Targeting Angiogenesis in Colorectal Carcinoma

The Wnt/β-catenin signaling pathway in colorectal cancer: mechanism and intervention of traditional Chinese medicine and chemical compound

Colorectal cancer (CRC) is globally recognized as the third most frequently diagnosed malignancy and the second leading cause of cancer-related mortality. The etiology of CRC is multifactorial, arising from a complex interplay of genetic alterations, environmental exposures, and age-related physiological changes. Among the numerous signaling pathways that regulate cellular homeostasis, the Wnt/β-catenin signaling pathway not only plays a critical role in embryonic development and cell proliferation but also contributes to the initiation and progression of various malignancies, including CRC. Dysregulation of the Wnt/β-catenin signaling pathway is a hallmark of CRC, playing a pivotal role in regulating chemoresistance and driving invasive and metastatic behaviors. Traditional Chinese Medicine (TCM) is characterized by its multi-target and multi-pathway mechanisms. Extensive studies have demonstrated that TCM can inhibit the activity of CRC cells by targeting the Wnt/β-catenin signaling pathway and significantly alleviate symptoms in CRC animal models, demonstrating its potential therapeutic value for the treatment of CRC. This review primarily focuses on the literature published in the past 5 years, retrieved from databases such as PubMed, Web of Science, Scopus, MEDLINE, and Springer, concerning the targeting of the Wnt/β-catenin signaling pathway for the treatment of CRC. It highlights the research progress on TCM monomers (e.g., myricetin, genistein, baicalein), TCM formulations (e.g., Pai-Nong-San (PNS), Jian-Du-Xiao-Sheng Yin (JXY), Zuo-Jin-Wan (ZJW)), and small-molecule inhibitors (e.g., PCDHGA9, Cetuximab, PTK7). Furthermore, the experimental results and conclusions from these studies are thoroughly analyzed and discussed. Through a comprehensive review of the literature, we conclude that TCM exhibits multi-level, multi-target, and multi-faceted effects in the prevention and treatment of CRC. In-depth research into the mechanisms by which TCM targets the Wnt/β-catenin signaling pathway to prevent and treat CRC may provide novel insights into exploring the pathogenesis of CRC and developing new therapeutic agents for CRC.

Comprehensive review of signaling pathways and therapeutic targets in gastrointestinal cancers

Targeted therapy, the milestone in the development of human medicine, originated in 2004 when the FDA approved the first targeted agent bevacizumab for colorectal cancer treatment. This new development has resulted from drug developers moving beyond traditional chemotherapy, and several trials have popped up in the last two decades with an unprecedented speed. Specifically, EGF/EGFR, VEGF/VEGFR, HGF/c-MET, and Claudin 18.2 therapeutic targets have been developed in recent years. Some targets previously thought to be undruggable are now being newly explored, such as the RAS site. However, the efficacy of targeted therapy is extremely variable, especially with the emergence of new drugs and the innovative use of traditional targets for other tumors in recent years. Accordingly, this review provides an overview of the major signaling pathway mechanisms and recent advances in targeted therapy for gastrointestinal cancers, as well as future perspectives.

Immunotherapy in colorectal cancer: Statuses and strategies

Colorectal cancer (CRC) is widely recognized as the third most prevalent malignancy globally and the second leading cause of cancer-related mortality. Traditional treatment modalities for CRC, including surgery, chemotherapy, and radiotherapy, can be utilized either individually or in combination. However, these treatments frequently result in significant side effects due to their non-specificity and cytotoxicity affecting all cells. Moreover, a considerable number of patients face relapses following these treatments. Consequently, it is imperative to explore more efficacious treatment interventions for CRC patients. Immunotherapy, an emerging frontier in oncology, represents a novel therapeutic approach that leverages the body's immune system to target cancer cells. The principal advantage of immunotherapy is its capacity to selectively target cancer cells while minimizing damage to healthy cells. Its recent adoption as a neoadjuvant therapy presents significant potential to transform the treatment landscape for both primary resectable and metastatic CRC. This review endeavors to offer a comprehensive overview of current strategies in CRC immunotherapy, critically analyze existing literature, underscore anticipated outcomes from ongoing clinical trials, and deliberate on the challenges and impediments encountered within the field of immunotherapy.

Unraveling the complexities of colorectal cancer and its promising therapies - An updated review

Colorectal cancer (CRC) continues to be a global health concern, necessitating further research into its complex biology and innovative treatment approaches. The etiology, pathogenesis, diagnosis, and treatment of colorectal cancer are summarized in this thorough review along with recent developments. The multifactorial nature of colorectal cancer is examined, including genetic predispositions, environmental factors, and lifestyle decisions. The focus is on deciphering the complex interactions between signaling pathways such as Wnt/β-catenin, MAPK, TGF-β as well as PI3K/AKT that participate in the onset, growth, and metastasis of CRC. There is a discussion of various diagnostic modalities that span from traditional colonoscopy to sophisticated molecular techniques like liquid biopsy and radiomics, emphasizing their functions in early identification, prognostication, and treatment stratification. The potential of artificial intelligence as well as machine learning algorithms in improving accuracy as well as efficiency in colorectal cancer diagnosis and management is also explored. Regarding therapy, the review provides a thorough overview of well-known treatments like radiation, chemotherapy, and surgery as well as delves into the newly-emerging areas of targeted therapies as well as immunotherapies. Immune checkpoint inhibitors as well as other molecularly targeted treatments, such as anti-epidermal growth factor receptor (anti-EGFR) as well as anti-vascular endothelial growth factor (anti-VEGF) monoclonal antibodies, show promise in improving the prognosis of colorectal cancer patients, in particular, those suffering from metastatic disease. This review focuses on giving readers a thorough understanding of colorectal cancer by considering its complexities, the present status of treatment, and potential future paths for therapeutic interventions. Through unraveling the intricate web of this disease, we can develop a more tailored and effective approach to treating CRC.

The Anti-Metastatic Potential of Aronia Leaf Extracts on Colon Cancer Cells

BACKGROUND/OBJECTIVES

Numerous studies have demonstrated the health benefits of polyphenols found in aronia fruits; however, little is known about how aronia leaf polyphenols impact colorectal cancer (CRC). This study aimed to evaluate the in vitro anti-metastatic and anti-invasive activity of crude aronia leaf extract (ACE) and purified phenolic-rich aronia leaf extract (APE) against two CRC cell lines (SW-480 and HT-29).

METHODS

Migration and invasion potential of ACE and APE were evaluated. Moreover, ELISA and gelatin zymography were performed to detect translational and activity changes in CRC cells after aronia extracts treatment.

RESULTS

We found that a 100 µg/mL concentration of ACE and APE almost entirely downregulated the migration and invasion of SW-480 cells, showing greater effectiveness than HT-29 cells. The observed inhibition was concentration-dependent and statistically significant. Additionally, extracts reduced the product of MMP-2 and MMP-9 gene expression at the protein level and simultaneously inhibited the activity of both MMPs. An APE at 300 µg/mL for SW-480 and 600 µg/mL for HT-29 resulted in a notable reduction in MMP-2 protein synthesis by 72% and 50%, respectively. In contrast, MMP-9 protein synthesis decreased by 48% and 59% in HT-29 cells treated with 300 µg/mL and 600 µg/mL of ACE, respectively. The levels of gelatinase activity were similar for both CRC lines, and the APE tested at a concentration of 300 µg/mL reached almost the IC50 value after 48 h of incubation.

