and/or reducing the production of normal splicing isoforms. This is the focus of current research on the regulation of aberrant tumor splicing. So far, AS has been found to be associated with various aspects of tumor biology, including cell proliferation and invasion, resistance to apoptosis, and sensitivity to different chemotherapeutic drugs. This article will review the abnormal splicing events in colorectal cancer (CRC), especially the tumor-associated splicing variants arising from AS, aiming to offer an insight into CRC-targeted splicing therapy.

Targeted Therapies in Colorectal Cancer: Recent Advances in Biomarkers, Landmark Trials, and Future Perspectives

In 2022, approximately 600,000 cancer deaths were expected; more than 50,000 of those deaths would be from colorectal cancer (CRC). The CRC mortality rate in the US has decreased in recent decades, with a 51% drop between 1976 and 2014. This drop is attributed, in part, to the tremendous therapeutic improvements, especially after the 2000s, in addition to increased social awareness regarding risk factors and diagnostic improvement. Five-fluorouracil, irinotecan, capecitabine, and later oxaliplatin were the mainstays of mCRC treatment from the 1960s to 2002. Since then, more than a dozen drugs have been approved for the disease, betting on a new chapter in medicine, precision oncology, which uses patient and tumor characteristics to guide the therapeutic choice. Thus, this review will summarize the current literature on targeted therapies, highlighting the molecular biomarkers involved and their pathways.

Effects of anesthetic depth on perioperative T lymphocyte subsets in patients undergoing laparoscopic colorectal cancer surgery: a prospective, parallel-controlled randomized trial

BACKGROUND

During the perioperative period, the surgical stress response induced by surgical trauma tends to cause a decrease in peripheral lymphocytes. Anesthetics could reduce the stress response during surgery and prevent sympathetic nerve overexcitation. The goal of this study was to investigate how BIS-guided anesthetic depth affected peripheral T lymphocytes in patients undergoing laparoscopic colorectal cancer surgery.

METHODS

A total of 60 patients having elective laparoscopic colorectal cancer surgery were randomly assigned and analyzed (n = 30 for deep general anesthesia, BIS 35, n = 30 for light general anesthesia, BIS 55). Blood samples were collected immediately before anesthesia induction and immediately after operation, 24 h and 5 days postoperatively. The CD4+/CD8 + ratio, T lymphocyte subsets (including CD3 + T cells, CD4 + T cells, and CD8 + T cells), and natural killer (NK) cells were analyzed by flow cytometry. Serum interleukin-6 (IL-6), interferon -ɣ (IFN-ɣ), and vascular endothelial growth factor-α (VEGF-α) were also measured.

RESULTS

The CD4+/CD8 + ratio decreased 24 h after surgery in two groups, but the reduction did not differ between the two groups (P > 0.05). The concentration of IL-6 and the numerical rating scale (NRS) score in the BIS 55 group were significantly higher than that in the BIS 35 group 24 h after surgery (P = 0.001). There were no intergroup differences in CD3 + T cells, CD4 + T cells, CD8 + T cells, NK cells, VEGF-α, or the IFN-ɣ. Statistical analyses showed no differences between the two groups in the incidence of fever and surgical site infection during hospitalization.

CONCLUSIONS

Despite the fact that patients in deep general anesthesia group had low levels of the IL-6 24 h after surgery, the deep general anesthesia was not associated to a positive effect on patients' peripheral T lymphocytes during colorectal cancer surgery. We found no evidence that peripheral T lymphocyte subsets and natural killer cells were affected by the targeting a BIS of either 55 or 35 in patients undergoing laparoscopic colorectal cancer surgery in this trial.

TRIAL REGISTRATION

ChiCTR2200056624 ( www.chictr.org.cn ).

The VEGF/VEGFR Axis Revisited: Implications for Cancer Therapy

The vascular endothelial growth factor (VEGF)/vascular endothelial growth factor receptor (VEGFR) axis is indispensable in the process of angiogenesis and has been implicated as a key driver of tumor vascularization. Consequently, several strategies that target VEGF and its cognate receptors, VEGFR-1 and VEGFR-2, have been designed to treat cancer. While therapies targeting full-length VEGF have resulted in an improvement in both overall survival and progression-free survival in various cancers, these benefits have been modest. In addition, the inhibition of VEGFRs is associated with undesirable off-target effects. Moreover, VEGF splice variants that modulate sprouting and non-sprouting angiogenesis have been identified in recent years. Cues within the tumor microenvironment determine the expression patterns of these variants. Noteworthy is that the mechanisms of action of these variants challenge the established norm of VEGF signaling. Furthermore, the aberrant expression of some of these variants has been observed in several cancers. Herein, developments in the understanding of the VEGF/VEGFR axis and the splice products of these molecules, as well as the environmental cues that regulate these variants are reviewed. Furthermore, strategies that incorporate the targeting of VEGF variants to enhance the effectiveness of antiangiogenic therapies in the clinical setting are discussed.

