VEGFR2 regulates endothelial differentiation of colon cancer cells

M2 macrophage-derived exosomes promote cell proliferation, migration and EMT of non-small cell lung cancer by secreting miR-155-5p

Tumor-associated macrophages (TAMs) are a type of highly plastic immune cells in the tumor microenvironment (TME), which can be classified into two main phenotypes: classical activated M1 macrophages and alternatively activated M2 macrophages. As previously reported, M2-polarized TAMs play critical role in promoting the progression of non-small cell lung cancer (NSCLC) via secreting exosomes, but the detailed mechanisms are still largely unknown. In the present study, the THP-1 monocytes were sequentially induced into M0 and M2-polarized macrophages, and the exosomes were obtained from M0 (M0-exos) and M2 (M2-exos) polarized macrophages, respectively, and co-cultured with NSCLC cells (H1299 and A549) to establish the exosomes-cell co-culture system in vitro. As it was determined by MTT assay, RT-qPCR and Transwell assay, in contrast with the M0-exos, M2-exos significantly promoted cell proliferation, migration and epithelial-mesenchymal transition (EMT) process in NSCLC cells. Next, through screening the contents in the exosomes, it was verified that miR-155-5p was especially enriched in the M2-exos, and M2-exos enhanced cancer aggressiveness and tumorigenesis in in vitro NSCLC cells and in vivo xenograft tumor-bearing mice models via delivering miR-155-5p. The detailed molecular mechanisms were subsequently elucidated, and it was found that miR-155-5p bound with HuR to increase the stability and expression levels of VEGFR2, which further activated the tumor-promoting PI3K/Akt/mTOR signal pathway, and M2-exos-enhanced cancer progression in NSCLC cells were apparently suppressed by downregulating VEGFR2 and PI3K inhibitor LY294002 co-treatment. Taken together, M2-polarized TAMs secreted miR-155-5p-containing exosomes to enhanced cancer aggressiveness of NSCLC by activating the VEGFR2/PI3K/Akt/mTOR pathway in a HuR-dependent manner.

Transient intracellular expression of PD-L1 and VEGFR2 bispecific nanobody in cancer cells inspires long-term T cell activation and infiltration to combat tumor and inhibit cancer metastasis

BACKGROUND

PD-L1, an immune checkpoint inhibitor, and VEGFR2, essential for cancer metastasis, play pivotal roles in tumorigenesis. However, their miniature bispecific intracellular nanobodies for combining check-point blockade and anti-metastasis anticancer therapy remain underexplored.

METHODS

The intrabodies were developed using gene cloning technology. Specificity of the intrabodies was testified using Western blot, co-immunoprecipitation (co-IP) analysis, antibody competitive binding assay, flow cytometry analysis, etc. Checkpoint blockade was demonstrated using antibody-antigen competitive binding assay. Cancer cell migration was determined using scratch assay. Combined anti-cancer therapeutic efficacy of FAP1V2 was determined in vivo of mice models. The PD-1hi immune cells, TCR βhi and CD25hi T-cells were analyzed by flow cytometry, and cancer cell metastasis was performed using immune-fluorescence analysis on lung and liver tissues. Transcriptome analysis was performed to explore signaling pathways associated with the enhanced anticancer efficiency.

RESULTS

Bispecific intrabody FAP1V2 fused with antibody VH regions, was successfully developed and verified with its ability to target and block human and mouse PD-L1 and VEGFR2, inhibiting cancer cell binding to PD-1 and reducing their migratory capacity. Compared to the other treatment, two-rounds of transient FAP1V2 expression in LLC cells in experimental mice models achieved remarkable tumor inhibition, which brought about complete immune inhibition on growth of secondary-round of LLC tumor in 1/6 of the tested mice, inspired long-term activation of TCR βhi T cells and increased their infiltration to tumors, inhibited the emergence of PD-1hi immune cells, indicating prevented T cell depletion. The elevated CD25 expression also supported the success in enhancing immune response reported by elevated T cell activity in spleen. Transcriptome analysis identified critical intracellular pathways regulated by the concurrent blockade of PD-L1 and VEGFR2.

CONCLUSION

PD-L1 and VEGFR2- bispecific VH intracellular nanobody was highly biocompatible and showed the potential for combined anti-cancer therapy through long-term immune activation mediated by PD-L1/PD-1 checkpoint blockade and anti-metastasis mediated by VEGFR2 blockade.

The Clinical Relevance of Epithelial-to-Mesenchymal Transition Hallmarks: A Cut-Off-Based Approach in Healthy and Cancerous Cell Lines

The atypical activation of the epithelial-to-mesenchymal transition represents one of the main mechanisms driving cancer cell dissemination. It enables epithelial cancer cells to detach from the primary tumor mass and gain survival advantages in the bloodstream, significantly contributing to the spread of circulating tumor cells. Notably, epithelial-to-mesenchymal transition is not a binary process but rather leads to the formation of a wide range of cell subpopulations characterized by the simultaneous expression of both epithelial and mesenchymal markers. Therefore, analyzing the modulation of EMT hallmarks during the conversion from healthy cells to metastatic cancer cells, which acquire stem mesenchymal characteristics, is of particular interest. This study investigates the expression of a panel of epithelial-to-mesenchymal transition-related genes in healthy cells, primary and metastatic cancer cells, and in mesenchymal cell lines, derived from various tissues, including the lung, colon, pancreas, skin, and neuro-ectoderm, with the aim of identifying potential cut-off values for assessing cancer aggressiveness. Interestingly, we found that the expression levels of CDH1, which encodes the epithelial marker E-cadherin, CDH5, encoding vascular endothelial cadherin, and the epithelial-to-mesenchymal transition-transcription factor ZEB1, effectively distinguished primary from metastatic cancer cells. Additionally, our data suggest a tissue-specific signature in the modulation of epithelial-to-mesenchymal transition markers during cancer progression. Overall, our results underscore the importance of investigating epithelial-to-mesenchymal transition as a tissue-specific process to identify the most suitable markers acting as potential indicators of disease aggressiveness and therapeutic responsiveness.

Compensatory lymphangiogenesis is required for edema resolution in zebrafish

Edema, characterized by the accumulation of interstitial fluid, poses significant challenges in various pathological conditions. Lymphangiogenesis is critical in edema clearance, and delayed or inadequate lymphatic responses significantly hinder healing processes. However, real-time observation of dynamic changes in lymphangiogenesis during tissue repair in animal models has been challenging, leaving the mechanisms behind compensatory lymphatic activation for edema clearance largely unexplored. To address this gap, we subjected zebrafish larvae to osmotic stress using hypertonic (375 mOsm/L) and isotonic (37.5 mOsm/L) solutions to induce osmotic imbalance and subsequent edema formation. Intravital imaging of vascular transgenic larvae revealed significant lymphatic vessel remodeling during tissue edema. The observed increase in lymphatic endothelial progenitor cells, alongside the sustained expansion and remodeling of primary lymphatics, indicates active lymphangiogenesis during the recovery phase. We developed a novel method employing translating ribosome affinity purification to analyze the translatome of lymphatic and venous endothelial cells in vivo, which uncovered the upregulation of key pro-lymphangiogenic genes, particularly vegfr2 and vegfr3, during tissue recovery. Inhibition of compensatory lymphangiogenesis impaired edema fluid clearance and tissue recovery. Our findings establish a new model for in vivo live imaging of compensatory lymphangiogenesis and provide a novel approach in investigating lymphatic activation during edema resolution.

New indolin-2-ones, possessing sunitinib scaffold as HDAC inhibitors and anti-cancer agents with potential VEGFR inhibition activity; design, synthesis and biological evaluation

New series of indolin-2-ones possessing sunitinib scaffold and a hydroxamic acid moiety were designed and synthesized as inhibitors of HDAC, demonstrating significant anti-cancer properties with potential VEGFR inhibition, using sunitinib and vorinostat as the lead compounds. The newly synthesized compounds incorporate the sunitinib framework along with functional groups derived from vorinostat, thus they can be named the rigid analogs of vorinostat. The cytotoxic effects of these compounds were assessed against two cancer cell lines, HCT116 (human colon cancer) and HT29 (human colon adenocarcinoma), as well as NIH (a normal fibroblast cell line). A majority of the compounds displayed notable cytotoxicity towards HT-29 and HCT-116, with IC50 values ranging from 1.78 to 38.54 µM notably, compound 13c exhibited the highest anti-proliferative effect against HT-29, with an IC50 of 1.78 µM, comparable to or exceeding that of the reference drugs, sunitinib and vorinostat. This compound reduced the expression levels of VEGFR-2 and phosphorylated VEGFR-2 (pVEGFR-2) by approximately 80 % and inhibited the HDAC1 enzyme (IC50 = 1.07 µM), indicating its anticancer activity through the targeting of these enzymes. Further cellular mechanism investigations revealed that compound 13c induced substantial apoptosis in HCT-116 cells, with a total apoptotic cell percentage of 41.1 % in treated cells (2.59 µM), compared to negative control (3.68 %)). The CAM assay also indicated that 13c possesses antiangiogenic property similar to that of sunitinib. Additionally, a molecular docking simulation supported the initial design strategy and suggested a common mode of interaction of compound 13c at the binding sites of VEGFR-2 and HDAC1. These findings suggested that 13c could be as a promising lead targeting VEGFR-2 and HDAC1. Therefore, it deserved further investigation for cancer treatment.