CONCLUSIONS

Based on the presented results, we provided an experimental foundation for future in vitro and in vivo studies on the potential effects and activities of aronia leaves.

A comprehensive view on the fisetin impact on colorectal cancer in animal models: Focusing on cellular and molecular mechanisms

Flavonoids, including fisetin, have been linked to a reduced risk of colorectal cancer (CRC) and have potential therapeutic applications for the condition. Fisetin, a natural flavonoid found in various fruits and vegetables, has shown promise in managing CRC due to its diverse biological activities. It has been found to influence key cell signaling pathways related to inflammation, angiogenesis, apoptosis, and transcription factors. The results of this study demonstrate that fisetin induces colon cancer cell apoptosis through multiple mechanisms. It impacts the p53 pathway, leading to increased levels of p53 and decreased levels of murine double minute 2, contributing to apoptosis induction. Fisetin also triggers the release of important components in the apoptotic process, such as second mitochondria-derived activator of caspase/direct inhibitor of apoptosis-binding protein with low pI and cytochrome c. Furthermore, fisetin inhibits the cyclooxygenase-2 and wingless-related integration site (Wnt)/epidermal growth factor receptor/nuclear factor kappa B signaling pathways, reducing Wnt target gene expression and hindering colony formation. It achieves this by regulating the activities of cyclin-dependent kinase 2 and cyclin-dependent kinase 4, reducing retinoblastoma protein phosphorylation, decreasing cyclin E levels, and increasing p21 levels, ultimately influencing E2 promoter binding factor 1 and cell division cycle 2 (CDC2) protein levels. Additionally, fisetin exhibits various effects on CRC cells, including inhibiting the phosphorylation of Y-box binding protein 1 and ribosomal S6 kinase, promoting the phosphorylation of extracellular signal-regulated kinase 1/2, and disrupting the repair process of DNA double-strand breaks. Moreover, fisetin serves as an adjunct therapy for the prevention and treatment of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α (PIK3CA)-mutant CRC, resulting in a reduction in phosphatidylinositol-3 kinase (PI3K) expression, Ak strain transforming phosphorylation, mTOR activity, and downstream target proteins in CRC cells with a PIK3CA mutation. These findings highlight the multifaceted potential of fisetin in managing CRC and position it as a promising candidate for future therapy development.

The therapeutic impact of programmed death - 1 in the treatment of colorectal cancer

Colorectal cancer (CRC) is the most common type of newly diagnosed cancer. Metastatic spread and multifactorial chemoresistance have limited the benefits of current therapies. Hence, it is imperative to identify new therapeutic agents to increase treatment efficacy. One of CRC's most promising immunotherapeutic targets is programmed death-1 (PD-1), a cell surface receptor that regulates immune responses. In this paper, we provide an overview of the therapeutic impact of PD-1 in the treatment of CRC. Cancer cells can exploit the PD-1 pathway by upregulating its programmed death-ligand 1 (PD-L1) ligand to evade immune surveillance. The binding of PD-L1 to PD-1 inhibits T cell function, leading to tumor immune escape. PD-1 inhibitors, such as pembrolizumab and nivolumab, block the PD-1/PD-L1 interaction. Clinical trials evaluating PD-1 inhibitors in advanced CRC have shown promising results. In patients with microsatellite instability-high (MSI-H) or mismatch repair-deficient (dMMR) tumors characterized by high mutation rates and increased immunogenicity, PD-1 blockade has demonstrated remarkable efficacy. As a result, pembrolizumab and nivolumab have received accelerated approval by regulatory authorities for the treatment of MSI-H/dMMR metastatic CRC. Additionally, combination approaches, such as combining PD-1 inhibitors with other immunotherapies or targeted agents, are being explored. Despite the success of PD-1 inhibitors in CRC, challenges still exist. Immune-related adverse events can occur and require close monitoring. In conclusion, PD-1 inhibitors have demonstrated significant therapeutic impact, particularly in patients with MSI-H/dMMR tumors.

The pathogenicity of vancomycin-resistant Enterococcus faecalis to colon cancer cells

BACKGROUND

The aim of this study was to investigate the pathogenicity of vancomycin-resistant Enterococcus faecalis (VREs) to human colon cells in vitro.

METHODS

Three E. faecalis isolates (2 VREs and E. faecalis ATCC 29212) were cocultured with NCM460, HT-29 and HCT116 cells. Changes in cell morphology and bacterial adhesion were assessed at different time points. Interleukin-8 (IL-8) and vascular endothelial growth factor A (VEGFA) expression were measured via RT-qPCR and enzyme-linked immunosorbent assay (ELISA), respectively. Cell migration and human umbilical vein endothelial cells (HUVECs) tube formation assays were used for angiogenesis studies. The activity of PI3K/AKT/mTOR signaling pathway was measured by Western blotting.

RESULTS

The growth and adhesion of E. faecalis at a multiplicity of infection (MOI) of 1:1 were greater than those at a MOI of 100:1(p < 0.05). Compared to E. faecalis ATCC 29212, VREs showed less invasive effect on NCM460 and HT-29 cells. E. faecalis promoted angiogenesis by secreting IL-8 and VEGFA in colon cells, and the cells infected with VREs produced more than those infected with the standard strain (p < 0.05). Additionally, the PI3K/AKT/mTOR signaling pathway was activated in E. faecalis infected cells, with VREs demonstrating a greater activation compared to E. faecalis ATCC 29212 (p < 0.05).

CONCLUSION

VREs contribute to the occurrence and development of CRC by promoting angiogenesis and activating the PI3K/AKT/mTOR signaling pathway.

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.

Research Progress on the Anticancer Activity of Plant Polysaccharides

Tumor is a serious threat to human health, with extremely high morbidity and mortality rates. However, tumor treatment is challenging, and the development of antitumor drugs has always been a significant research focus. Plant polysaccharides are known to possess various biological activities. They have many pharmacological properties such as immunomodulation, antitumor, antiviral, antioxidative, antithrombotic, and antiradiation effects, reduction of blood pressure and blood sugar levels, and protection from liver injury. Among these effects, the antitumor effect of plant polysaccharides has been widely studied. Plant polysaccharides can inhibit tumor proliferation and growth by inhibiting tumor cell invasion and metastasis, inducing cell apoptosis, affecting the cell cycle, and regulating the tumor microenvironment. They also have the characteristics of safety, high efficiency, and low toxicity, which can alleviate, to a certain extent, the adverse reactions caused by traditional tumor treatment methods such as surgery, radiotherapy, and chemotherapy. Therefore, this paper systematically summarizes the direct antitumor effects of plant polysaccharides, their regulatory effects on the tumor microenvironment, and intervening many common high-incidence tumors in other ways. It also provides data support for the administration of plant polysaccharides in modern tumor drug therapy, enabling the identification of new targets and development of new drugs for tumor therapy.

Gallocin-derived Engineered Peptides Targeting EGFR and VEGFR in Colorectal Cancer: A Bioinformatic Approach

BACKGROUND

Colorectal cancer (CRC) treatment using time-saving and cost-effective targeted therapies with high selectivity and low toxicity drugs, is a great challenge. In primary investigations on Gallocin, as the most proposed factor in CRC pathogenesis caused by Streptococcus gallolyticus, it was surprisingly found that this bacteriocin has four α-helix structures and some anti-cancer sequences.

OBJECTIVE

The aim of this study was to determine the ability of Gallocin-based anticancer peptides (ACPs) against epidermal growth factor receptor (EGFR) and vascular epidermal growth factor receptor (VEGFR) and the evaluation of their pharmacokinetic properties using bioinformatic approaches.