Molecular Pathogenesis of Colorectal Cancer: Impact of Oncogenic Targets Regulated by Tumor Suppressive miR-139-3p

We recently determined the RNA sequencing-based microRNA (miRNA) expression signature of colorectal cancer (CRC). Analysis of the signature showed that the expression of both strands of pre-miR-139 (miR-139-5p, the guide strand, and miR-139-3p, the passenger strand) was significantly reduced in CRC tissues. Transient transfection assays revealed that expression of miR-139-3p blocked cancer cell malignant transformation (e.g., cell proliferation, migration, and invasion). Notably, expression of miR-139-3p markedly blocked RAC-alpha serine/threonine-protein kinase (AKT) phosphorylation in CRC cells. A combination of in silico database and gene expression analyses of miR-139-3p-transfected cells revealed 29 putative targets regulated by miR-139-3p in CRC cells. RNA immunoprecipitation analysis using an Argonaute2 (AGO2) antibody revealed that KRT80 was efficiently incorporated into the RNA-induced silencing complex. Aberrant expression of Keratin 80 (KRT80) was detected in CRC clinical specimens by immunostaining. A knockdown assay using small interfering RNA (siRNA) targeting KRT80 showed that reducing KRT80 expression suppressed the malignant transformation (cancer cell migration and invasion) of CRC cells. Importantly, inhibiting KRT80 expression reduced AKT phosphorylation in CRC cells. Moreover, hexokinase-2 (HK2) expression was reduced in cells transfected with the KRT80 siRNAs or miR-139-3p. The involvement of miRNA passenger strands (e.g., miR-139-3p) in CRC cells is a new concept in miRNA studies. Our tumor-suppressive miRNA-based approach helps elucidate the molecular pathogenesis of CRC.

Influence of stathmin 1 (STMN1) expression on neoangiogenesis in colorectal adenocarcinoma

Stathmin1 is a microtubular regulatory protein. The expression disorders of this protein result in significant changes in cell migration, invasion, adhesion and colony formation in many malignant tumors. The aim of our research was to investigate the effects of Stathmin1 expression on neoangiogenesis in colorectal adenocarcinoma. Biopsy material that was obtained by the resection of colorectal carcinoma was used. The experimental group consisted of operative biopsies of colorectal cancer (n = 72), and the control group (n = 72) consisted of biopsies of adjacent non-tumor colon tissue. The biopsy material was taken from an operative preparation submitted to the Department of Pathology. After histopathological treatment, classical Hematoxylin- Eosin and immunohistochemical ABC methods with anti-Stathmin1, anti-VEGF and anti CD105 antibodies were applied on 4 µm thick sections. High expression of Stathmin1 is associated with severe (91.9%) and moderate (8.1%) expression of VEGF in a significantly high number of cases. This relation is defined by a highly significant correlation coefficient (r = 0.768; p = 0.000). High expression of Stathmin1 is associated with a high microvascular density index (mvdIDX) in a significant number of cases (73.0%) while low expression of Stathmin1 is in relation with low mvdIDX in a significant 73.7% of cases. This relationship is also defined by a highly significant correlation coefficient (r = 0.566; p = 0.000). ROC analysis showed that the sensitivity for Stathmin1 was 97.4% and the specificity was 91.4%. Based on Stathmin1 expression, it is possible to differentiate patients with increased risk for metastatic disease. The highly significant association of Stathmin1 expression with VEGF expression and microvascular density (MVD) suggests that Stathmin1 may be a serious candidate for therapeutic target.

Classical Angiogenic Signaling Pathways and Novel Anti-Angiogenic Strategies for Colorectal Cancer

Although productive progress has been made in colorectal cancer (CRC) researchs, CRC is the second most frequent type of malignancy and the major cause of cancer-related death among gastrointestinal cancers. As angiogenesis constitutes an important point in the control of CRC progression and metastasis, understanding the key signaling pathways that regulate CRC angiogenesis is critical in elucidating ways to inhibit CRC. Herein, we comprehensively summarized the angiogenesis-related pathways of CRC, including vascular endothelial growth factor (VEGF), nuclear factor-kappa B (NF-κB), Janus kinase (JAK)/signal transducer and activator of transcription (STAT), Wingless and int-1 (Wnt), and Notch signaling pathways. We divided the factors influencing the specific pathway into promoters and inhibitors. Among these, some drugs or natural compounds that have antiangiogenic effects were emphasized. Furthermore, the interactions of these pathways in angiogenesis were discussed. The current review provides a comprehensive overview of the key signaling pathways that are involved in the angiogenesis of CRC and contributes to the new anti-angiogenic strategies for CRC.

Identification of the prognostic signature based on genomic instability-related alternative splicing in colorectal cancer and its regulatory network

Background: Colorectal cancer (CRC) is a heterogeneous disease with many somatic mutations defining its genomic instability. Alternative Splicing (AS) events, are essential for maintaining genomic instability. However, the role of genomic instability-related AS events in CRC has not been investigated.

Methods: From The Cancer Genome Atlas (TCGA) program, we obtained the splicing profiles, the single nucleotide polymorphism, transcriptomics, and clinical information of CRC. Combining somatic mutation and AS events data, a genomic instability-related AS signature was constructed for CRC. Mutations analyses, clinical stratification analyses, and multivariate Cox regression analyses evaluated this signature in training set. Subsequently, we validated the sensitivity and specificity of this prognostic signature using a test set and the entire TCGA dataset. We constructed a nomogram for the prognosis prediction of CRC patients. Differentially infiltrating immune cells were screened by using CIBERSORT. Inmmunophenoscore (IPS) analysis was used to evaluate the response of immunotherapy. The AS events-related splicing factors (SF) were analyzed by Pearson’s correlation. The effects of SF regulating the prognostic AS events in proliferation and migration were validated in Caco2 cells.