Probing structural requirements for thiazole-based mimetics of sunitinib as potent VEGFR-2 inhibitors

Novel thiazole analogs 3a, 3b, 4, 5, 6a-g, 8a, 8b, 9a-c, 10a-d and 11 were designed and synthesized as molecular mimetics of sunitinib. In vitro antitumor activity of the obtained compounds was investigated against HepG2, HCT-116, MCF-7, HeP-2 and HeLa cancer cell lines. The obtained data showed that compounds 3b and 10c are the most potent members toward HepG2, HCT-116, MCF-7 and HeLa cells. Moreover, compounds 3a, 3b, 6g, 8a and 10c were assessed for their in vitro VEGFR-2 inhibitory activity. Results proved that compound 10c exhibited outstanding VEGFR-2 inhibition (IC50 = 0.104 μM) compared to sunitinib. Compound 10c paused the G0-G1 phase of the cell cycle in HCT-116 and MCF-7 cells and the S phase in HeLa cells. Additionally, compound 10c elevated caspase-3/9 levels in HCT-116 and HeLa cells, leading to cancer cell death via apoptosis. Furthermore, compound 10c showed a significant reduction in tumor volume in Swiss albino female mice as an in vivo breast cancer model. Docking results confirmed the tight binding interactions of compound 10c with the VEGFR-2 binding site, with its binding energy surpassing that of sunitinib. In silico PK studies predicted compound 10c to have good oral bioavailability and a good drug score with low human toxicity risks.

Modulating Phosphorylation by Proximity-Inducing Modalities for Cancer Therapy

Abnormal phosphorylation of proteins can lead to various diseases, particularly cancer. Therefore, the development of small molecules for precise regulation of protein phosphorylation holds great potential for drug design. While the traditional kinase/phosphatase small-molecule modulators have shown some success, achieving precise phosphorylation regulation has proven to be challenging. The emergence of heterobifunctional molecules, such as phosphorylation-inducing chimeric small molecules (PHICSs) and phosphatase recruiting chimeras (PHORCs), with proximity-inducing modalities is expected to lead to a breakthrough by specifically recruiting kinase or phosphatase to the protein of interest. Herein, we summarize the drug targets with aberrant phosphorylation in cancer and underscore the potential of correcting phosphorylation in cancer therapy. Through reported cases of heterobifunctional molecules targeting phosphorylation regulation, we highlight the current design strategies and features of these molecules. We also provide a systematic elaboration of the link between aberrantly phosphorylated targets and cancer as well as the existing challenges and future research directions for developing heterobifunctional molecular drugs for phosphorylation regulation.

Harnessing potential COX-2 engagement for boosting anticancer activity of substituted 2-mercapto-4(3H)-quinazolinones with promising EGFR/VEGFR-2 inhibitory activities

We designed and synthesized new quinazolinone-tethered phenyl thiourea/thiadiazole derivatives 4-26. Based on their structural characteristics, these compounds were proposed to have a multi-target mode of action for their anticancer activities. Using the MTT assay method, antiproliferative effects were assessed against three human cancer cell lines (HEPG-2, MCF-7, and HCT-116). In vitro assessment for enzymatic inhibitory activity of the most active compounds 4, 9 and 20 was done for EGFR, VEGFR-2 and COX-2 as potential targets. The screened compounds showed low micromolar IC50 inhibitory effects against the three targets. Compound 9 demonstrated similar EGFR/VEGFR-2 inhibitory effect to the control drugs and potential inhibitory activity for COX-2 enzyme. In MCF-7 cells, the most active analog 9 caused 41.02% total apoptosis, and arrested the cell cycle at the G2/M phase. Taken as a whole, the findings of this study provide significant new understandings into the relationship between COX inhibition and cancer therapy. Furthermore, the outcomes showcased the encouraging efficacy of these compounds with a multi-target mechanism, making them excellent choices for additional research and development into possible anticancer drug.

Synthesis and characterisation of a nucleotide based pro-drug formulated with a peptide into a nano-chemotherapy for colorectal cancer

Recent studies in colorectal cancer patients (CRC) have shown that increased resistance to thymidylate synthase (TS) inhibitors such as 5-fluorouracil (5-FU), reduce the efficacy of standard of care (SoC) treatment regimens. The nucleotide pool cleanser dUTPase is highly expressed in CRC and is an attractive target for potentiating anticancer activity of chemotherapy. The purpose of the current work was to investigate the activity of P1, P4-di(2',5'-dideoxy-5'-selenouridinyl)-tetraphosphate (P4-SedU2), a selenium-modified symmetrically capped dinucleoside with prodrug capabilities that is specifically activated by dUTPase. Using mechanochemistry, P4-SedU2 and the corresponding selenothymidine analogue P4-SeT2 were prepared with a yield of 19% and 30% respectively. The phosphate functionality facilitated complexation with the amphipathic cell-penetrating peptide RALA to produce nanoparticles (NPs). These NPs were designed to deliver P4-SedU2 intracellularly and thereby maximise in vivo activity. The NPs demonstrated effective anti-cancer activity and selectivity in the HCT116 CRC cell line, a cell line that overexpresses dUTPase; compared to HT29 CRC cells and NCTC-929 fibroblast cells which have reduced levels of dUTPase expression. In vivo studies in BALB/c SCID mice revealed no significant toxicity with respect to weight or organ histology. Pharmacokinetic analysis of blood serum showed that RALA facilitates effective delivery and rapid internalisation into surrounding tissues with NPs eliciting lower plasma Cmax than the equivalent injection of free P4-SedU2, translating the in vitro findings. Tumour growth delay studies have demonstrated significant inhibition of growth dynamics with the tumour doubling time extended by >2weeks. These studies demonstrate the functionality and action of a new pro-drug nucleotide for CRC.

Novel thiazolidin-4-one benzenesulfonamide hybrids as PPARγ agonists: Design, synthesis and in vivo anti-diabetic evaluation

In the current study, two series of novel thiazolidin-4-one benzenesulfonamide arylidene hybrids 9a-l and 10a-f were designed, synthesized and tested in vitro for their PPARɣ agonistic activity. The phenethyl thiazolidin-4-one sulphonamide 9l showed the highest PPARɣ activation % by 41.7%. Whereas, the 3-methoxy- and 4-methyl-4-benzyloxy thiazolidin-4-one sulphonamides 9i, and 9k revealed moderate PPARɣ activation % of 31.7, and 32.8%, respectively, in addition, the 3-methoxy-3-benzyloxy thiazolidin-4-one sulphonamide 10d showed PPARɣ activation % of 33.7% compared to pioglitazone. Compounds 9b, 9i, 9k, 9l, and 10d revealed higher selectivity to PPARɣ over the PPARδ, and PPARα isoforms. An immunohistochemical study was performed in HepG-2 cells to confirm the PPARɣ protein expression for the most active compounds. Compounds 9i, 9k, and 10d showed higher PPARɣ expression than that of pioglitazone. Pharmacological studies were also performed to determine the anti-diabetic activity in rats at a dose of 36 mg/kg, and it was revealed that compounds 9i and 10d improved insulin secretion as well as anti-diabetic effects. The 3-methoxy-4-benzyloxy thiazolidin-4-one sulphonamide 9i showed a better anti-diabetic activity than pioglitazone. Moreover, it showed a rise in blood insulin by 4-folds and C-peptide levels by 48.8%, as well as improved insulin sensitivity. Moreover, compound 9i improved diabetic complications as evidenced by decreasing liver serum enzymes, restoration of total protein and kidney functions. Besides, it combated oxidative stress status and exerted anti-hyperlipidemic effect. Compound 9i showed a superior activity by normalizing some parameters and amelioration of pancreatic, hepatic, and renal histopathological alterations caused by STZ-induction of diabetes. Molecular docking studies, molecular dynamic simulations, and protein ligand interaction analysis were also performed for the newly synthesized compounds to investigate their predicted binding pattern and energies in PPARɣ binding site.

The VEGFs/VEGFRs system in Alzheimer's and Parkinson's diseases: Pathophysiological roles and therapeutic implications

The vascular endothelial growth factors (VEGFs) and their cognate receptors (VEGFRs), besides their well-known involvement in physiological angiogenesis/lymphangiogenesis and in diseases associated to pathological vessel formation, play multifaceted functions in the central nervous system (CNS). In addition to shaping brain development, by controlling cerebral vasculogenesis and regulating neurogenesis as well as astrocyte differentiation, the VEGFs/VEGFRs axis exerts essential functions in the adult brain both in physiological and pathological contexts. In this article, after describing the physiological VEGFs/VEGFRs functions in the CNS, we focus on the VEGFs/VEGFRs involvement in neurodegenerative diseases by reviewing the current literature on the rather complex VEGFs/VEGFRs contribution to the pathogenic mechanisms of Alzheimer's (AD) and Parkinson's (PD) diseases. Thereafter, based on the outcome of VEGFs/VEGFRs targeting in animal models of AD and PD, we discuss the factual relevance of pharmacological VEGFs/VEGFRs modulation as a novel and potential disease-modifying approach for these neurodegenerative pathologies. Specific VEGFRs targeting, aimed at selective VEGFR-1 inhibition, while preserving VEGFR-2 signal transduction, appears as a promising strategy to hit the molecular mechanisms underlying AD pathology. Moreover, therapeutic VEGFs-based approaches can be proposed for PD treatment, with the aim of fine-tuning their brain levels to amplify neurotrophic/neuroprotective effects while limiting an excessive impact on vascular permeability.