METHODS

Support vector machine algorithm web-based tools were used for predicting ACPs. The physicochemical characteristics and the potential of anti-cancer activity of Gallocin-derived ACPs were determined by in silico tools. The 3D structure of predicted ACPs was modeled using modeling tools. The interactions between predicted ACPs and targets were investigated by molecular docking exercises. Then, the stability of ligand-receptor interactions was determined by molecular dynamic simulation. Finally, ADMET analysis was carried out to check the pharmacokinetic properties and toxicity of ACPs.

RESULTS

Four amino acid sequences with anti-cancer potential were selected. Through molecular docking, Pep2, and Pep3 gained the best scores, more binding affinity, and strong attachments by the formation of reasonable H-bonds with both EGFR and VEGFR. Molecular simulation confirmed the stability of Pep3- EGFR. According to pharmacokinetic analysis, the ACPs were safe and truthful.

CONCLUSION

Designed peptides can be nominated as drugs for CRC treatment. However, different in-vitro and in-vivo assessments are required to approve this claim.

Discovery of a Dual Tubulin and Neuropilin-1 (NRP1) Inhibitor with Potent In Vivo Anti-Tumor Activity via Pharmacophore-based Docking Screening, Structure Optimization, and Biological Evaluation

Dual inhibition of tubulin and neuropilin-1 (NRP1) may become an effective method for cancer treatment by simultaneously killing tumor cells and inhibiting tumor angiogenesis. Herein, we identified dual tubulin/NRP1-targeting inhibitor TN-2, which exhibited good inhibitory activity against both tubulin polymerization (IC50 = 0.71 ± 0.03 μM) and NRP1 (IC50 = 0.85 ± 0.04 μM). Importantly, it significantly inhibited the viability of several human prostate tumor cell lines. Further mechanism studies indicated that TN-2 could inhibit tubulin polymerization and cause G2/M arrest, thereby inducing cell apoptosis. It could also suppress cell tube formation, migration, and invasion. Moreover, TN-2 showed obvious antitumor effects on the PC-3 cell-derived xenograft model with negligible side effects and good pharmacokinetic profiles. These data demonstrate that TN-2 could be a promising dual-target chemotherapeutic agent for the treatment of prostate cancer.

MEX3A promotes angiogenesis in colorectal cancer via glycolysis

As a gastrointestinal malignancy, colorectal cancer (CRC) is a main cause of cancer-related deaths worldwide. Mex-3 RNA-binding family member A (MEX3A) is upregulated in multiple types of tumors and plays a critical role in tumor proliferation and metastasis. However, the function of MEX3A in CRC angiogenesis has not been fully understood. Hence, the aim of this study was to explore the role of MEX3A in CRC angiogenesis and investigate its underlying mechanisms. MEX3A expression in CRC was first investigated by bioinformatics means and then measured by qRT-PCR and Western blot. CCK-8 assay was employed to test cell viability. Angiogenesis assay was used to assess angiogenesis. The protein levels of VEGF, FGF and SDF-1 were evaluated using Western blot. The expression levels of MYC, HK2 and PGK1 were investigated by qRT-PCR. Extracellular acidification rate (ECAR) and oxygen consumption rate (OCR) were determined by Seahorse XP 96. The levels of pyruvate, lactate, citric acid and malate were measured by corresponding kits. Bioinformatics analysis demonstrated high MEX3A expression in CRC tissues and MEX3A enrichment in glycolysis and angiogenesis pathways. Cell assays showed high MEX3A expression in CRC cells and its promoting effects in CRC cell proliferation and glycolysis as well as angiogenesis. Rescue experiment confirmed that glycolysis inhibitor 2-DG could offset the promoting effects of MEX3A on the proliferation, angiogenesis and glycolysis of CRC cells. In conclusion, MEX3A could facilitate CRC angiogenesis by activating the glycolytic pathway, suggesting that MEX3A may be a novel therapeutic target for CRC.

The Role of Targeted Therapy in the Multi-Disciplinary Approach to Colorectal Liver Metastasis

Colorectal cancer (CRC) is the second most common cause of cancer-related mortality in the United States. Among newly diagnosed patients with CRC, 20% will present with metastatic disease and another 25% will develop metastases. The surgical resection of the primary tumor and metastatic disease sites confers the best chance at long-term survival. Unfortunately, many patients will recur after resection or present with unresectable disease. As such, metastatic CRC is commonly treated with a combination of surgery, systemic therapy, and/or liver-directed therapies. Despite best efforts, 5-year survival for unresectable metastatic CRC is only about 20%. CRC is a heterogeneous disease and the underlying genetic differences inform behavior, treatment strategy, and prognosis. Given the limitations of cytotoxic chemotherapy and the growing role of molecular profiling, research has focused on identifying and developing targeted therapies. We herein review how genetic profiling informs prognosis, crucial cell-signaling pathways that play a role in CRC carcinogenesis, and currently approved targeted therapies for metastatic CRC.

The role of Nrf2 in the pathogenesis and treatment of ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease involving mainly the colorectal mucosa and submucosa, the incidence of which has been on the rise in recent years. Nuclear factor erythroid 2-related factor 2 (Nrf2), known for its key function as a transcription factor, is pivotal in inducing antioxidant stress and regulating inflammatory responses. Numerous investigations have demonstrated the involvement of the Nrf2 pathway in maintaining the development and normal function of the intestine, the development of UC, and UC-related intestinal fibrosis and carcinogenesis; meanwhile, therapeutic agents targeting the Nrf2 pathway have been widely investigated. This paper reviews the research progress of the Nrf2 signaling pathway in UC.

Molecular mechanisms targeting drug-resistance and metastasis in colorectal cancer: Updates and beyond

Colorectal cancer (CRC) is the third most diagnosed malignancy and a major leading cause of cancer-related deaths worldwide. Despite advances in therapeutic regimens, the number of patients presenting with metastatic CRC (mCRC) is increasing due to resistance to therapy, conferred by a small population of cancer cells, known as cancer stem cells. Targeted therapies have been highly successful in prolonging the overall survival of patients with mCRC. Agents are being developed to target key molecules involved in drug-resistance and metastasis of CRC, and these include vascular endothelial growth factor, epidermal growth factor receptor, human epidermal growth factor receptor-2, mitogen-activated extracellular signal-regulated kinase, in addition to immune checkpoints. Currently, there are several ongoing clinical trials of newly developed targeted agents, which have shown considerable clinical efficacy and have improved the prognosis of patients who do not benefit from conventional chemotherapy. In this review, we highlight recent developments in the use of existing and novel targeted agents against drug-resistant CRC and mCRC. Furthermore, we discuss limitations and challenges associated with targeted therapy and strategies to combat intrinsic and acquired resistance to these therapies, in addition to the importance of implementing better preclinical models and the application of personalized therapy based on predictive biomarkers for treatment selection.

Development of a risk model based on immune genes in patients with colon adenocarcinoma

BACKGROUND

The rapidly increasing morbidity and the poor prognosis making the colon adenocarcinoma not only common but also highly malignant. On the other hand, immunotherapy emerges as a therapeutic modality of colon cancer recently. In this study, we developed a prognostic risk model that is based on immune genes, which could predict the overall survival (OS) of patients with colon adenocarcinoma.