Results: A prognostic signature consisting of seven AS events (PDHA1-88633-ES, KIAA1522-1632-AP, TATDN1-85088-ES, PRMT1-51042-ES, VEZT-23786-ES, AIG1-77972-AT, and PHF11-25891-AP) was constructed. Patients in the high-risk score group showed a higher somatic mutation. The genomic instability risk score was an independent variable associated with overall survival (OS), with a hazard ratio of a risk score of 1.537. The area under the curve of receiver operator characteristic curve of the genomic instability risk score in predicting the OS of CRC patients was 0.733. Furthermore, a nomogram was established and could be used clinically to stratify patients to predict prognosis. Patients defined as high-risk by this signature showed a lower proportion of eosinophils than the low-risk group. Patients with low risk were more sensitive to anti-CTLA4 immunotherapy. Additionally, HSPA1A and FAM50B were two SF regulating the OS-related AS. Downregulation of HSPA1A and FAM50B inhibited the proliferation and migration of Caco2 cells.

Conclusion: We constructed an ideal prognostic signature reflecting the genomic instability and OS of CRC patients. HSPA1A and FAM50B were verified as two important SF regulating the OS-related AS.

Application of Bevacizumab Combined With Chemotherapy in Patients With Colorectal Cancer and Its Effects on Brain-Gut Peptides, Intestinal Flora, and Oxidative Stress

Objective

To investigate the efficacy of bevacizumab combined with chemotherapy in the treatment of colorectal cancer (CRC) and to analyze the effects on brain peptides, intestinal flora, and oxidative stress in CRC patients.

Methods

Eighty two patients with CRC who were admitted to our hospital from March 2018 to June 2021 were selected as the research subjects and divided into the control group (n = 41) and the observation group (n = 41). The control group was treated with XELOX chemotherapy, and the observation group was additionally treated with bevacizumab, which was repeated every 3 weeks for a total of two treatments. The therapeutic effects of the two groups were evaluated after treatment. The brain-gut peptide index, intestinal flora index and oxidative stress index were detected, and the adverse reactions of the two groups were recorded.

Results

In the control group, ER was 36.59% (15/41) and DCR was 73.17% (30/41). In the observation group, ER was 63.41% (26/41) and DCR was 90.24% (37/41). ER and DCR in the observation group were higher than those in the control group (P < 0.05). After treatment, the levels of motilin and gastrin in the observation group were lower than those in the control group, and ghrelin was higher than that in the control group (P < 0.05). After treatment, the levels of Bifidobacterium, Lactobacilli and Enterococcus in the observation group were higher than those in the control group, and the level of Escherichia coli was lower than that in the control group (P < 0.05). After treatment, the SOD level of the observation group was lower than that of the control group, and the MDA level was higher than that of the control group.

Conclusion

Bevacizumab combined with chemotherapy has good efficacy in the treatment of colorectal cancer patients, which can effectively improve the gastrointestinal motility of patients, regulate the intestinal flora of the body, rebuild the microecological balance, effectively reduce the oxidative stress response of patients, and reduce the incidence of adverse reactions.

Identification of a Nomogram with an Autophagy-Related Risk Signature for Survival Prediction in Patients with Glioma

Background

Glioma is a common type of tumor in the central nervous system characterized by high morbidity and mortality. Autophagy plays vital roles in the development and progression of glioma, and is involved in both normal physiological and various pathophysiological progresses.

Patients and Methods

A total of 531 autophagy-related genes (ARGs) were obtained and 1738 glioma patients were collected from three public databases. We performed least absolute shrinkage and selection operator regression to identify the optimal prognosis-related genes and constructed an autophagy-related risk signature. The performance of the signature was validated by receiver operating characteristic analysis, survival analysis, clinic correlation analysis, and Cox regression. A nomogram model was established by using multivariate Cox regression analysis. Schoenfeld’s global and individual test were used to estimate time-varying covariance for the assumption of the Cox proportional hazard regression analysis. The R programming language was used as the main data analysis and visualizing tool.

Results

An overall survival-related risk signature consisting of 15 ARGs was constructed and significantly stratified glioma patients into high- and low-risk groups (P < 0.0001). The area under the ROC curve of 1-, 3-, 5-year survival was 0.890, 0.923, and 0.889, respectively. Univariate and multivariate Cox analyses indicated that the risk signature was a satisfactory independent prognostic factor. Moreover, a nomogram model integrating risk signature with clinical information for predicting survival rates of patients with glioma was constructed (C-index=0.861±0.024).

Conclusion

This study constructed a novel and reliable ARG-related risk signature, which was verified as a satisfactory prognostic marker. The nomogram model could provide a reference for individually predicting the prognosis for each patient with glioma and promoting the selection of optimal treatment.