Design, synthesis, and antitumor screening of new thiazole, thiazolopyrimidine, and thiazolotriazine derivatives as potent inhibitors of VEGFR-2

New thiazole, thiazolopyrimidine, and thiazolotriazine derivatives 3-12 and 14a-f were synthesized. The newly synthesized analogs were tested for in vitro antitumor activity against HepG2, HCT-116, MCF-7, HeP-2, and Hela cancer cells. Results indicated that compound 5 displayed the highest potency toward the tested cancer cells. Compound 11b possessed enhanced effectiveness over MCF-7, HepG2, HCT-116, and Hela cancer cells. In addition, compounds 4 and 6 showed promising activity toward HCT-116, MCF-7, and Hela cancer cells and eminent activity against HepG2 and HeP-2 cells. Moreover, compounds 3-6 and 11b were tested for their capability to inhibit vascular endothelial growth factor receptor-2 (VEGFR-2) activity. The obtained results showed that compound 5 displayed significant inhibitory activity against VEGFR-2 (half-maximal inhibitory concentration [IC50 ] = 0.044 μM) comparable to sunitinib (IC50  = 0.100 μM). Also, the synthesized compounds 3-6 and 11b were subjected to in vitro cytotoxicity tests over WI38 and WISH normal cells. It was found that the five tested compounds displayed significantly lower cytotoxicity than doxorubicin toward normal cell lines. Cell cycle analysis proved that compound 5 induces cell cycle arrest in the S phase for HCT-116 and Hela cancer cell lines and in the G2/M phase for the MCF-7 cancer cell line. Moreover, compound 5 induced cancer cell death through apoptosis accompanied by a high ratio of BAX/BCL-2 in the screened cancer cells. Furthermore, docking results revealed that compound 5 showed the essential interaction bonds with VEGFR-2, which agreed with in vitro enzyme assay results. In silico studies showed that most of the analyzed compounds complied with the requirements of good oral bioavailability with minimal toxicity threats in humans.

Modeling Colorectal Cancer-Induced Liver Portal Vein Microthrombus on a Hepatic Lobule Chip

Colorectal cancer is one of the most common malignant tumors. At the advanced stage of colorectal cancer, cancer cells migrate with the blood to the liver from the hepatic portal vein, eventually resulting in a portal vein tumor thrombus (PVTT). To date, the progression of the early onset of PVTT [portal vein microthrombus (PVmT) induced by tumors] is unclear. Herein, we developed an on-chip PVmT model by loading the spheroid of colorectal cancer cells into the portal vein of a hepatic lobule chip (HLC). On the HLC, the progression of PVmT was presented, and early changes in metabolites of hepatic cells and in structures of hepatic plates and sinusoids induced by PVmT were analyzed. We replicated intrahepatic angiogenesis, thickened blood vessels, an increased number of hepatocytes, disordered hepatic plates, and decreased concentrations of biomarkers of hepatic cell functions in PVmT progression on a microfluidic chip for the first time. In addition, the combined therapy of thermo-ablation and chemo-drug for PVmT was preliminarily demonstrated. This study provides a promising method for understanding PVTT evolution and offers a valuable reference for PVTT therapy.

Integration of Hybridization Strategies in Pyridine-Urea Scaffolds for Novel Anticancer Agents: Design, Synthesis, and Mechanistic Insights

Annually, millions of new cancer cases are reported, leading to millions of deaths worldwide. Among the newly reported cases, breast and colon cancers prevail as the most frequently detected variations. To effectively counteract this rapid increase, the development of innovative therapies is crucial. Small molecules possessing pyridine and urea moieties have been reported in many of the currently available anticancer agents, especially VEGFR2 inhibitors. With this in mind, a rational design approach was employed to create hybrid small molecules combining urea and pyridine. These synthesized compounds underwent in vitro testing against breast and colon cancer cell lines, revealing potent submicromolar anticancer activity. Compound 8a, specifically, exhibited an impressive GI₅₀ value of 0.06 μM against the MCF7 cancer cell line, while compound 8h displayed the highest cytotoxic activity against the HCT116 cell line, with a GI₅₀ of 0.33 ± 0.042 μM. Notably, compounds 8a, 8h, and 8i demonstrated excellent safety profiles when tested on normal cells. Molecular docking, dynamic studies, and free energy calculations were employed to validate the affinity of these compounds as VEGFR2 inhibitors.

Toward Blood-Based Precision Medicine: Identifying Age-Sex-Specific Vascular Biomarker Quantities on Circulating Vascular Cells

Introduction

Abnormal angiogenesis is central to vascular disease and cancer, and noninvasive biomarkers of vascular origin are needed to evaluate patients and therapies. Vascular endothelial growth factor receptors (VEGFRs) are often dysregulated in these diseases, making them promising biomarkers, but the need for an invasive biopsy has limited biomarker research on VEGFRs. Here, we pioneer a blood biopsy approach to quantify VEGFR plasma membrane localization on two circulating vascular proxies: circulating endothelial cells (cECs) and circulating progenitor cells (cPCs).

Methods

Using quantitative flow cytometry, we examined VEGFR expression on cECs and cPCs in four age-sex groups: peri/premenopausal females (aged < 50 years), menopausal/postmenopausal females (≥ 50 years), and younger and older males with the same age cut-off (50 years).

Results

cECs in peri/premenopausal females consisted of two VEGFR populations: VEGFR-low (~ 55% of population: population medians ~ 3000 VEGFR1 and 3000 VEGFR2/cell) and VEGFR-high (~ 45%: 138,000 VEGFR1 and 39,000-236,000 VEGFR2/cell), while the menopausal/postmenopausal group only possessed the VEGFR-low cEC population; and 27% of cECs in males exhibited high plasma membrane VEGFR expression (206,000 VEGFR1 and 155,000 VEGFR2/cell). The absence of VEGFR-high cEC subpopulations in menopausal/postmenopausal females suggests that their high-VEGFR cECs are associated with menstruation and could be noninvasive proxies for studying the intersection of age-sex in angiogenesis. VEGFR1 plasma membrane localization in cPCs was detected only in menopausal/postmenopausal females, suggesting a menopause-specific regenerative mechanism.

Conclusions

Overall, our quantitative, noninvasive approach targeting cECs and cPCs has provided the first insights into how sex and age influence VEGFR plasma membrane localization in vascular cells.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12195-023-00771-1.

Novel 2-oxo-2-phenylethoxy and benzyloxy diaryl urea hybrids as VEGFR-2 inhibitors: Design, synthesis, and anticancer evaluation

Two series of diaryl urea derivatives, 6a-k and 7a-n, were synthesized. All the newly synthesized compounds were tested against the NCI (US) cancer cell lines via SRB assay. The p-chloro-m-trifluoromethyl phenyl derivatives 6e-g and 7e-g showed the most potent cytotoxic activity with a GI₅₀ value range of 1.2-15.9 µM. Furthermore, the p-fluorobenzyloxy diaryl urea derivative 7g revealed the most potent cytotoxicity against eight cancer cell lines in the MTT assay with IC₅₀ values below 5 µM. Compounds 6a-k and 7a-n were tested for their vascular endothelial growth factor receptor-2 (VEGFR-2) kinase inhibitory activities. The p-chloro-m-trifluoromethyl diaryl urea benzyloxy derivatives 7e-i and the p-methoxydiaryl urea benzyloxy derivatives 7k, 7l, and 7n were found to be the most active compounds as VEGFR-2 inhibitors in the benzyloxy series 7, with an IC₅₀ range of 0.09-4.15 µM. In the 2-oxo-2-phenylethoxy series 6, compounds 6e-g and 6i were reported with IC₅₀ values of 0.94, 0.54, 2.71, and 4.81 µM, respectively. Moreover, compounds 7e and 7g induced apoptosis, causing cell cycle arrest in the G2/M phase. In addition, 7g showed an antimigratory effect in A-375 cells and inhibited the VEGFR-2 expression in an immunohistofluorescence study. Molecular docking simulations on VEGFR-2 as well as ADME properties prediction were also performed.

Cancer Cell De-Differentiation: Plasticity-Driven Stratagem For Tumor Metastasis and Recurrence

Tumor recurrence is a colossal challenge in clinical oncology. This multifactorial problem is attributed to the emergence of additional genetic mutations and the presence of dormant cancer cells. However, the plasticity of non-stem cancer cells and the acquisition of cancer stem cell (CSC) functionality is another contributing factor to tumor recurrence. Herein, I focus attention on the mechanisms that fuel cancer cell de-differentiation and the interplay between intra-cellular regulators and tumor microenvironment (TME) landscape that promotes cancer cell stemness. Our understanding of the mechanisms underlying tumor cell de-differentiation is crucial for developing innovative therapeutic strategies that prevent cancer from ever recurring.