METHODS

The Cancer Genome Atlas (TCGA) database was used to download both transcriptomic and clinical data, and the ImmPort database was used to obtain immune genes. The least absolute shrinkage and selection operator (LASSO)-Cox regression was adopted to further select the key genes with prognostic value. Then the key genes were inputted into stepwise regression to calculated each patient's immune-related risk score (immune score). Survival, survminer packages and bilateral tests in R language were adopted to determine the optimal cut-off value (cut-off value) for the risk score. This threshold divides patients into immune-score high-risk and low-risk groups. The differences in the levels of infiltrating immune cells and stromal cells in the high and low immune risk groups were then calculated and compared by the CIBERSORT algorithm.

RESULTS

According to our results, a prognostic risk model was constructed based upon 26 immune-related genes. High immune score was shown to be a poor prognostic factor for colon adenocarcinoma patients, such as overall survival, progress free survival for different therapies, and tumor stages. High immune score was also associated with the abundance of CD4+ T cells and CD8+ T cells. In addition, the high immune score group, the expression levels of LMTK3, LAG3 and PD-L1 were higher than those in the low score group.

CONCLUSION

We developed a 26-immune gene model of colon adenocarcinoma to predict patient's survival. This model might be used in clinical practice as a prognostic instrument for patients diagnosed with colon adenocarcinoma.

Novel hKDR mouse model depicts the antiangiogenesis and apoptosis-promoting effects of neutralizing antibodies targeting vascular endothelial growth factor receptor 2

Vascular endothelial growth factor receptor 2 (VEGFR2)/KDR plays a critical role in tumor growth, diffusion, and invasion. The amino acid sequence homology of KDR between mouse and human in the VEGF ligand-binding domain was low, thus the WT mice could not be used to evaluate Abs against human KDR, and the lack of a suitable mouse model hindered both basic research and drug developments. Using the CRISPR/Cas9 technique, we successfully inserted different fragments of the human KDR coding sequence into the chromosomal mouse Kdr exon 4 locus to obtain an hKDR humanized mouse that can be used to evaluate the marketed Ab ramucirumab. In addition, the humanized mAb VEGFR-HK19 was developed, and a series of comparative assays with ramucirumab as the benchmark revealed that VEGFR-HK19 has higher affinity and superior antiproliferation activity. Moreover, VEGFR-HK19 selectively inhibited tumor growth in the hKDR mouse model but not in WT mice. The most important binding epitopes of VEGFR2-HK19 are D257, L313, and T315, located in the VEGF binding region. Therefore, the VEGFR2-HK19 Ab inhibits tumor growth by blocking VEGF-induced angiogenesis, inflammation, and promoting apoptosis. To our best knowledge, this novel humanized KDR mouse fills the gaps both in an animal model and the suitable in vivo evaluation method for developing antiangiogenesis therapies in the future, and the newly established humanized Ab is expected to be a drug candidate possibly benefitting tumor patients.

Tumor-Associated Neutrophils in Colorectal Cancer Development, Progression and Immunotherapy

The colorectal-cancer (CRC) incidence rate and mortality have remained high for several years. In recent years, immune-checkpoint-inhibitor (ICI) therapy has rapidly developed. However, it is only effective in a few CRC patients with microsatellite-instability-high (MSI-H) or mismatch-repair-deficient (dMMR) CRC. How to improve the efficiency of ICI therapy in CRC patients with microsatellite stability (MSS) remains a huge obstacle. Tumor-associated neutrophils (TANs), which are similar to macrophages, also have N1 and N2 phenotypes. They can be recruited and polarized through different cytokines or chemokines, and then play an antitumor or tumor-promoting role. In CRC, we find that the prognostic significance of TANs is still controversial. In this review, we describe the antitumor regulation of TANs, and their mechanism of promoting tumor progression by boosting the transformation of inflammation into tumors, facilitating tumor-cell proliferation, metastasis and angiogenesis. The targeting of TANs combined with ICIs may be a new treatment model for CRC. Relevant animal experiments have shown good responses, and clinical trials have also been carried out in succession. TANs, as “assistants” of ICI treatment, may become the key to the success of CRC immunotherapy, although no significant results have been obtained.

Neuropeptide Y, a paracrine factor secreted by cancer cells, is an independent regulator of angiogenesis in colon cancer

BACKGROUND

Resistance to anti-angiogenic therapies targeting vascular endothelial growth factor-A (VEGF-A) stems from VEGF-A independent angiogenesis mediated by other proangiogenic factors. Therefore identifying these factors in colon adenocarcinoma (CA) will reveal new therapeutic targets.

METHODS

Neuropeptide Y (NPY) and Y2 receptor (Y2R) expressions in CA were studied by immunohistochemical analysis. Orthotopic HT29 with intact VEGF-A gene and VEGF-A knockdown (by CRISPR/Cas9 gene-editing technique) HT29 colon cancer-bearing mice were treated with specific Y2R antagonists, and the effects on angiogenesis and tumour growth were studied. The direct effect of NPY on angiogenesis and the underlying molecular mechanism was elucidated by the modulation of Y2R receptors expressed on colonic endothelial cells (CEC).

RESULTS

The results demonstrated that NPY and Y2R are overexpressed in human CA, orthotopic HT29, and most interestingly in VEGF-A-depleted orthotopic HT29 tumours. Treatment with Y2R antagonists inhibited angiogenesis and thereby HT29 tumour growth. Blocking /silencing Y2R abrogated NPY-induced angiogenic potential of CEC. Mechanistically, NPY regulated the activation of the ERK/MAPK signalling pathway in CEC.

CONCLUSIONS

NPY derived from cancer cells independently regulates angiogenesis in CA by acting through Y2R present on CEC. Targeting NPY/Y2R thus emerges as a novel potential therapeutic strategy in CA.

Discovery of Oral Anticancer 1,2-Bis(hydroxymethyl)benzo[g]pyrrolo[2,1-a]phthalazine Hybrids That Inhibit Angiogenesis and Induce DNA Cross-Links

Designing hybrid molecules with dual functions is one approach to improve the therapeutic efficacy of combination treatment. We have previously conjugated phthalazine and bis(hydroxymethyl)pyrrole pharmacophores to form hybrids bearing antiangiogenesis and DNA interstrand cross-linking activities. To improve the bioavailability, we adopted a benzology approach to design and synthesize a new series of 1,2-bis(hydroxymethyl)benzo[g]pyrrolo[2,1-a]phthalazines. These new hybrids retained the dual functions and could be formulated into vehicles for intravenous and oral administration. Among them, we demonstrated that compound 19a with dimethylamine at the C6 position markedly suppressed the tumor growth of human small cell lung cancer cell line H526, squamous lung cancer cell line H520, and renal cancer cell line 786-O in nude mice, implying that compound 19a is a broad-spectrum anticancer agent. Our results implicated that the conjugation of antiangiogenic and DNA cross-linking is likely to be a helpful approach to improving the efficacy of combination therapy.