VEGF gene polymorphisms regulate human retinal vascular endothelial cell proliferation and apoptosis through ASF/SF2-associated alternative splicing

This study investigated the effects of single nucleotide polymorphisms (SNPs) of the VEGF （vascular endothelial growth factor） gene, which are associated with susceptibility to age-related macular degeneration (AMD), on the expression of VEGF proteins (VEGF₁₆₅ and VEGF_165b) and their role in cell proliferation and apoptosis in human retinal vascular endothelial cells (hRVECs). Cell viability and VEGF₁₆₅ and VEGF_165b expressions were evaluated in hRVECs transfected with VEGF genes containing different SNPs (rs3025039, rs3025033, and rs10434). The Cell Counting Kit 8 assay, quantitative real-time PCR, western blotting, TUNEL assay, and enzyme-linked immunosorbent assay were used to examine the effects of VEGF gene SNPs on cell viability, VEGF₁₆₅ and VEGF_165b expressions, and cell apoptosis in hRVECs. The interaction and localization of the RNA-binding protein alternative splicing factor/splicing factor 2 (ASF/SF2) were assessed using RNA pull-down. Although VEGF₁₆₅ expression decreased, VEGF_165b levels increased significantly in hRVECs transfected with rs3025039, which decreased cell viability and induced apoptosis. The SNPs rs3025033 and rs10434 had no significant effects on VEGF_165b protein production and apoptosis; however, they promoted cell proliferation. SNPs affected the interaction between RNA and ASF/SF2, a splicing factor for intron retention. Insulin-like growth factor-1 treatment induced the expression of VEGF₁₆₅, but not VEGF_165b, whereas SRPIN340 treatment, an inhibitor of ASF/SF2, increased VEGF_165b protein levels. VEGF gene sequence variations affected hRVEC proliferation and apoptosis via alternative gene splicing. Thus, the regulation of splicing via ASF/SF2 could be a potential strategy in treating pathological neovascularization in patients with AMD.

Growth Factors, PI3K/AKT/mTOR and MAPK Signaling Pathways in Colorectal Cancer Pathogenesis: Where Are We Now?

Colorectal cancer (CRC) is a predominant malignancy worldwide, being the fourth most common cause of mortality and morbidity. The CRC incidence in adolescents, young adults, and adult populations is increasing every year. In the pathogenesis of CRC, various factors are involved including diet, sedentary life, smoking, excessive alcohol consumption, obesity, gut microbiota, diabetes, and genetic mutations. The CRC tumor microenvironment (TME) involves the complex cooperation between tumoral cells with stroma, immune, and endothelial cells. Cytokines and several growth factors (GFs) will sustain CRC cell proliferation, survival, motility, and invasion. Epidermal growth factor receptor (EGFR), Insulin-like growth factor -1 receptor (IGF-1R), and Vascular Endothelial Growth Factor -A (VEGF-A) are overexpressed in various human cancers including CRC. The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) and all the three major subfamilies of the mitogen-activated protein kinase (MAPK) signaling pathways may be activated by GFs and will further play key roles in CRC development. The main aim of this review is to present the CRC incidence, risk factors, pathogenesis, and the impact of GFs during its development. Moreover, the article describes the relationship between EGF, IGF, VEGF, GFs inhibitors, PI3K/AKT/mTOR-MAPK signaling pathways, and CRC.

Alternative splicing of mRNA in colorectal cancer: new strategies for tumor diagnosis and treatment

Alternative splicing (AS) is an important event that contributes to posttranscriptional gene regulation. This process leads to several mature transcript variants with diverse physiological functions. Indeed, disruption of various aspects of this multistep process, such as cis- or trans- factor alteration, promotes the progression of colorectal cancer. Therefore, targeting some specific processes of AS may be an effective therapeutic strategy for treating cancer. Here, we provide an overview of the AS events related to colorectal cancer based on research done in the past 5 years. We focus on the mechanisms and functions of variant products of AS that are relevant to malignant hallmarks, with an emphasis on variants with clinical significance. In addition, novel strategies for exploiting the therapeutic value of AS events are discussed.

NSD2 promotes tumor angiogenesis through methylating and activating STAT3 protein

Tumor angiogenesis plays vital roles in tumorigenesis and development; regulatory mechanism of angiogenesis is still not been fully elucidated. NSD2, a histone methyltransferase catalyzing di-methylation of histone H3 at lysine 36, has been proved a critical molecule in proliferation, metastasis, and tumorigenesis. But its role in tumor angiogenesis remains unknown. Here we demonstrated that NSD2 promoted tumor angiogenesis in vitro and in vivo. Furthermore, we confirmed that the angiogenic function of NSD2 was mediated by STAT3. Momentously, we found that NSD2 promoted the methylation and activation of STAT3. In addition, mass spectrometry and site-directed mutagenesis assays revealed that NSD2 methylated STAT3 at lysine 163 (K163). Meanwhile, K to R mutant at K163 of STAT3 attenuated the activation and angiogenic function of STAT3. Taken together, we conclude that methylation of STAT3 catalyzed by NSD2 promotes the activation of STAT3 pathway and enhances the ability of tumor angiogenesis. Our findings investigate a NSD2-dependent methylation-phosphorylation regulation pattern of STAT3 and reveal that NSD2/STAT3/VEGFA axis might be a potential target for tumor therapy.

Influence of KDR Genetic Variation on the Efficacy and Safety of Patients with Chemotherapy Refractory Metastatic CRC Who Received Apatinib Treatment

Background

The aim of the present study was to investigate the influence of kinase insert domain containing receptor (KDR) genetic variation on the efficacy of treatment and safety of patients with chemotherapy-refractory metastatic colorectal cancer (CRC) receiving apatinib.