A zebrafish HCT116 xenograft model to predict anandamide outcomes on colorectal cancer

Colon cancer is one of the leading causes of death worldwide. In recent years, cannabinoids have been extensively studied for their potential anticancer effects and symptom management. Several in vitro studies reported anandamide's (AEA) ability to block cancer cell proliferation and migration, but evidence from in vivo studies is still lacking. Thus, in this study, the effects of AEA exposure in zebrafish embryos transplanted with HCT116 cells were evaluated. Totally, 48 hpf xenografts were exposed to 10 nM AEA, 10 nM AM251, one of the cannabinoid 1 receptor (CB1) antagonist/inverse agonists, and to AEA + AM251, to verify the specific effect of AEA treatment. AEA efficacy was evaluated by confocal microscopy, which demonstrated that these xenografts presented a smaller tumor size, reduced tumor angiogenesis, and lacked micrometastasis formation. To gain deeper evidence into AEA action, microscopic observations were completed by molecular analyses. RNA seq performed on zebrafish transcriptome reported the downregulation of genes involved in cell proliferation, angiogenesis, and the immune system. Conversely, HCT116 cell transcripts resulted not affected by AEA treatment. In vitro HCT116 culture, in fact, confirmed that AEA exposure did not affect cell proliferation and viability, thus suggesting that the reduced tumor size mainly depends on direct effects on the fish rather than on the transplanted cancer cells. AEA reduced cell proliferation and tumor angiogenesis, as suggested by socs3 and pcnp mRNAs and Vegfc protein levels, and exerted anti-inflammatory activity, as indicated by the reduction of il-11a, mhc1uba, and csf3b mRNA. Of note, are the results obtained in groups exposed to AM251, which presence nullifies AEA's beneficial effects. In conclusion, this study promotes the efficacy of AEA in personalized cancer therapy, as suggested by its ability to drive tumor growth and metastasis, and strongly supports the use of zebrafish xenograft as an emerging model platform for cancer studies.

6 Iodo-delta lactone inhibits angiogenesis in human HT29 colon adenocarcinoma xenograft

INTRODUCTION

Several studies have shown the antiproliferative effect of iodine and 5‑hydroxy-6 iodo-eicosatrienoic delta lactone (IL-δ) on diverse tissues. It was demonstrated that molecular iodine (I₂) and IL-δ, but not iodide (I^-), exerts anti-neoplastic actions in different cancers. The underlying mechanism through which IL-δ inhibits tumor growth remains unclear. The aim of this study was to analyze the effect of IL-δ on tumor growth and angiogenesis in human HT29 colorectal cancer xenografts.

METHODOLOGY AND RESULTS

HT29 cells were injected subcutaneously into the flanks of nude mice and IL-δ was i.p. injected at a dose of 15 μg three days a week. IL-δ treatment in HT29 xenografts showed time-dependent inhibition of tumor growth, decrease of mitosis and PCNA expression (p < 0.05), increase of P27 expression and Caspase 3 activity after 18 days of treatment (p < 0.05). To assess tumor Microvessel Densities (MVD), CD31 staining by immunohistochemistry was analyzed. IL-δ treatment decreased MVD by 17% and 30% after 18 and 30 days respectively (p < 0.05), as well as it decreased VEGF and VEGF-R2 expression (p < 0.05). Additionally, our findings demonstrated that IL-δ increased VEGF-R1 and Ang-1 mRNA levels (p < 0.01).

CONCLUSION

The antitumor efficacy of IL-δ in vivo involves inhibition of cell proliferation as well as induction of apoptosis. IL-δ has also anti-angiogenic effect associated with VEGF and VEGF-R2 downregulation followed by Ang-1 and VEGF-R1 increased expression. High levels of Ang-1 would contribute to mature vessel stabilization and maintenance while VEGF-R1 increase would produce anti-proliferative effect on endothelial cells.

The Comparative Role of BAMLET and 5-Fluorouracil in Colorectal Cancer Cells by Targeting WNT/&amp; Beta; -Catenin Pathway

Background: Aberrant activation of the WNT/β-catenin signaling pathway is involved in various types of cancers, particularly colorectal cancer (CRC), which is a prevalent malignancy. Targeting the Wnt signaling pathway has gained a reputation as an attractive therapeutic strategy, mainly because of its potential for regulating cell proliferation, migration, differentiation, angiogenesis, and apoptosis. Objectives: The aim of the current research was to investigate the effects of 5-Fluorouracil (5-FU) and bovine alpha-lactalbumin made lethal to tumor cells (BAMLET), a complex of oleic acid with bovine α-lactalbumin protein, on colon cancer cells focusing on the Wnt signaling pathway. Methods: For this purpose, HT-29 and HCT116 cells were treated with 5-FU and BAMLET, and the expression levels of Wnt signaling-related proteins (β-catenin and E-cadherin) and VEGF as angiogenesis regulators were evaluated by quantitative real-time polymerase chain reaction (RT-qPCR) and Western Blot analysis. Results: Bovine alpha-lactalbumin made lethal to tumor cells (BAMLET) treatment down-regulated the expression of β-catenin and up-regulated the expression of E-cadherin significantly compared to the 5-FU (P < 0.0001). The reduced mRNA levels of VEGF in treated cells revealed the effectiveness of 5-FU and BAMLET on angiogenesis. Conclusions: Bovine alpha-lactalbumin made lethal to tumor cells (BAMLET) can be considered for targeting the Wnt signaling pathway and angiogenesis. It is amenable to further investigation in the development of CRC treatment.

Case report: Post-therapeutic laryngeal carcinoma patient possessing a high ratio of aneuploid CTECs to CTCs rapidly developed de novo malignancy in pancreas

Effectively evaluating therapeutic efficacy, detecting minimal residual disease (MRD) after therapy completion, and predicting early occurrence of malignancy in cancer patients remain as unmet imperative clinical demands. This article presents a case of a laryngeal carcinoma patient who had a surgical resection and complete post-operative chemoradiotherapy in combination with the targeted therapy, then rapidly developed pancreatic adenocarcinoma. Detected by SE-iFISH, the patient had a substantial amount of 107 non-hematological aneuploid circulating rare cells including 14 circulating tumor cells (CTCs, CD31-/CD45-) and 93 circulating tumor endothelial cells (CTECs, CD31+/CD45-) with a high ratio of CTECs/CTCs &gt; 5 upon finishing post-surgical combination regimens. Positive detection of those aneuploid non-hematological circulating rare cells was five months prior to subsequent plasma CA19-9 increasing and ten months before the de novo pancreatic cancer was diagnosed by medical imaging modalities. Besides previously reported clinical utilities of co-detection of aneuploid CD31- CTCs and CD31+ CTECs in real-time evaluation of therapeutic efficacy, longitudinal monitoring of emerging treatment resistance and adequate detection of MRD, a large cohort study is necessary to further investigate whether, and how, a high ratio of MRD CTECs to CTCs may function as an appropriate index forecasting either occurrence or metastatic distant recurrence of malignancy in post-therapeutic cancer patients.

Cancer Stem Cells and Their Possible Implications in Cervical Cancer: A Short Review

Cervical cancer (CC) is the fourth most common type of gynecological malignancy affecting females worldwide. Most CC cases are linked to infection with high-risk human papillomaviruses (HPV). There has been a significant decrease in the incidence and death rate of CC due to effective cervical Pap smear screening and administration of vaccines. However, this is not equally available throughout different societies. The prognosis of patients with advanced or recurrent CC is particularly poor, with a one-year relative survival rate of a maximum of 20%. Increasing evidence suggests that cancer stem cells (CSCs) may play an important role in CC tumorigenesis, metastasis, relapse, and chemo/radio-resistance, thus representing potential targets for a better therapeutic outcome. CSCs are a small subpopulation of tumor cells with self-renewing ability, which can differentiate into heterogeneous tumor cell types, thus creating a progeny of cells constituting the bulk of tumors. Since cervical CSCs (CCSC) are difficult to identify, this has led to the search for different markers (e.g., ABCG2, ITGA6 (CD49f), PROM1 (CD133), KRT17 (CK17), MSI1, POU5F1 (OCT4), and SOX2). Promising therapeutic strategies targeting CSC-signaling pathways and the CSC niche are currently under development. Here, we provide an overview of CC and CCSCs, describing the phenotypes of CCSCs and the potential of targeting CCSCs in the management of CC.

New quinoxalin-2(1H)-one-derived VEGFR-2 inhibitors: Design, synthesis, in vitro anticancer evaluations, in silico ADMET, and docking studies

More than 70% of cancer patients who are treated with chemotherapeutics do not show a durable response. As part of the global plan seeking new effective chemotherapeutics, here, we report the synthesis and in vitro and computational studies of new lenvatinib and sorafenib analog quinoxalines as vascular endothelial growth factor receptor II (VEGFR-2) tyrosine kinase inhibitors. The central quinolone and pyridine moieties of the Food and Drug Administration-approved anticancer agents lenvatinib and sorafenib were replaced with the versatile quinoxaline scaffold that has been exploited for developing potent cytotoxic agents. With some minor structural optimizations, all the other pharmacophoric features of lenvatinib and sorafenib were maintained. Accordingly, three new sets of quinoxalines were synthesized to evaluate their activity against liver, colorectal, and breast malignancies. The results obtained in the in vitro cytotoxicity evaluation study revealed the superior activity of three derivatives (20, 25, and 29) compared with that of doxorubicin and sorafenib. Absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiling and docking of 20, 25, and 29 into the VEGFR-2 receptor were also performed. Results of in silico studies showed the potential of the designed compounds to bind effectively with a number of key residues. The obtained in vitro cytotoxic activity and ADMET profiles of compounds 20, 25, and 29 suggested that they should be subjected to further structural optimizations to develop new candidates in cancer treatment protocols.