Combined Treatment with Acalabrutinib and Rapamycin Inhibits Glioma Stem Cells and Promotes Vascular Normalization by Downregulating BTK/mTOR/VEGF Signaling

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults, with a median duration of survival of approximately 14 months after diagnosis. High resistance to chemotherapy remains a major problem. Previously, BTK has been shown to be involved in the intracellular signal transduction including Akt/mTOR signaling and be critical for tumorigenesis. Thus, we aim to evaluate the effect of BTK and mTOR inhibition in GBM. We evaluated the viability of GBM cell lines after treatment with acalabrutinib and/or rapamycin through a SRB staining assay. We then evaluated the effect of both drugs on GBM stem cell-like phenotypes through various in vitro assay. Furthermore, we incubated HUVEC cells with tumorsphere conditioned media and observed their angiogenesis potential, with or without treatment. Finally, we conducted an in vivo study to confirm our in vitro findings and analyzed the effect of this combination on xenograft mice models. Drug combination assay demonstrated a synergistic relationship between acalabrutinib and rapamycin. CSCs phenotypes, including tumorsphere and colony formation with the associated expression of markers of pluripotency are inhibited by either acalabrutinib or rapamycin singly and these effects are enhanced upon combining acalabrutinib and rapamycin. We showed that the angiogenesis capabilities of HUVEC cells are significantly reduced after treatment with acalabrutinib and/or rapamycin. Xenograft tumors treated with both drugs showed significant volume reduction with minimal toxicity. Samples taken from the combined treatment group demonstrated an increased Desmin/CD31 and col IV/vessel ratio, suggesting an increased rate of vascular normalization. Our results demonstrate that BTK-mTOR inhibition disrupts the population of GBM-CSCs and contributes to normalizing GBM vascularization and thus, may serve as a basis for developing therapeutic strategies for chemoresistant/radioresistant GBM.

Immune-Checkpoint Inhibitors for Metastatic Colorectal Cancer: A Systematic Review of Clinical Outcomes

Simple Summary

In 2018, colorectal cancer (CRC) was declared the fourth most deadly cancer worldwide. Unfortunately, a quarter of all patients are diagnosed at late stages, when curative surgery is not possible, rendering systemic therapy and/or best supportive care as the only options. To our knowledge, this is the first systematic review assessing response and survival rates in patients with mCRC treated with immune-checkpoint inhibitors (ICIs). Our study established that ICIs show potentially superior response rates in mCRC patients, though only in those with high microsatellite instability (MSI). Nivolumab + regorafenib was reported to provide encouraging response in low-MSI (MSI-L) patients; however, additional studies using cohort randomization are required. Further studies are required, particularly regarding the mechanism of resistance to ICIs in MSI-L patients.

Abstract

Background. Colorectal cancer (CRC) is the fourth most deadly cancer worldwide. Unfortunately, a quarter of the patients are diagnosed at late stages, when surgical options are limited. Targeted therapies, particularly immune-checkpoint inhibitors (ICIs), are the latest addition and have been studied herein regarding their efficacy outcomes. Methods. Clinical studies were identified through the PubMed, Scopus and Cochrane databases. Any trial that evaluated ICIs in patients with metastatic CRC (mCRC) and reported the objective response rate was deemed eligible. Data analysis was performed by employing the random-effects model in STATA v.17. Results. A total of 461 articles were identified; 13 clinical trials were included, encompassing a total cohort of 1209 patients. Our study determined that a single PD-1/PD-L1 checkpoint blockade provides durable clinical response in mCRC patients with high microsatellite instability (MSI-H). The combinatorial therapy of CTLA-4 + PD-1 inhibitors also showed high response rates in pre-treated MSI-H patients. The single-arm REGONIVO trial reported durable clinical response in patients with microsatellite stable (MSS) status. Conclusions. Our study surmises that PD-1/PD-L1 inhibitors as well as combination therapy with CTLA-4 and PD-1 inhibitors show encouraging response rates in mCRC patients, albeit exclusively in patients with cancer that are of MSI-H status. A single study suggests that nivolumab + regorafenib can reach a durable response rate in MSS patients; however, further studies in larger randomized settings are required.

Colorectal Cancer: From Genetic Landscape to Targeted Therapy

Colorectal cancer (CRC) is the third most common cancer type and the second cause of death worldwide. The advancement in understanding molecular pathways involved in CRC has led to new classifications based on the molecular characteristics of each tumor and also improved CRC management through the integration of targeted therapy into clinical practice. In this review, we will present the main molecular pathways involved in CRC carcinogenesis, the molecular classifications. The anti-VEGF and anti-EGFR therapies currently used in CRC treatment and those under clinical investigation will also be outlined, as well as the mechanisms of primary and acquired resistance to anti-EGFR monoclonal antibodies (cetuximab and panitumumab). Targeted therapy has led to great improvement in the treatment of metastatic CRC. However, there has been variability in CRC treatment outcomes due to molecular heterogeneity in colorectal tumors, which underscores the need for identifying prognostic and predictive biomarkers for CRC-targeted drugs.

Dissecting the Hormonal Signaling Landscape in Castration-Resistant Prostate Cancer

Understanding the molecular mechanisms underlying prostate cancer (PCa) progression towards its most aggressive, castration-resistant (CRPC) stage is urgently needed to improve the therapeutic options for this almost incurable pathology. Interestingly, CRPC is known to be characterized by a peculiar hormonal landscape. It is now well established that the androgen/androgen receptor (AR) axis is still active in CRPC cells. The persistent activity of this axis in PCa progression has been shown to be related to different mechanisms, such as intratumoral androgen synthesis, AR amplification and mutations, AR mRNA alternative splicing, increased expression/activity of AR-related transcription factors and coregulators. The hypothalamic gonadotropin-releasing hormone (GnRH), by binding to its specific receptors (GnRH-Rs) at the pituitary level, plays a pivotal role in the regulation of the reproductive functions. GnRH and GnRH-R are also expressed in different types of tumors, including PCa. Specifically, it has been demonstrated that, in CRPC cells, the activation of GnRH-Rs is associated with a significant antiproliferative/proapoptotic, antimetastatic and antiangiogenic activity. This antitumor activity is mainly mediated by the GnRH-R-associated Gαi/cAMP signaling pathway. In this review, we dissect the molecular mechanisms underlying the role of the androgen/AR and GnRH/GnRH-R axes in CRPC progression and the possible therapeutic implications.

Targeting thymidine phosphorylase inhibition in human colorectal cancer xenografts

Human thymidine phosphorylase (hTP) is overexpressed in several solid tumors and is commonly associated with aggressiveness and unfavorable prognosis. 6-(((1,3-Dihydroxypropan-2-yl)amino)methyl)-5-iodopyrimidine-2,4(1H,3H)-dione (CPBMF-223) is a noncompetitive hTP inhibitor, which has been described as a tumor angiogenesis inhibitor. The present study investigated the effects of CPBMF-223 in a xenograft tumor induced by human colorectal carcinoma cells (HCT-116). Additionally, CPBMF-223 capacity to reduce cell migration, its toxicological profile, and pharmacokinetic characteristics, were also evaluated. The intraperitoneal treatment with CPBMF-223 markedly prevented the relative tumor growth with an efficacy similar to that observed for 5-fluorouracil. Interestingly, number of vessels were significantly decreased in the treated groups. Moreover, CPBMF-223 significantly reduced the migration of cell line HCT-116. In the Ames assay and in an acute oral toxicity test, the molecule did not alter any evaluated parameter. Using the zebrafish toxicity model, cardiac and locomotor parameters were slightly changed. Regarding the pharmacokinetics profile, CPBMF-223 showed clearance of 9.42 L/h/kg after intravenous administration, oral bioavailability of 13.5%, and a half-life of 0.75 h. Our findings shed new light on the role of hTP in colorectal cancer induced by HCT-116 cell in mice, pointing out CPBMF-223 as, hopefully, a promising drug candidate.