Methods

A total of 108 patients with chemotherapy refractory metastatic CRC who were treated with apatinib participated in this study retrospectively. Efficacy of the patients' treatment was evaluated. Prognosis was carried out and safety profile was documented, respectively. Blood specimens and peripheral blood mononuclear cells (PBMC) of the patients were obtained for the analysis of genetic variation and KDR gene mRNA expression, respectively. The association between genotype status and clinical outcomes was presented.

Results

Objective response rate (ORR) and disease control rate (DCR) of the 108 patients with metastatic CRC receiving apatinib treatment were 5.6% and 69.4%, respectively. Survival analysis results exhibited that the median progression-free survival (PFS) and overall survival (OS) of the 108 patients with metastatic CRC was 3.6 months (95% confidence interval (CI): 3.03-4.17 months) and 8.9 months (95% CI: 7.57-10.23 months), respectively. Subsequently, the analysis of KDR genetic variation indicated that rs2071559 was of clinical significance. The minor allele frequency of rs2071559 was 0.22 and the genotype status corresponded with Hardy-Weinberg equilibrium (P=0.949). Prognosis analysis in a dominant inheritance manner through the combination of patients with TC and CC genotype showed that the median PFS of patients with TT genotype and TC/CC genotype was 4.1 and 3.0 months, respectively (P=0.012). Furthermore, the median OS of patients with the two genotypes was 10.5 and 6.1 months, respectively (P=0.007). Additionally, multivariate Cox regression analysis of OS showed that TC/CC genotype was an independent factor for OS (Hazard ratio (HR)=0.65, P=0.021). Interestingly, mRNA expression analysis suggested that the mRNA expression of KDR in PBMC differed significantly according to rs2071559 genotype status (P<0.001).

Conclusion

Apatinib demonstrated a potentially superior clinical outcome for patients with chemotherapy-refractory metastatic CRC. KDR polymorphism rs2071559 could be used as a potential biomarker for the prognosis evaluation of patients with CRC receiving apatinib therapy.

New insights into molecular pathways in colorectal cancer: Adiponectin, interleukin-6 and opioid signaling

Colorectal cancer (CRC) is one of the most common cause of death among neoplasms around the world. The environmental factors, like diet and obesity, are crucial in CRC pathogenesis by creating cancer-favorable microenvironment and hormonal changes. Adiponectin, the adipose tissue-specific hormone, is generally considered to negatively correlate with CRC development. The interleukin 6 (IL-6) is one of the most important pro-inflammatory cytokine connected with CRC, which is strongly inflammation-associated. The opioids are variable group substantially correlated with cancers - the endogenous opioids affect immune system and cell cycle including proliferation and cell death whereas exogenous opioids are leading clinically used analgesics in terminal cancer patients. In this review we discuss the involvement of adiponectin, IL-6 and opioids in CRC pathogenesis, their link with obesity, possible cross-talk and potential novel therapeutic approach in CRC treatment.

Mechanisms of Core Chinese Herbs against Colorectal Cancer: A Study Based on Data Mining and Network Pharmacology

Colorectal cancer (CRC) is now the second most deadly cancer globally. Chinese herbal medicine (CHM) plays an indispensable role in CRC treatment in China. However, the core herbs (the CHs) in the treatment of CRC and their underlying therapeutic mechanisms remain unclear. This study aims to uncovering the CHs and their mechanisms of action of CRC treatment, applying data mining and network pharmacology approach. First, CHM prescriptions treating CRC were collected from clinical studies from the Chinese National Knowledge Infrastructure (CNKI) and MEDLINE databases, and the CHs were identified through data mining. Then, the bioactive compounds and the corresponding putative targets of the CHs were obtained from three traditional Chinese medicine (TCM) databases. CRC related targets were acquired from three disease databases; the overlapping targets between the CHs and CRC were identified as the therapeutic targets. Subsequently, functional enrichment analysis was performed to elucidate the mechanisms of the CHs on CRC. Moreover, networks were constructed to screen the major bioactive compounds and therapeutic targets. Finally, prognostic values of the major target genes were evaluated by survival analysis, and molecular docking simulation was performed to assess the binding affinity of key targets and major bioactive compounds. It came out that 10 the CHs from 113 prescriptions and 190 bioactive compounds with 118 therapeutic targets were identified. The therapeutic targets were mainly enriched in the biological progress of transcription, apoptosis, and response to cytokine. Various cancer-associated signaling pathways, including microRNAs, TNF, apoptosis, PI3K-Akt, and p53, were involved. Furthermore, 15 major bioactive compounds and five key target genes (VEGFA, CASP3, MYC, CYP1Y1, and NFKB1) with prognostic significance were identified. Additionally, most major bioactive compounds might bind firmly to the key target proteins. This study provided an overview of the anti-CRC mechanisms of the CHs, which might refer to the regulation of apoptosis, transcription, and inflammation.

High preoperative levels of circulating SFRP5 predict better prognosis in colorectal cancer patients

The purpose of this research was to investigate the diagnostic and prognostic value of circulating SFRP5 (cSFRP5) in colorectal cancer (CRC). We evaluated preoperative cSFRP5 levels in CRC patients and controls (n = 208). We found significantly higher cSFRP5 levels in CRC patients compared with non-CRC controls (p < 0.001). Levels of cSFRP5 were significantly lower in CRC patients with either vascular invasion (p = 0.001) or liver metastasis (p = 0.016). High cSFRP5 levels were associated with longer disease-free survival in both univariate (p = 0.024) and multivariate (p = 0.015) analyses. Analysis of an independent tissue cohort from The Cancer Genome Atlas database revealed significantly lower SFRP5 RNA expression in CRC tumor tissue compared with adjacent normal mucosa (n = 590 vs 47; p < 0.0001). Our findings confirm the role of cSFRP5 as a physiologic tumor suppressor and demonstrate its potential diagnostic and prognostic value in CRC.