DIX domain containing 1 (DIXDC1) modulates VEGFR2 level in vasculatures to regulate embryonic and postnatal retina angiogenesis

Background

In sprouting angiogenesis, VEGFR2 level is regulated via a fine-tuned process involving various signaling pathways. Other than VEGF/VEGFR2 signaling pathway, Wnt/ β-catenin signaling is also important in vascular development. However, the crosstalk between these two signaling pathways is still unknown to date. In this study, we aimed to investigate the role of DIX domain containing 1 (DIXDC1) in vasculature, facilitating the crosstalk between VEGF/VEGFR2 and Wnt/ β-catenin signaling pathways.

Results

In mice, DIXDC1 deficiency delayed angiogenesis at the embryonic stage and suppressed neovascularization at the neonatal stage. DIXDC1 knockdown inhibited VEGF-induced angiogenesis in endothelial cells in vitro by downregulating VEGFR2 expression. DIXDC1 bound Dishevelled Segment Polarity Protein 2 (Dvl2) and polymerized Dvl2 stabilizing VEGFR2 protein via its direct interaction. The complex formation and stability of VEGFR2 was potentiated by Wnt signaling. Moreover, hypoxia elevated DIXDC1 expression and likely modulated both canonical Wnt/β-catenin signaling and VEGFR2 stability in vasculatures. Pathological angiogenesis in DIXDC1 knockout mice was decreased significantly in oxygen-induced retinopathy (OIR) and in wound healing models. These results suggest that DIXDC1 is an important factor in developmental and pathological angiogenesis.

Conclusion

We have identified DIXDC1 as an important factor in early vascular development. These results suggest that DIXDC1 represents a novel regulator of sprouting angiogenesis that links Wnt signaling and VEGFR2 stability and may have a potential role in pathological neovascularization.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12915-022-01240-3.

Molecular design, synthesis and in vitro biological evaluation of thienopyrimidine-hydroxamic acids as chimeric kinase HDAC inhibitors: a challenging approach to combat cancer

A series of thieno[2,3-d]pyrimidine-based hydroxamic acid hybrids was designed and synthesised as multitarget anti-cancer agents, through incorporating the pharmacophore of EGFR, VEGFR2 into the inhibitory functionality of HDAC6. Three compounds (12c, 15b and 20b) were promising hits, whereas (12c) exhibited potent VEGFR2 inhibition (IC50=185 nM), potent EGFR inhibition (IC50=1.14 µM), and mild HDAC6 inhibition (23% inhibition). Moreover, compound (15c) was the most potent dual inhibitor among all the synthesised compounds, as it exhibited potent EGFR and VEGFR2 inhibition (IC50=19 nM) and (IC50=5.58 µM), respectively. While compounds (20d) and (7c) displayed nanomolar selective kinase inhibition with EGFR IC50= 68 nM and VEGFR2 IC50= 191 nM, respectively. All of the synthesised compounds were screened in vitro for their cytotoxic effect on 60 human NCI tumour cell lines. Additionally, molecular docking studies and ADMET studies were carried out to gain further insight into their binding mode and predict the pharmacokinetic properties of all the synthesised inhibitors.

Lactobacillus fermentum ZS09 Mediates Epithelial–Mesenchymal Transition (EMT) by Regulating the Transcriptional Activity of the Wnt/β-Catenin Signalling Pathway to Inhibit Colon Cancer Activity

Objective

The epithelial–mesenchymal transition (EMT) pathway can mediate tumour migration, and the occurrence of EMT is closely related to the Wnt/β-catenin signalling pathway. The purpose of this paper was to study the effect of Lactobacillus fermentum ZS09 (L. fermentum ZS09) on the EMT pathway in mouse with azoxymethane/dextran sulfate sodium salt (AOM/DSS) induced colon cancer and the potential underlying mechanism.

Materials and Methods

In this study, a mouse colon cancer model was established through intraperitoneal injection of 10 mg/kg azoxymethane (AOM) and three cycles of 2.5% dextran sulfate sodium salt (DSS) in the drinking water. H&E staining, enzyme-linked immunosorbent assay (ELISA), real-time fluorescent quantitative PCR (RT-qPCR) and Western blotting (WB) were used to study the antitumour mechanisms of L. fermentum ZS09 through the EMT pathway.

Results

The results of this study showed that compared with the model group, the high-dose L. fermentum ZS09 intervention group exhibited decreased serum levels of MMP-9, TNF-α, IL-6R, Ang-2 and VEGFR-2 and increased contents of DKK1 (P<0.05). The expression of Wnt/β-catenin signalling pathway-related genes (Dv1, GSK-3β, β-catenin, c-myc, cyclinD1, Vim, and MMP-9) was significantly reduced, and the gene expression levels of APC, CDH1, and Axin were increased. The levels of related proteins (β-catenin, N-cadherin, and VEGF) were downregulated, and the levels of p-β-catenin and E-cadherin were upregulated.

Conclusion

The results indicate that L. fermentum ZS09 could inhibit EMT and angiogenesis pathways by inhibiting the Wnt/β-catenin signalling pathway, which could inhibit tumour metastasis.

Involvement of parathyroid hormone-related peptide in the aggressive phenotype of colorectal cancer cells

Colorectal cancer (CRC) remains one of the leading causes of mortality from malignant diseases worldwide. In general terms, CRC presents high heterogeneity due to the influence of different genetic and environmental factors; also, the neoplastic cells are strongly influenced by the extracellular matrix and several surrounding cells, known together as the tumor microenvironment (TME). Bidirectional communication takes place between the tumor and the TME through the release of autocrine and paracrine factors. Parathyroid hormone-related peptide (PTHrP) is a cytokine secreted by a wide variety of tissues and is able to regulate several cellular functions both in physiological as well as in pathological processes. It exerts its effects as a paracrine/autocrine factor, although its mode of action is mainly paracrine. It has been shown that this peptide is expressed by several tumors and that the tumor secretion of PTHrP is responsible for the malignant humoral hypercalcemia. Eight years ago, when our research group started studying PTHrP effects in the experimental models derived from intestinal tumors, the literature available at the time addressing the effects of PTHrP on colorectal tumors was limited, and no articles had been published regarding to the paracrine action of PTHrP in CRC cells. Based on this and on our previous findings regarding the role of PTH in CRC cells, our purpose in recent years has been to explore the role of PTHrP in CRC. We analyzed the behavior of CRC cells treated with exogenous PTHrP, focalizing in the study of the following events: Survival, cell cycle progression and proliferation, migration, chemoresistance, tumor-associated angiogenesis, epithelial to mesenchymal transition program and other events also associated with invasion, such us the induction of cancer stem cells features. This work summarizes the major findings obtained by our investigation group using in vitro and in vivo CRC models that evidence the participation of PTHrP in the acquisition of an aggressive phenotype of CRC cells and the molecular mechanisms involved in these processes. Recently, we found that this cytokine induces this malignant behavior not only by its direct action on these intestinal cells but also through its influence on cells derived from TME, promoting a communication between CRC cells and surrounding cells that contributes to the molecular and morphological changes observed in CRC cells. These investigations establish the basis for our next studies in order to address the clinical applicability of our findings. Recognizing the factors and mechanisms that promote invasion in CRC cells, evasion to the cytotoxic effects of current CRC therapies and thus metastasis is decisive for the identification of new markers with the potential to improve early diagnosis and/or to predict prognosis, to predetermine drug resistance and to provide treatment guidelines that include targeted therapies for this disease.

Design, synthesis, docking, and anticancer evaluations of phthalazines as VEGFR-2 inhibitors

Twenty new N-substituted-4-phenylphthalazin-1-amine derivatives were designed, synthesized, and evaluated for their anticancer activities against HepG2, HCT-116, and MCF-7 cells as VEGFR-2 inhibitors. HCT-116 was the most sensitive cell line to the influence of the new derivatives. In particular, compound 7f was found to be the most potent derivative among all the tested compounds against the three cancer cell lines, with 50% inhibition concentration, IC₅₀  = 3.97, 4.83, and 4.58 µM, respectively, which is more potent than both sorafenib (IC₅₀  = 9.18, 5.47, and 7.26 µM, respectively) and doxorubicin (IC₅₀  = 7.94, 8.07, and 6.75 µM, respectively). Fifteen of the synthesized derivatives were selected to evaluate their inhibitory activities against VEGFR-2. Compound 7f was found to be the most potent derivative that inhibited VEGFR-2 at an IC₅₀ value of 0.08 µM, which is more potent than sorafenib (IC₅₀  = 0.10 µM). Compound 8c inhibited VEGFR-2 at an IC₅₀ value of 0.10 µM, which is equipotent to sorafenib. Moreover, compound 7a showed very good activity with IC₅₀ values of 0.11 µM, which is nearly equipotent to sorafenib. In addition, compounds 7d, 7c, and 7g possessed very good VEGFR-2-inhibitory activity, with IC₅₀ values of 0.14, 0.17, and 0.23 µM, respectively.