Different Forms of Tumor Vascularization and Their Clinical Implications Focusing on Vessel Co-option in Colorectal Cancer Liver Metastases

In modern anti-cancer therapy of metastatic colorectal cancer (mCRC) the anti-angiogenic treatment targeting sprouting angiogenesis is firmly established for more than a decade. However, its clinical benefits still remain limited. As liver metastases (LM) represent the most common metastatic site of colorectal cancer and affect approximately one-quarter of the patients diagnosed with this malignancy, its treatment is an essential aspect for patients' prognosis. Especially in the perioperative setting, the application of anti-angiogenic drugs represents a therapeutic option that may be used in case of high-risk or borderline resectable colorectal cancer liver metastases (CRCLM) in order to achieve secondary resectability. Regarding CRCLM, one reason for the limitations of anti-angiogenic treatment may be represented by vessel co-option (VCO), which is an alternative mechanism of blood supply that differs fundamentally from the well-known sprouting angiogenesis and occurs in a significant fraction of CRCLM. In this scenario, tumor cells hijack pre-existing mature vessels of the host organ independently from stimulating new vessels formation. This represents an escape mechanism from common anti-angiogenic anti-cancer treatments, as they primarily target the main trigger of sprouting angiogenesis, the vascular endothelial growth factor A. Moreover, the mechanism of blood supply in CRCLM can be deduced from their phenotypic histopathological growth pattern (HGP). For that, a specific guideline has already been implemented. These HGP vary not only regarding their blood supply, but also concerning their tumor microenvironment (TME), as notable differences in immune cell infiltration and desmoplastic reaction surrounding the CRCLM can be observed. The latter actually serves as one of the central criteria for the classification of the HGP. Regarding the clinically relevant effects of the HGP, it is still a topic of research whether the VCO-subgroup of CRCLM results in an impaired treatment response to anti-angiogenic treatment when compared to an angiogenic subgroup. However, it is well-proved, that VCO in CRCLM generally relates to an inferior survival compared to the angiogenic subgroup. Altogether the different types of blood supply result in a relevant influence on the patients' prognosis. This reinforces the need of an extended understanding of the underlying mechanisms of VCO in CRCLM with the aim to generate more comprehensive approaches which can target tumor vessels alternatively or even other components of the TME. This review aims to augment the current state of knowledge on VCO in CRCLM and other tumor entities and its impact on anti-angiogenic anti-cancer therapy.

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.

The tumorigenic and therapeutic functions of exosomes in colorectal cancer: Opportunity and challenges

Most cells release extracellular vesicles (EVs) mediating intercellular communication via transferring various biomolecules including proteins, nucleic acids, and lipids. A subset of EVs is exosomes that promote tumorigenesis. Different tumour cells such as colorectal cancer (CRC) cells produce exosomes that participate in the progression of CRC. Exosomes cargo including proteins and miRNAs not only support proliferation and metastasis of tumour cells but also mediate chemoresistance, immunomodulation and angiogenesis. In addition, as exosomes are present in most body fluids, they can hold the great capacity for clinical usage in early diagnosis and prognosis of CRC. Exosomes from CRC (CRC-Exo) differentially contain proteins and miRNAs that make them a promising candidate for CRC diagnosis by a simple liquid-biopsy. Despite hopeful results, some challanges about exosomes terminology and definition remains to be clarified in further experiments. In addition, there are little clinical trials regarding the application of exosomes in CRC treatment, therefore additional studies are essential focusing on exosome biology and translation of preclinical findings into the clinic. The present study discusses the key role of exosomes in CRC progression and diagnosis. Furthermore, it describes the opportunity and challenges associated with using exosomes as tumour markers.

Chemosensitization of HT29 and HT29-5FU Cell Lines by a Combination of a Multi-Tyrosine Kinase Inhibitor and 5FU Downregulates ABCC1 and Inhibits PIK3CA in Light of Their Importance in Saudi Colorectal Cancer

Colorectal cancer (CRC) remains one of the main causes of death worldwide and in Saudi Arabia. The toxicity and the development of resistance against 5 fluorouracil 5FU pose increasing therapeutic difficulties, which necessitates the development of personalized drugs and drug combinations. Objectives: First, to determine the most important kinases and kinase pathways, and the amount of ABC transporters and KRAS in samples taken from Saudi CRC patients. Second, to investigate the chemosensitizing effect of LY294002 and HAA₂₀₂₀ and their combinations with 5FU on HT29, HT29-5FU, HCT116, and HCT116-5FU CRC cells, their effect on the three ABC transporters, cell cycle, and apoptosis, in light of the important kinase pathways resulting from the first part of this study. Methods: The PamChip^® peptide micro-array profiling was used to determine the level of kinase and targets in the Saudi CRC samples. Next, RT-PCR, MTT cytotoxicity, Western blotting, perturbation of cell cycle, annexin V, and immunofluorescence assays were used to investigate the effect on CRC, MRC5, and HUVEC cells. Results: The kinase activity profiling highlighted the importance of the PI3K/AKT, MAPK, and the growth factors pathways in the Saudi CRC samples. PIK3CA was the most overexpressed, and it was associated with increased level of mutated KRAS and the three ABC transporters, especially ABCC1 in the Saudi samples. Next, combining HAA₂₀₂₀ with 5FU exhibited the best synergistic and resistance-reversal effect in the four CRC cells, and the highest selectivity indices compared to MRC5 and HUVEC normal cells. Additionally, HAA₂₀₂₀ with 5FU exerted significant inhibition of ABCC1 in the four CRC cells, and inhibition of PIK3CA/AKT/MAPK7/ERK in HT29 and HT29-5FU cells. The combination also inhibited EGFR, increased the preG₁/S cell cycle phases, apoptosis, and caspase 8 in HT29 cells, while it increased the G₁ phase, p21/p27, and apoptosis in HT29-5FU cells. Conclusion: We have combined the PamChip kinase profiling of Saudi CRC samples with in vitro drug combination studies in four CRC cells, highlighting the importance of targeting PIK3CA and ABCC1 for Saudi CRC patients, especially given that the overexpression of PIK3CA mutations was previously linked with the lack of activity for the anti-EGFRs as first line treatment for CRC patients. The combination of HAA₂₀₂₀ and 5FU has selectively sensitized the four CRC cells to 5FU and could be further studied.

Molecular Mechanisms of Colon Cancer Progression and Metastasis: Recent Insights and Advancements

Colorectal cancer (CRC), the third most common type of cancer, is the second leading cause of cancer-related mortality rates worldwide. Although modern research was able to shed light on the pathogenesis of CRC and provide enhanced screening strategies, the prevalence of CRC is still on the rise. Studies showed several cellular signaling pathways dysregulated in CRC, leading to the onset of malignant phenotypes. Therefore, analyzing signaling pathways involved in CRC metastasis is necessary to elucidate the underlying mechanism of CRC progression and pharmacotherapy. This review focused on target genes as well as various cellular signaling pathways including Wnt/β-catenin, p53, TGF-β/SMAD, NF-κB, Notch, VEGF, and JAKs/STAT3, which are associated with CRC progression and metastasis. Additionally, alternations in methylation patterns in relation with signaling pathways involved in regulating various cellular mechanisms such as cell cycle, transcription, apoptosis, and angiogenesis as well as invasion and metastasis were also reviewed. To date, understanding the genomic and epigenomic instability has identified candidate biomarkers that are validated for routine clinical use in CRC management. Nevertheless, better understanding of the onset and progression of CRC can aid in the development of early detection molecular markers and risk stratification methods to improve the clinical care of CRC patients.