Triterpenoids from Liquidambar Fructus induced cell apoptosis via a PI3K-AKT related signal pathway in SMMC7721 cancer cells

A previously undescribed taraxerene-type triterpenoid possessing a class of rare natural taraxerene triterpenoid possessing skeleton with 14, 28-lactone, two undescribed oleane-type triterpenoids, and twenty-five known triterpenoids were isolated from Liquidambar formosana (Hamamelidaceae). The structures of undescribed compounds were determined on the basis of 1D and 2D NMR spectroscopic, HR-ESI-MS, and X-ray crystallographic data analysis. Among the isolates, ursolic acid, 3,6-dion-20(29)-lupen-28-oic acid, and 3-oxo-12α-hydroxyoleanan-28,13β-olide induced a significant apoptosis in SMMC7721 cells in the flow cytometer experiment with apoptosis rates of 94.5%, 57.3% and 89.9% at 8.0 μM, respectively, exhibiting near equivalent apoptosis-inducing abilities to that positive drug taxol (apoptotic rate of 71.2% at 1.4 μM). Mechanism studies suggested that these three compounds could regulate the mitochondrial pathway by up-regulating the expressions of pro-apoptotic factors (Bad and Bax) and activating caspase-3 and caspase-9 to induce apoptosis. Further studies indicated that the pro-apoptotic effects of these three compounds were associated with PI3K-AKT pathway inhibition. Taken together, these studies provide evidence that triterpenoids from L. Fructus are promising candidates for the hepatocellular carcinoma therapy.

Association of Polyps with Early-Onset Colorectal Cancer and Throughout Surveillance: Novel Clinical and Molecular Implications

Early-onset colorectal cancer (EOCRC) is an increasing and worrisome entity. The aim of this study was to analyze its association with polyps concerning prognosis and surveillance. EOCRC cases were compared regarding the presence or absence of associated polyps (clinical and molecular features), during a minimum of 7 years of follow-up. Of 119 cases, 56 (47%) did not develop polyps (NP group), while 63 (53%) did (P group). The NP group showed a predominant location of the CRC in the rectum (50%), of sporadic cases (54%), and diagnosis at advanced stages: Only P53 and SMARCB1 mutations were statistically linked to this group. The P group, including mainly early-diagnosed tumors, was linked with the most frequent and differential altered chromosomal regions in the array comparative genomic hybridization. The two most frequent groups according to the follow-up were the NP group (40%), and patients developing polyps in the first 5 years of follow-up (P < 5FU) (34%) (these last groups predominantly diagnosed at the earliest stage and with adenomatous polyps (45%)). EOCRC with polyps that developed during the entire follow-up (PDFU group) were mainly located in the right colon (53%), diagnosed in earlier stages, and 75% had a familial history of CRC. Patients developing polyps after the first 5 years (P > 5FU) showed a mucinous component (50%). Our results show that the absence or presence of polyps in EOCRC is an important prognostic factor with differential phenotypes. The development of polyps during surveillance shows that it is necessary to extend the follow-up time, also in those cases with microsatellite-stable EOCRC.

Peripheral blood mononuclear cells extracts VEGF protein levels and VEGF mRNA: Associations with inflammatory molecules in a healthy population

Background

Vascular endothelial growth factor (VEGF) is a signal protein, implicated in various physiological and pathophysiological processes together with other common inflammatory biomarkers. However, their associations have not yet been fully elucidated. In the present study, we investigated associations between VEGF and four specific VEGF mRNA isoforms with levels of 11 inflammation molecules, derived from peripheral blood mononuclear cells (PBMCs) extracts.

Methods

Healthy participants from the STANISLAS Family Study (n = 285) were included. Levels of VEGF (four mRNA isoforms and protein levels) and inflammatory molecules (IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, INF-γ, TNF-α, MCP-1, EGF) were measured in PBMCs extracts. Multiple regression analyses were performed, adjusted for age and gender.

Results

The analyses revealed significant associations between VEGF protein levels and levels of IL-4 (β = 0.028, P = 0.013), MCP-1 (β = 0.015, P<0.0001) and EGF (β = 0.017, P<0.0001). Furthermore, mRNA isoform VEGF₁₆₅ was associated with MCP-1 and IL-1α (P = 0.002 and P = 0.008, respectively); and mRNA isoform VEGF₁₈₉ was associated with IL-4 and IL-6 (P = 0.019 and P = 0.034, respectively).

Conclusions

To our knowledge, the present study represents the first investigation that successfully demonstrates links between VEGF protein levels and inflammatory molecules levels derived from PBMCs extracts and identifies associations between specific VEGF mRNA isoforms and inflammatory molecules.

Impact

These findings provide novel insights that may assist in the development of new tissue and mRNA isoform specific measurements of VEGF levels, which may positively contribute to predicting the risk of common complex diseases and response of currently used anti-VEGF agents, and developing of novel targeted therapies for VEGF-related pathophysiology.