Phthalazine-based VEGFR-2 inhibitors: Rationale, design, synthesis, in silico, ADMET profile, docking, and anticancer evaluations

In the designed compounds, a new linker was inserted in the form of fragments with verified VEGFR-2 inhibitory potential, including an α,β-unsaturated ketonic fragment, pyrazole, and pyrimidine. Also, new distal hydrophobic moieties were attached to these linkers that are expected to increase the hydrophobic interaction with VEGFR-2 and, consequently, the affinity. These structural optimizations have led us to identify the novel dihydropyrazole derivative 6_e as a promising hit molecule. All the new derivatives were evaluated to assess their anticancer activity against three human cancer cell lines, including HepG2, HCT-116, and MCF-7. The results of the in vitro anticancer evaluation study revealed the moderate to excellent cytotoxicity of 6_c , 6_e , 6_g , and 7_b , with IC₅₀ values in the low micromolar range. The inhibitory activity of VEGFR-2 was investigated for 16 of the designed compounds. The enzyme assay results of the new compounds were compared with those of sorafenib as a reference VEGFR-2 inhibitor. The obtained results demonstrated that our derivatives are potent VEGFR-2 inhibitors. The most potent derivatives 6_c , 6_e , 6_g , and 7_b showed IC₅₀ values in the range of 0.11-0.22 µM. Molecular docking and pharmacokinetic studies were also conducted to rationalize the VEGFR-2 inhibitory activity and to evaluate the ability of the most potent derivatives to be developed as good drug candidates.

Dual role of WNT5A in promoting endothelial differentiation of glioma stem cells and angiogenesis of glioma derived endothelial cells

Glioma is a devastating cancer with a rich vascular network. No anti-angiogenic treatment is available for prolonging the overall survival of glioma patients. Recent studies have demonstrated that the endothelial differentiation of glioma stem cells (GSCs) into glioma-derived endothelial cells (GDECs) may be a novel target for anti-angiogenic therapy in glioma; however, the underlying mechanisms of this process remain unknown. Here, we report that wingless-related integration site (WNT) family member 5A (WNT5A) plays significant roles in GSC endothelial differentiation and GDECs angiogenesis. WNT5A is preferentially secreted by GDECs, and inhibition of WNT5A suppresses angiogenesis and tumorigenesis in GDECs. Silencing of WNT5A in GDECs also disrupts the impact of GDECs on stimulating GSC endothelial differentiation. Frizzled-4 is a receptor that mediates the effect of WNT5A on GSC endothelial differentiation and angiogenesis of GDECs via GSK3β/β-catenin/epithelial-mesenchymal transition signalling. The shWNT5A@cRGD-DDD liposomes, targeting WNT5A, exert anti-angiogenic effects in vivo. In this study, we identified that WNT5A has a dual functional role in modulating the endothelial differentiation of GSCs and angiogenesis of GDECs, indicating that WNT5A is a potential target for anti-angiogenesis-based therapeutics in glioma.

Quercetin Inhibits Colorectal Cancer Cells Induced-Angiogenesis in Both Colorectal Cancer Cell and Endothelial Cell through Downregulation of VEGF-A/VEGFR2

Colorectal cancer (CRC) aggressiveness is caused by cancer angiogenesis which promotes the cancer growth and metastasis associated with poor prognosis and poor survival. The vascular endothelial growth factor-A (VEGF-A) and its receptor (VEGFR-2) form the major signaling pathway in cancer angiogenesis. This study aimed to investigate the anti-angiogenesis activity of quercetin in both colorectal cancer cells and endothelial cells. The tube formation of human vein endothelial cells (HUVECs) was determined by using conditioned media of HT-29 cells treated with quercetin co-cultured with HUVECs. The VEGF-A and NF-κB p65 protein expressions in the quercetin-treated HT-29 cells were determined by fluorescence assay and Western blot analysis. The VEGFR-2 protein expression in HUVECs was determined after they were co-cultured with the quercetin-treated HT-29 cells. Quercetin markedly decreased the HT-29 cell-induced angiogenesis in HUVECs. NF-κB p65 and VEGF-A protein expression were also inhibited by quercetin. Moreover, quercetin significantly inhibited VEGFR-2 expression and translocation in HUVECs after they were co-cultured with high dose quercetin-treated HT-29 cells. Taken together, quercetin had an anti-angiogenesis effect on VEGF-A inhibition related to the NF-κB signaling pathway in the HT-29 cells and reduced VEGFR-2 expression and translocation in HUVECs.

Sustained oxidative stress instigates differentiation of cancer stem cells into tumor endothelial cells: Pentose phosphate pathway, reactive oxygen species and autophagy crosstalk

Tumor angiogenesis plays a vital role in tumor growth and metastasis. It is proven that in tumor vasculature, endothelial cells (ECs) originate from a small population of cancer cells introduced as cancer stem cells (CSCs). Autophagy has a vital role in ECs differentiation from CSCs and tumor angiogenesis. High levels of reactive oxygen species (ROS) increased autophagy by inhibition of glucose-6-phosphate dehydrogenase (G6PD) and inactivation of the pentose phosphate pathway (PPP). Previously, we suggested that cancer cells initially increase the glycolysis rate when encountering ROS, then the metabolic balance is changed from glycolysis to PPP, following the continuation of oxidative stress. In this study, we investigate the possible role of persistent oxidative stress in the differentiation of CSCs into tumor ECs by relying on the relationship between the ROS, PPP and autophagy. Because tumor angiogenesis plays an important role in the growth and development of cancer, understanding the mechanisms involved in differentiating ECs from CSCs can help find promising treatments for cancer.

Design, synthesis, docking, ADMET profile, and anticancer evaluations of novel thiazolidine-2,4-dione derivatives as VEGFR-2 inhibitors

The anticancer activity of novel thiazolidine-2,4-diones was evaluated against HepG2, HCT-116, and MCF-7 cells. Among the tested cancer cell lines, HCT-116 was the most sensitive one to the cytotoxic effect of the new derivatives. In particular, compounds 18, 11, and 10 were found to be the most potent derivatives among all the tested compounds against the HepG2, HCT-116, and MCF-7 cancer cell lines, with IC₅₀ values ranging from 38.76 to 53.99 µM. The most active antiproliferative derivatives (7-14 and 15-19) were subjected to further biological studies to evaluate their inhibitory potentials against VEGFR-2. The tested compounds displayed a good-to-medium inhibitory activity, with IC₅₀ values ranging from 0.26 to 0.72 µM. Among them, compounds 18, 11, and 10 potently inhibited VEGFR-2 at IC₅₀ values in the range of 0.26-0.29 µM, which are nearly three times that of the sorafenib IC₅₀ value (0.10 µM). Although our derivatives showed lower activities than the reference drug, they could be useful as a template for future design, optimization, adaptation, and investigation to produce more potent and selective VEGFR-2 inhibitors with higher anticancer analogs. The ADMET profile showed that compounds 18, 11, and 10 do not violate any of Lipinski's rules and have a comparable intestinal absorptivity in humans. Also, the new derivatives could not inhibit cytochrome P3A4. Unlike sorafenib and doxorubicin, compounds 18, 11, and 10 are expected to have prolonged dosing intervals. Moreover, compounds 10 and 18 displayed a wide therapeutic index and higher selectivity against cancer cells as compared with their cytotoxicity against normal cells.

Angiogenesis-Related Functions of Wnt Signaling in Colorectal Carcinogenesis

Simple Summary

Angiogenesis belongs to the most clinical characteristics of colorectal cancer (CRC) and is strongly linked to the activation of Wnt/β-catenin signaling. The most prominent factors stimulating constitutive activation of this pathway, and in consequence angiogenesis, are genetic alterations (mainly mutations) concerning APC and the β-catenin encoding gene (CTNNB1), detected in a large majority of CRC patients. Wnt/β-catenin signaling is involved in the basic types of vascularization (sprouting and nonsprouting angiogenesis), vasculogenic mimicry as well as the formation of mosaic vessels. The number of known Wnt/β-catenin signaling components and other pathways interacting with Wnt signaling, regulating angiogenesis, and enabling CRC progression continuously increases. This review summarizes the current knowledge about the role of the Wnt/Fzd/β-catenin signaling pathway in the process of CRC angiogenesis, aiming to improve the understanding of the mechanisms of metastasis as well as improvements in the management of this cancer.

Abstract

Aberrant activation of the Wnt/Fzd/β-catenin signaling pathway is one of the major molecular mechanisms of colorectal cancer (CRC) development and progression. On the other hand, one of the most common clinical CRC characteristics include high levels of angiogenesis, which is a key event in cancer cell dissemination and distant metastasis. The canonical Wnt/β-catenin downstream signaling regulates the most important pro-angiogenic molecules including vascular endothelial growth factor (VEGF) family members, matrix metalloproteinases (MMPs), and chemokines. Furthermore, mutations of the β-catenin gene associated with nuclear localization of the protein have been mainly detected in microsatellite unstable CRC. Elevated nuclear β-catenin increases the expression of many genes involved in tumor angiogenesis. Factors regulating angiogenesis with the participation of Wnt/β-catenin signaling include different groups of biologically active molecules including Wnt pathway components (e.g., Wnt2, DKK, BCL9 proteins), and non-Wnt pathway factors (e.g., chemoattractant cytokines, enzymatic proteins, and bioactive compounds of plants). Several lines of evidence argue for the use of angiogenesis inhibition in the treatment of CRC. In the context of this paper, components of the Wnt pathway are among the most promising targets for CRC therapy. This review summarizes the current knowledge about the role of the Wnt/Fzd/β-catenin signaling pathway in the process of CRC angiogenesis, aiming to improve the understanding of the mechanisms of metastasis as well as improvements in the management of this cancer.