Vascular co-option and vasculogenic mimicry mediate resistance to antiangiogenic strategies

BACKGROUND

The concept that all the tumors need the formation of new vessels to grow inspired the hypothesis that inhibition of angiogenesis would have led to "cure" cancer. The expectancy that this type of therapy would have avoided the insurgence of resistance was based on the concept that targeting normal vessels, instead of the cancer cells which easily develop new mutations, would have allowed evasion of drug caused selection is, however, more complex as it was made apparent by the discovery of nonangiogenic tumors. At the same time an increasing number of trials with antiangiogenic drugs were coming out as not as successful as expected, mostly because of the appearance of unexpected resistance.

RECENT FINDINGS

Among the several different mechanisms of resistance to antiangiogenic treatment by now described, we review the evidences that vascular co-option and vasculogenic mimicry by nonangiogenic tumors are effectively two of such mechanisms. We focused on reviewing exclusively the study, both clinical and preclinical, that offer a demonstration that vascular co-option and vasculogenic mimicry are effectively two mechanisms of both intrinsic and acquired resistance.

CONCLUSION

The discovery that vascular co-opting and vasculogenic mimicry are two ways of escaping antiangiogenic treatment, prompts the need for a better understanding of this phenomenon in order to improve cancer treatment.

Exosomes in Angiogenesis and Anti-angiogenic Therapy in Cancers

Angiogenesis is the process through which new blood vessels are formed from pre-existing ones. Exosomes are involved in angiogenesis in cancer progression by transporting numerous pro-angiogenic biomolecules like vascular endothelial growth factor (VEGF), matrix metalloproteinases (MMPs), and microRNAs. Exosomes promote angiogenesis by suppressing expression of factor-inhibiting hypoxia-inducible factor 1 (HIF-1). Uptake of tumor-derived exosomes (TEX) by normal endothelial cells activates angiogenic signaling pathways in endothelial cells and stimulates new vessel formation. TEX-driven cross-talk of mesenchymal stem cells (MSCs) with immune cells blocks their anti-tumor activity. Effective inhibition of tumor angiogenesis may arrest tumor progression. Bevacizumab, a VEGF-specific antibody, was the first antiangiogenic agent to enter the clinic. The most important clinical problem associated with cancer therapy using VEGF- or VEFGR-targeting agents is drug resistance. Combined strategies based on angiogenesis inhibitors and immunotherapy effectively enhances therapies in various cancers, but effective treatment requires further research.

Identification of novel potent and non-toxic anticancer, anti-angiogenic and antimetastatic rhenium complexes against colorectal carcinoma

Combination therapy targeting both tumor growth and vascularization is considered to be a cornerstone for colorectal carcinomas (CRC) treatment. However, the major obstacles of most clinical anticancer drugs are their weak selective activity towards cancer cells and inherent inner organs toxicity, accompanied with fast drug resistance development. In our effort to discover novel selective and non-toxic agents effective against CRC, we designed, synthesized and characterized a series of rhenium(I) tricarbonyl-based complexes with increased lipophilicity. Two of these novel compounds were discovered to possess remarkable anticancer, anti-angiogenic and antimetastatic activity in vivo (zebrafish-human HCT-116 xenograft model), being effective at very low doses (1-3 μM). At doses as high as 250 μM the complexes did not provoke toxicity issues encountered in clinical anticancer drugs (cardio-, hepato-, and myelotoxicity). In vivo assays showed that the two compounds exceed the anti-tumor and anti-angiogenic activity of clinical drugs cisplatin and sunitinib malate, and display a large therapeutic window.

Efficacy and safety of ramucirumab treatment in patients with advanced colorectal cancer: A protocol for systematic review and meta analysis

BACKGROUND

vascular endothelial growth factor receptor 2 (VEGFR-2) has an important role in colorectal cancer pathogenesis and progression. The aim of our study is to provide a protocol for assessing the efficacy and safety of ramucirumab (a monoclonal antibody VEGFR-2 antagonist) for the treatment of advanced colorectal cancer.

METHODS

The systematic review will be reported according to the preferred reporting items for systematic reviews and meta-analyses protocols. Relevant randomized controlled trials were searched from PubMed, Cochrane Library, Web of Science, Excerpt Medica Database, China National Knowledge Infrastructure, and Wanfang Database. Papers in English or Chinese published from their inception to February 2020 will be included without any restrictions.Study selection and data extraction will be performed independently by 2 investigators. The clinical outcomes including overall response rate, complete response rate (disease control rate), overall survival, progression-free survival, quality of life, immune function, and adverse events, were systematically evaluated. Review Manager 5.3 and Stata 14.0 were used for data analysis, and a fixed or random-effect model of meta-analysis will be used depending upon the heterogeneity observed between studies. Subgroup analysis will be carried out depending on the availability of sufficient clinical data.

RESULTS AND CONCLUSION

The findings of this systematic review and meta-analysis will be published in a peer-reviewed journal, and provide more evidence-based guidance in clinical practice.

PROSPERO REGISTRATION NUMBER

CRD42020165683.

Comprehensive review of targeted therapy for colorectal cancer

Colorectal cancer (CRC) is among the most lethal and prevalent malignancies in the world and was responsible for nearly 881,000 cancer-related deaths in 2018. Surgery and chemotherapy have long been the first choices for cancer patients. However, the prognosis of CRC has never been satisfying, especially for patients with metastatic lesions. Targeted therapy is a new optional approach that has successfully prolonged overall survival for CRC patients. Following successes with the anti-EGFR (epidermal growth factor receptor) agent cetuximab and the anti-angiogenesis agent bevacizumab, new agents blocking different critical pathways as well as immune checkpoints are emerging at an unprecedented rate. Guidelines worldwide are currently updating the recommended targeted drugs on the basis of the increasing number of high-quality clinical trials. This review provides an overview of existing CRC-targeted agents and their underlying mechanisms, as well as a discussion of their limitations and future trends.

Liposomal simvastatin sensitizes C26 murine colon carcinoma to the antitumor effects of liposomal 5-fluorouracil in vivo

5-Fluorouracil-based therapy remains the main approach in colorectal cancer, even though there are still some drawbacks, such as chemoresistance. In this study we combined 5-fluorouracil encapsulated in long-circulating liposomes with simvastatin, also encapsulated in long-circulating liposomes, that was previously proved to exert antitumor actions on the same tumor model. The production of angiogenic/inflammatory proteins was assessed by protein array and the production of markers for tumor aggressiveness (Bcl-2, Bax, and nuclear factor [NF]-κB) were determined by western blot analysis. Intratumor oxidative stress was evaluated through measurement of malondialdehyde level by HPLC, and through spectrophotometric analysis of catalytic activity of catalase and of total antioxidant capacity. Immunohistochemical analysis of tumors for CD31 expression was assessed. Intratumor activity of MMP-2 by gelatin zymography was also carried out. Our results revealed that combined therapies based on liposomal formulations exerted enhanced antitumor activities compared with combined treatment with free drugs. Sequential treatment with liposomal simvastatin and liposomal 5-fluorouracil showed the strongest antitumor activity in C26 colon carcinoma in vivo, mainly through inhibition of tumor angiogenesis. Important markers for cancer progression (Bcl-2, Bax, NF-κB, and intratumor antioxidants) showed that liposomal simvastatin might sensitize C26 cells to liposomal 5-fluorouracil treatment in both regimens tested. The outcome of simultaneous treatment with liposomal formulations was superior to sequential treatment with both liposomal types as the invasive capacity of C26 tumors was strongly increased after the latest treatment. The antitumor efficacy of combined therapy in C26 colon carcinoma might be linked to the restorative effects on proteins balance involved in tumor angiogenesis.