BRD4 Inhibitor AZD5153 Suppresses the Proliferation of Colorectal Cancer Cells and Sensitizes the Anticancer Effect of PARP Inhibitor

Background: Bromodomain-containing protein 4(BRD4) is reported to play a vital role in the development of numerous malignant diseases, which is considered as a promising target for cancer therapy. AZD5153, a novel specific BRD4 inhibitor, showed potent anticancer effects in several cancer types, but its therapeutic potential has not been fully evaluated in colorectal cancer cells. Objective: We sought to evaluate the therapeutic potential of BRD4 inhibition of by AZD5153 and its combined anticancer cancer effect with PARP inhibitor BMN673 in vitro and in vivo in colorectal cancer. Methods: We analyzed The Cancer Genome Atlas (TCGA) database to investigate BRD4 expression in colorectal cancer patient. Clonogenic assays 、MTT assays and PI/Annexin V staining were used to determine the effect of AZD5153 and BMN673 and combination therapy on cell viability and apoptosis induction. Western blotting was applied to detect relevant molecules changes. Propidium iodide staining was performed to examine cell cycle distributions after monotherapy or combination therapy. Nude mice xenograft model was generated to confirm the therapeutic effect of AZD5153 and BMN673 combination in vivo, and IHC staining was used to detect the expression level of BRD4 and related markers in colorectal patient and xenograft. Results: Analysis of TCGA database indicated that BRD4 was overexpressed in colorectal cancer patient. The clonogenic and MTT assays and PI/Annexin V staining demonstrated that AZD5153 significantly suppressed cell proliferation and induced apoptosis in colorectal cancer cells HCT116 and LoVo. Western blotting showed that AZD5153 inhibited the expression of c-Myc and increased expression of the apoptosis markers, cleaved caspase-3 and poly(ADP-ribose) polymerase (PARP), besides, we found that BRD4 knockdown could also inhibited cell proliferation and induced cell apoptosis. Moreover, AZD5153 inhibited the expression of Wee1 and impaired G2M cell cycle checkpoint, thus sensitized the anticancer effect of BMN673 in vitro and in vivo. Conclusion: Our data revealed that AZD5153suppressed the proliferation of colorectal cancer cells and sensitized them to the anticancer effect of the PARP inhibitor BMN673 via Wee1 inhibition in vitro and in vivo. This suggested that targeting BRD4 might be a valuable strategy for colorectal cancer treatment.

Bevacizumab or fibronectin gene editing inhibits the osteoclastogenic effects of fibroblasts derived from human radicular cysts

Fibronectin (FN) is a main component of extracellular matrix (ECM) in most adult tissues. Under pathological conditions, particularly inflammation, wound healing and tumors, an alternatively spliced exon extra domain A (EDA) is included in the FN protein (EDA⁺FN), which facilitates cellular proliferation, motility, and aggressiveness in different lesions. In this study we investigated the effects of EDA⁺FN on bone destruction in human radicular cysts and explored the possibility of editing FN gene or blocking the related paracrine signaling pathway to inhibit the osteoclastogenesis. The specimens of radicular cysts were obtained from 20 patients. We showed that the vessel density was positively associated with both the lesion size (R = 0.49, P = 0.001) and EDA⁺FN staining (R = 0.26, P = 0.022) in the specimens. We isolated fibroblasts from surgical specimens, and used the CRISPR/Cas system to knockout the EDA exon, or used IST-9 antibody and bevacizumab to block EDA⁺FN and VEGF, respectively. Compared to control fibroblasts, the fibroblasts from radicular cysts exhibited significantly more Trap⁺MNCs, the relative expression level of VEGF was positively associated with both the ratio of EDA⁺FN/total FN (R = 0.271, P = 0.019) and with the number of Trap⁺MNCs (R = 0.331, P = 0.008). The knockout of the EDA exon significantly decreased VEGF expression in the fibroblasts derived from radicular cysts, leading to significantly decreased osteoclastogenesis; similar results were observed using bevacizumab to block VEGF, but block of EDA⁺FN with IST-9 antibody had no effect. Furthermore, the inhibitory effects of gene editing on Trap⁺MNC development were restored by exogenous VEGF. These results suggest that EDA⁺FN facilitates osteoclastogenesis in the fibrous capsule of radicular cysts, through a mechanism mediated by VEGF via an autocrine effect on the fibroblasts. Bevacizumab inhibits osteoclastogenesis in radicular cysts as effectively as the exclusion of the EDA exon by gene editing.

Inhibitory effects of Chanling Gao on the proliferation and liver metastasis of transplanted colorectal cancer in nude mice