N-Substituted-4-phenylphthalazin-1-amine-derived VEGFR-2 inhibitors: Design, synthesis, molecular docking, and anticancer evaluation studies

In accordance with the significant impetus of the discovery of potent vascular endothelial growth factor receptor 2 (VEGFR-2) inhibitors, herein, we report the design, synthesis, and anticancer evaluation of 12 new N-substituted-4-phenylphthalazin-1-amine derivatives against HepG2, HCT-116, and MCF-7 cells as VEGFR-2 inhibitors. The results of the cytotoxicity investigation indicated that HCT-116 and MCF-7 were the most sensitive cell lines to the influence of the newly synthesized derivatives. In particular, compound 7a was found to be the most potent derivative among all the tested compounds against the three cancer cell lines, HepG2, HCT116, and MCF-7, with IC₅₀  = 13.67 ± 1.2, 5.48 ± 0.4, and 7.34 ± 0.6 µM, respectively, which is nearly equipotent to that of sorafenib (IC₅₀  = 9.18 ± 0.6, 5.47 ± 0.3, and 7.26 ± 0.3 µM, respectively). All synthesized derivatives, 4a,b-8a-c, were evaluated for their inhibitory activities against VEGFR-2. The tested compounds displayed high to low inhibitory activity, with IC₅₀ values ranging from 0.14 ± 0.02 to 9.54 ± 0.85 µM. Among them, compound 7a was found to be the most potent derivative that inhibited VEGFR-2 at an IC₅₀ value of 0.14 ± 0.02 µM, which is nearly 72% of that of the sorafenib IC₅₀ value (0.10 ± 0.02 µM). Compounds 7b, 8c, 8b, and 8a exhibited very good activity with IC₅₀ values of 0.18 ± 0.02, 0.21 ± 0.03, 0.24 ± 0.02, and 0.35 ± 0.04 µM, respectively. Molecular modeling studies were carried out for all compounds against the VEGFR-2 active site. The data obtained from biological testing highly correlated with that obtained from molecular modeling studies. However, these modifications led to new phthalazine derivatives with higher VEGFR-2 inhibitory activities than vatalanib and which are nearly equipotent to sorafenib.

Design, synthesis, and anti-proliferative evaluation of new quinazolin-4(3H)-ones as potential VEGFR-2 inhibitors

Inhibiting VEGFR-2 has been set up as a therapeutic strategy for treatment of cancer. Thus, nineteen new quinazoline-4(3H)-one derivatives were designed and synthesized. Preliminary cytotoxicity studies of the synthesized compounds were evaluated against three human cancer cell lines (HepG-2, MCF-7 and HCT-116) using MTT assay method. Doxorubicin and sorafenib were used as positive controls. Five compounds were found to have promising cytotoxic activities against all cell lines. Compound 16_f, containing a 2-chloro-5-nitrophenyl group, has emerged as the most active member. It was approximately 4.39-, 5.73- and 1.96-fold more active than doxorubicin and 3.88-, 5.59- and 1.84-fold more active than sorafenib against HepG2, HCT-116 and MCF-7 cells, respectively. The most active cytotoxic agents were further evaluated in vitro for their VEGFR-2 inhibitory activities. The results of in vitro VEGFR-2 inhibition were consistent with that of the cytotoxicity data. Molecular docking of these compounds into the kinase domain, moreover, supported the results.

Dual Targeting of Endothelial and Cancer Cells Potentiates In Vitro Nanobody-Targeted Photodynamic Therapy

Photodynamic therapy (PDT) induces cell death through local light activation of a photosensitizer, although sub-optimal tumor specificity and side effects have hindered its clinical application. We introduced a new strategy named nanobody-targeted PDT in which photosensitizers are delivered to tumor cells by means of nanobodies. As efficacy of targeted PDT can be hampered by heterogeneity of target expression and/or moderate/low target expression levels, we explored the possibility of combined targeting of endothelial and cancer cells in vitro. We developed nanobodies binding to the mouse VEGFR2, which is overexpressed on tumor vasculature, and combined these with nanobodies specific for the cancer cell target EGFR. The nanobodies were conjugated to the photosensitizer IRDye700DX and specificity of the newly developed nanobodies was verified using several endothelial cell lines. The cytotoxicity of these conjugates was assessed in monocultures and in co-cultures with cancer cells, after illumination with an appropriate laser. The results show that the anti-VEGFR2 conjugates are specific and potent PDT agents. Nanobody-targeted PDT on co-culture of endothelial and cancer cells showed improved efficacy, when VEGFR2 and EGFR targeting nanobodies were applied simultaneously. Altogether, dual targeting of endothelial and cancer cells is a promising novel therapeutic strategy for more effective nanobody-targeted PDT.

Role of VEGF-A and LRG1 in Abnormal Angiogenesis Associated With Diabetic Nephropathy

Diabetic nephropathy (DN) is an important public health concern of increasing proportions and the leading cause of end-stage renal disease (ESRD) in diabetic patients. It is one of the most common long-term microvascular complications of diabetes mellitus that is characterized by proteinuria and glomerular structural changes. Angiogenesis has long been considered to contribute to the pathogenesis of DN, whereas the molecular mechanisms of which are barely known. Angiogenic factors associated with angiogenesis are the major candidates to explain the microvascular and pathologic finds of DN. Vascular endothelial growth factor A (VEGF-A), leucine-rich α-2-glycoprotein 1, angiopoietins and vasohibin family signal between the podocytes, endothelium, and mesangium have important roles in the maintenance of renal functions. An appropriate amount of VEGF-A is beneficial to maintaining glomerular structure, while excessive VEGF-A can lead to abnormal angiogenesis. LRG1 is a novel pro-angiogenic factors involved in the abnormal angiogenesis and renal fibrosis in DN. The imbalance of Ang1/Ang2 ratio has a role in leading to glomerular disease. Vasohibin-2 is recently shown to be in diabetes-induced glomerular alterations. This review will focus on current understanding of these angiogenic factors in angiogenesis and pathogenesis associated with the development of DN, with the aim of evaluating the potential of anti-angiogenesis therapy in patients with DN.

Aneuploid Circulating Tumor-Derived Endothelial Cell (CTEC): A Novel Versatile Player in Tumor Neovascularization and Cancer Metastasis

Hematogenous and lymphogenous cancer metastases are significantly impacted by tumor neovascularization, which predominantly consists of blood vessel-relevant angiogenesis, vasculogenesis, vasculogenic mimicry, and lymphatic vessel-related lymphangiogenesis. Among the endothelial cells that make up the lining of tumor vasculature, a majority of them are tumor-derived endothelial cells (TECs), exhibiting cytogenetic abnormalities of aneuploid chromosomes. Aneuploid TECs are generated from “cancerization of stromal endothelial cells” and “endothelialization of carcinoma cells” in the hypoxic tumor microenvironment. Both processes crucially engage the hypoxia-triggered epithelial-to-mesenchymal transition (EMT) and endothelial-to-mesenchymal transition (EndoMT). Compared to the cancerization process, endothelialization of cancer cells, which comprises the fusion of tumor cells with endothelial cells and transdifferentiation of cancer cells into TECs, is the dominant pathway. Tumor-derived endothelial cells, possessing the dual properties of cancerous malignancy and endothelial vascularization ability, are thus the endothelialized cancer cells. Circulating tumor-derived endothelial cells (CTECs) are TECs shed into the peripheral circulation. Aneuploid CD31⁺ CTECs, together with their counterpart CD31^- circulating tumor cells (CTCs), constitute a unique pair of cellular circulating tumor biomarkers. This review discusses a proposed cascaded framework that focuses on the origins of TECs and CTECs in the hypoxic tumor microenvironment and their clinical implications for tumorigenesis, neovascularization, disease progression, and cancer metastasis. Aneuploid CTECs, harboring hybridized properties of malignancy, vascularization and motility, may serve as a unique target for developing a novel metastasis blockade cancer therapy.

Endothelial cells in colorectal cancer

The dependence of tumor growth on neovascularization has become an important aspect of cancer biology. Tumor angiogenesis is one of the key mechanisms of tumorigenesis, growth and metastasis. The key events involved in this process are endothelial cell proliferation, migration, and vascular formation. Recent studies have revealed the importance of tumor-associated endothelial cells (TECs) in the development and progression of colorectal cancer (CRC), including epithelial proliferation, stem cell maintenance, angiogenesis, and immune remodeling. Decades of research have identified that the molecular basis of tumor angiogenesis includes vascular endothelial growth factors (VEGFs) and their receptor family, which are the main targets of antiangiogenesis therapy. VEGFs and their receptors play key roles in the pathology of angiogenesis, and their overexpression indicates poor prognosis in CRC. This article reviews the characteristics of the tumor vasculature and the role of TECs in different stages of CRC and immune remodeling. We also discuss the biological effects of VEGFs and their receptor family as angiogenesis regulators and emphasize the clinical implications of TECs in clinical treatment.