Novel human Ab against vascular endothelial growth factor receptor 2 shows therapeutic potential for leukemia and prostate cancer

Vascular endothelial growth factor receptor 2 (VEGFR2) is highly expressed in tumor‐associated endothelial cells, where it modulates tumor‐promoting angiogenesis, and it is also found on the surface of tumor cells. Currently, there are no Ab therapeutics targeting VEGFR2 approved for the treatment of prostate cancer or leukemia. Therefore, development of novel efficacious anti‐VEGFR2 Abs will benefit cancer patients. We used the Institute of Cellular and Organismic Biology human Ab library and affinity maturation to develop a fully human Ab, anti‐VEGFR2‐AF, which shows excellent VEGFR2 binding activity. Anti‐VEGFR2‐AF bound Ig‐like domain 3 of VEGFR2 extracellular region to disrupt the interaction between VEGF‐A and VEGFR2, neutralizing downstream signaling of the receptor. Moreover, anti‐VEGFR2‐AF inhibited capillary structure formation and exerted Ab‐dependent cell‐mediated cytotoxicity and complement‐dependent cytotoxicity in vitro. We found that VEGFR2 is expressed in PC‐3 human prostate cancer cell line and associated with malignancy and metastasis of human prostate cancer. In a PC‐3 xenograft mouse model, treatment with anti‐VEGFR2‐AF repressed tumor growth and angiogenesis as effectively and safely as US FDA‐approved anti‐VEGFR2 therapeutic, ramucirumab. We also report for the first time that addition of anti‐VEGFR2 Ab can enhance the efficacy of docetaxel in the treatment of a prostate cancer mouse model. In HL‐60 human leukemia‐xenografted mice, anti‐VEGFR2‐AF showed better efficacy than ramucirumab with prolonged survival and reduced metastasis of leukemia cells to ovaries and lymph nodes. Our findings suggest that anti‐VEGFR2‐AF has strong potential as a cancer therapy that could directly target VEGFR2‐expressing tumor cells in addition to its anti‐angiogenic action.

Mechanisms of resistance to anti-angiogenic treatments

Hailed as the cancer treatment to end all the resistance to treatment, anti-angiogenic therapy turned out to be not quite what was promised. The hope that this therapeutic approach would not have suffered by the phenomenon of resistance was based on the fact that was targeting normal vessels rather than tumour cells prone to mutation and subject to drug induced selection. However, reality turned out to be more complex and since 1997, several mechanisms of resistance have been described to the point that the study of resistance to these drugs is now a very large field. Far from being exhaustive, this paper presents the main mechanisms discovered trough some examples.

Inhibition of vascular endothelial growth factor in young adult mice causes low bone blood flow and bone strength with no effect on bone mass in trabecular regions

OBJECTIVE

To determine the effect of an antibody to vascular endothelial growth factor (VEGF) on bone blood flow, bone strength, and bone mass in the young adult mouse.

METHODS

Ten-week-old male BALB/cJ mice were body weight-randomized into either a rodent anti-VEGF monoclonal antibody (anti-VEGF, B20-4.1.1; 5 mg/kg 2×/wk.; n = 12) group or a vehicle (VEH; n = 12) group. After 42 days, mice were evaluated for bone blood flow at the distal femur by 18F-NaF-PET/CT and then necropsied. Samples from trabecular and cortical bone regions were evaluated for bone strength by mechanical testing, bone mass by peripheral quantitative computed tomography (pQCT), and micoarchitecture (MicroCT). Hydration of the whole femur was studied by proton nuclear magnetic resonance relaxometry (1H NMR).

RESULTS

Distal femur blood flow was 43% lower in anti-VEGF mice than in VEH mice (p = 0.009). Ultimate load in the lumbar vertebral body was 25% lower in anti-VEGF than in VEH mice (p = 0.013). Bone mineral density (BMD) in the trabecular region of the proximal humeral metaphysis by pQCT, and bone volume fraction and volumetric BMD by MicroCT were the same in the two groups. Volume fraction of bound water (BW) of the whole femur was 14% lower in anti-VEGF than in VEH mice (p = 0.003). Finally, BW, but not cortical tissue mineral density, helped section modulus explain the variance in the ultimate moment experienced by the femur in three-point bending.

CONCLUSION

Anti-VEGF caused low bone blood flow and bone strength in trabecular bone regions without influencing BMD and microarchitecture. Low bone strength was also associated with low bone hydration. These data suggest that bone blood flow is a novel bone property that affects bone quality.

Quantitative proteomic profiling of tumor-associated vascular endothelial cells in colorectal cancer

To investigate the global proteomic profiles of vascular endothelial cells (VECs) in the tumor microenvironment and antiangiogenic therapy for colorectal cancer (CRC), matched pairs of normal (NVECs) and tumor-associated VECs (TVECs) were purified from CRC tissues by laser capture microdissection and subjected to iTRAQ-based quantitative proteomics analysis. Here, 216 differentially expressed proteins (DEPs) were identified and used for bioinformatics analysis. Interestingly, these proteins were implicated in epithelial mesenchymal transition (EMT), ECM-receptor interaction, focal adhesion, PI3K-Akt signaling pathway, angiogenesis and HIF-1 signaling pathway, which may play important roles in CRC angiogenesis. Among these DEPs we found that Tenascin-C (TNC) was upregulated in TVECs of CRC and correlated with CRC multistage carcinogenesis and metastasis. Furthermore, the reduction of tumor-derived TNC could attenuate human umbilical vein endothelial cell (HUVEC) proliferation, migration and tube formation through ITGB3/FAK/Akt signaling pathway. Based on the present work, we provided a large-scale proteomic profiling of VECs in CRC with quantitative information, a certain number of potential antiangiogenic targets and a novel vision in the angiogenesis bio-mechanism of CRC.

Summary: We provided large-scale proteomic profiling of vascular endothelial cells in colorectal cancer with quantitative information, a number of potential antiangiogenic targets and a novel vision in the angiogenesis bio-mechanism of CRC.

Efficacy and safety of trifluridine/tipiracil in third-line and beyond for the treatment of patients with metastatic colorectal cancer in routine clinical practice: patterns of use and prognostic nomogram

INTRODUCTION

Trifluridine/tipiracil combination has shown a benefit over placebo in the treatment of patients with chemorefractory metastatic colorectal cancer (mCRC). We evaluated the efficacy and safety of this combination in the real-life setting at eight Galician centers in Spain.

PATIENTS AND METHODS

This is a retrospective study of a cohort of patients with mCRC in treatment with trifluridine/tipiracil within usual clinical practice who have been previously treated or are not considered candidates for treatment with available therapies.

RESULTS

A total of 160 mCRC patients were included. Our data showed that 11.9% of patients achieved disease control. Median progression-free survival was 2.75 months; at 5.66 months follow-up, median overall survival was 7.94 months. Asthenia and neutropenia (48.1% both) were the most frequent adverse events. Overall survival was lower in patients with ECOG 2, multiple metastatic sites, platelets count 350,000/µl, alkaline phosphatase > 500 IU/l, and carcinoembryonic antigen > 10 ng/ml.

CONCLUSION

The results of this study confirm the efficacy and safety of trifluridine/tipiracil in chemorefractory mCRC patients. However, patients in clinical practice differ from patients in clinical trials. Due to this, prognostic factors have special importance to offer the best therapeutic approach.