This study aimed to explore the efficacy and mechanism of Chanling Gao (CLG), a compound Chinese medicine, on colorectal cancer (CRC). A model of transplanted CRC was established in nude mice. The mice were treated 7 days after CRC transplantation with either Capecitabine or CLG for 3 weeks. On the 28th day after the operation, CRC growth and liver metastasis were assessed by morphology, the changes in the expression of HIF-1α (hypoxia inducible factor-1α), stromal cell-derived factor-1 alpha (SDF-1α), CXCR4 (C-X-C chemokine receptor type 4), PI3K, and Akt in the transplanted tumor and SDF-1α and CXCR4 in the liver were detected by Western blot and immunohistochemistry. The protein contents of vascular endothelial growth factor (VEGF), matrix metalloproteinase (MMP)-2, and collagen IV in the serum and transplanted tumor and SDF-1α and CXCR4 in liver tissues were detected by enzyme-linked immunosorbent assay. In the Capecitabine and high dose CLG groups, the growth and liver metastasis of CRC were significantly inhibited, the protein levels of HIF-1α, SDF-1α, CXCR4, MMP-2, VEGF, PI3K, Akt, P-PI3K and P-Akt in the transplanted tumor were lower, while the content of collagen IV in the transplanted tumor was higher, than in Model group. A high dose of CLG inhibited the growth of transplanted tumor and liver metastasis of CRC in nude mice, probably by inhibiting the HIF-1α/SDF-1α-CXCR4/PI3K-Akt signaling pathway reducing the synthesis and release of VEGF and degradation of collagen IV.

Function, clinical application, and strategies of Pre-mRNA splicing in cancer

Pre-mRNA splicing is a fundamental process that plays a considerable role in generating protein diversity. Pre-mRNA splicing is also the key to the pathology of numerous diseases, especially cancers. In this review, we discuss how aberrant splicing isoforms precisely regulate three basic functional aspects in cancer: proliferation, metastasis and apoptosis. Importantly, clinical function of aberrant splicing isoforms is also discussed, in particular concerning drug resistance and radiosensitivity. Furthermore, this review discusses emerging strategies how to modulate pathologic aberrant splicing isoforms, which are attractive, novel therapeutic agents in cancer. Last we outline current and future directions of isoforms diagnostic methodologies reported so far in cancer. Thus, it is highlighting significance of aberrant splicing isoforms as markers for cancer and as targets for cancer therapy.

4'-hydroxywogonin inhibits colorectal cancer angiogenesis by disrupting PI3K/AKT signaling

Angiogenesis is fundamental for solid tumor growth and metastasis, and anti-angiogenic therapy has been an important therapeutic option for cancer treatment. Colorectal cancer (CRC) represents the fourth leading cause of cancer-related death worldwide. The current studies were aimed at investigating the anti-angiogenic effects of the natural compound 4'-hydroxywogonin (4'-HW) on CRC-related angiogenesis. Human CRC cell line SW620 cells and normal human intestinal epithelial HIEC cells were cultured and treated with interleukin-6 to mimic the tumor inflammatory microenvironment. Our data showed that 4'-HW reduced the viability of SW620 cells in a concentration- and time-dependent manner. 4'-HW also suppressed the proliferation of SW620 cells, but had little effect on the viability of HIEC cells. Moreover, 4'-HW concentration-dependently decreased the mRNA and protein expression of vascular endothelial growth factor-A (VEGF-A), the predominant pro-angiogenic cytokine in tumor angiogenesis. Subsequently, 4'-HW concentration-dependently inhibited the phosphorylation of phosphatidylinositol 3-kinase (PI3K) and AKT. PI3K inhibitor wortmannin, similar to 4'-HW, significantly downregulated the VEGF-A expression in SW620 cells, and combination of wortmannin and 4'-HW produced more significant effects. Finally, human umbilical vein endothelial cells (HUVECs) incubated with the conditioned medium of 4'-HW-treated SW620 cells exhibited impaired angiogenic capacity at Matrigel. Incubation with the neutralizing antibody against VEGF-Aalone also suppressed the angiogenic properties of HUVECs in vitro. Collectively, 4'-HW decreased the viability and reduced angiogenesis in CRC, which was associated with downregulation of VEGF-A expression by disrupting the PI3K/AKT pathway. Our discoveries suggested 4'-HW as a promising anticancer agent against CRC targeting angiogenesis.

RAD52 gene polymorphisms are associated with risk of colorectal cancer in a Chinese Han population

Upward trends in the incidence and mortality rates of colorectal cancer (CRC) in China over the past decade mean that it is critical to improve survival outcomes for patients with this malignancy. Analysis of genetic variants may identify biomarkers that have a role in CRC susceptibility and clinical outcomes in Chinese patients with CRC. RAD52 is a key mediator during DNA strand exchange and homologous recombination within mammalian cells. In this study, we explored the effects of RAD52 single nucleotide polymorphisms (SNPs) in the susceptibility and clinicopathological characteristics of Chinese Han patients with CRC. Five RAD52 SNPs (rs1051669, rs10774474, rs11571378, rs6489769, and rs7963551) were analyzed using TaqMan SNP genotyping in 281 patients with CRC and 309 healthy controls. Among those aged over 60 years in the total population, carriers of the variant C allele or at least one T allele of the rs1051669 SNP were at a lower risk of CRC than carriers of the wild-type CC variant of rs1051669, while in those carrying the rs7963551 SNP, the GT or GT+GG alleles were associated with an increased risk of CRC compared with patients carrying TT alleles. We indicated a significant correlation between RAD52 rs7963551 polymorphism and lymph node metastasis in CRC patients. In all patients, the T-T-T-T-T, C-T-T-T-T, and C-T-A-C-T haplotypes were associated with an increasing risk of CRC. Our findings suggest that 4 RAD52 SNPs (rs1051669, rs10774474, rs11571378, and rs6489769) might contribute to the prediction of CRC susceptibility. In conclusion, our study demonstrated that RAD52 polymorphisms were associated with CRC in a Chinese Han cohort.