Selected by gene co-expression network and molecular docking analyses, ENMD-2076 is highly effective in glioblastoma-bearing rats

Background: Glioblastoma is the most common type of malignant brain tumor. Bioinformatics technology and structure biology were effectively and systematically used to identify specific targets in malignant tumors and screen potential drugs.

Results: GBM patients have higher AURKA and KDR mRNA expression compared with normal samples. Then, we identified a small molecular compound, ENMD-2076, could effectively inhibit Aurora kinase A and VEGFR-2 (encoded by KDR) activities. ENMD-2076 is predicted without toxic properties and also has absorption and gratifying brain/blood barrier penetration ability. Further results demonstrated that ENMD-2076 could significantly inhibit GBM cell lines proliferation and vitality, it also suppressed GBM cells migration and invasion. ENMD-2076 induced glioblastoma cell cycle arrest in G2-M phase and apoptosis by inhibiting PI3K/AKT/mTOR signaling pathways. Additionally, ENMD-2076 prolonged the median survival time of tumor-bearing rats and restrained growth rate of tumor volume in vivo.

Conclusions: Our findings reveal that ENMD-2076 is a promising drug in dealing with glioblastoma and have a perspective application.

Methods: We show that AURKA and KDR genes are hub driver genes in glioblastoma with bioinformatics technology including WGCNA analysis, PPI network, GO, KEGG analysis and GSEA analysis. After identifying a compound via virtual screening analysis, further experiments were carried out to examine the anti-glioblastoma activities of the compound in vivo and in vitro.

Apatinib suppresses breast cancer cells proliferation and invasion via angiomotin inhibition

Breast cancer is a leading cause of cancer-related death in the women worldwide. Apatinib is a novel tyrosine kinase inhibitor that selectively binds and inhibits vascular endothelial growth factor receptor 2 (VEGFR-2). The clinical trials have demonstrated the objective efficacy of Apatinib against metastatic breast cancer. However, the underlying mechanism is not well established. In the present study, the breast cell lines, BT-474 and MCF-7, were investigated. The effect of Apatinib on the cell viability was determined using CCK-8 assay. The migration, invasion, cell cycle distribution and the downstream signaling of VEGFR-2 in the cells were determined after 48 h treatment with this drug. Subsequently, Vector of angiomotin (AMOT) cDNA was transfected into MCF-7 cells. The cells were either exposed to Apatinib or vehicle and then examined for cell viabilities, migration, invasion, cell cycle distribution and the downstream signaling of VEGFR-2. Apatinib demonstrated a dose-dependent, significant inhibition of cell viabilities, migration and invasion of BT-474 and MCF-7 cells, with an increase in the percentage of cells in G1 phase and a decrease in S phase. In addition, in MCF-7 cells, Apatinib decreased AMOT expression, accompanied with the decreased expression of LATS1/2, YAP, ERK1/2 phosphorylation and cyclin D1. The inhibitory effect of Apatinib on the cell activities and protein expressions were significantly suppressed by AMOT overexpression. The results of this study indicated that Apatinib inhibited MCF-7 cell proliferation and invasion through AMOT/VEGFR-2 pathway.

Emodin suppresses growth and invasion of colorectal cancer cells by inhibiting VEGFR2

Emodin can effectively inhibit colorectal cancer cells, but the mechanism remains elusive. This study analyzed the changes of VEGFR2 signaling pathways in patients with colorectal cancer and the effects of emodin on HCT116 cells and xenograft tumor model. The expression levels of VEGFR2, PI3K, and p-AKT in colorectal cancer tissue samples were significantly higher than those in adjacent normal ones. Docking simulation confirmed that emodin bound the hydrophobic pocket and partially overlapped with the binding sites of VEGFR2, thus disrupting VEGFR2 dimerization. Western blotting further confirmed that emodin significantly inhibited the expression of VEGFR2, and reduced the expressions of PI3K and p-AKT in HCT116 cells. Furthermore, it suppressed the growth, adhesion and migration of HCT116 cells. In addition, emodin inhibited the tumor growth in xenograft model and the expressions of VEGFR2, PI3K and p-AKT in vivo. In conclusion, emodin suppressed the growth of colorectal cancer cells by inhibiting VEGFR2, as a potential candidate for therapy.

Hypoxia as a signal for prison breakout in cancer

PURPOSE OF REVIEW

We discuss recent discoveries in hypoxic cellular pathophysiology and explore the interplay between hypoxic malignant cells and other stromal elements. This review will provide an update on the effects of hypoxia on cancer outcomes and therapeutic resistance.

RECENT FINDINGS

Hypoxia has been discovered to be a key driver for tumor progression, both because of impacts on tumor cells and separately on the wider tumor microenvironment. The latter effects occur via epithelial mesenchymal transition, autophagy and metabolic switching. Through epithelial mesenchymal transition, hypoxia both drives metastasis and renders key target tissues receptive to metastasis. Autophagy is a double-edged sword which requires greater understanding to ascertain when it is a threat. Metabolic switching allows tumor cells to access hypoxic survival mechanisms even under normoxic conditions.Every element of the malignant stroma contributes to hypoxia-driven progression. Exosomal transfer of molecules from hypoxic tumor cells to target stromal cell types and the importance of microRNAs in intercellular communication have emerged as key themes.Antiangiogenic resistance can be caused by hypoxia-driven vasculogenic mimicry. Beyond this, hypoxia contributes to resistance to virtually all oncological treatment modalities.

SUMMARY

Recent advances have moved us closer to being able to exploit hypoxic mechanisms to overcome hypoxia-driven progression and therapy failure.

S100B Protein Stimulates Proliferation and Angiogenic Mediators Release through RAGE/pAkt/mTOR Pathway in Human Colon Adenocarcinoma Caco-2 Cells

Chronic inflammation and angiogenesis are associated with colonic carcinogenesis. Enteric glia-derived S100B protein has been proposed as an "ideal bridge", linking colonic inflammation and cancer, given its dual ability to up-regulate nuclear factor-kappaB (NF-κB) transcription via receptor for advanced glycation end products (RAGE) signaling and to sequestrate wild type pro-apoptotic wild type (wt)p53. However, its pro-angiogenic effects on cancer cells are still uninvestigated. To this aim, we evaluated the effect of exogenous S100B (0.05-5 µM) protein alone or in the presence of S100B blocking monoclonal antibody (mAb) (1:10⁵-1:10⁴ v/v diluted) on (1) cultured Caco-2 cells proliferation, migration and invasiveness in vitro, respectively by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT)-formazan, wound healing and matrigel invasion assays and (2) its effect on the release of pro-angiogenic factors, such as vascular endothelial growth factor (VEGF) by ELISA and immunofluorescence analyses. The effect of S100B alone or in the presence of S100BmAb was then investigated on RAGE/pAkt/mammalian target of rapamycin (mTOR) signaling pathway by immunoblot analysis. Our results showed that S100B markedly increases proliferation and invasiveness of Caco-2 cells, through the release of pro-angiogenic VEGF and NO paralleled to a significant decrease of wtp53 expression mediated by RAGE-p38 mitogen-activated protein kinase (MAPK)/pAkt-mTOR and hypoxia-inducible factor 1-alpha (HIF1α) pathways. Such effects were counteracted by S100BmAb, indicating that S100B targeting is a potential approach to inhibit colon carcinoma proliferation and angiogenesis.

Sp1 contributes to overexpression of stanniocalcin 2 through regulation of promoter activity in colon adenocarcinoma

BACKGROUND

Aberrant expression of stanniocalcin 2 (STC2) is implicated in colon adenocarcinoma (COAD). A previous study identified that STC2 functions as a tumor promoter to drive development of some cancers, but the role of its overexpression in the development of COAD remains unclear.

AIM

To evaluate the regulation mechanism of STC2 overexpression in COAD.

METHODS

The expression of STC2 in COAD was assessed by TCGA COAD database and GEO (GSE50760). Methylation level of the STC2 promoter was evaluated with beta value in UALCAN platform, and the correlation between STC2 expression and survival rate was investigated with TCGA COAD. Transcription binding site prediction was conducted by TRANSFAC and LASAGNA, and a luciferase reporter system was used to identify STC2 promoter activity in several cell lines, including HEK293T, NCM460, HT29, SW480, and HCT116. Western blotting was performed to evaluate the role of Sp1 on the expression of STC2.

RESULTS

The central finding of this work is that STC2 is overexpressed in COAD tissues and positively correlated with poor prognosis. Importantly, the binding site of the transcription factor Sp1 is widely located in the promoter region of STC2. A luciferase reporter system was successfully constructed to analyze the transcription activity of STC2, and knocking down the expression of Sp1 significantly inhibited the transcription activity of STC2. Furthermore, inhibition of Sp1 remarkably decreased protein levels of STC2.

CONCLUSION

Our data provide evidence that the transcription factor Sp1 is essential for the overexpression of STC2 in COAD through activation of promoter activity. Taken together, our finding provides new insights into the mechanism of oncogenic function of COAD by STC2.