Chemotherapeutic and antiangiogenic drugs beyond tumor progression in colon cancer: Evaluation of the effects of switched schedules and related pharmacodynamics

Novel biomarkers used for early diagnosis and tyrosine kinase inhibitors as targeted therapies in colorectal cancer

Colorectal cancer (CRC) is the third most common and second most lethal type of cancer worldwide, presenting major health risks as well as economic costs to both people and society. CRC survival chances are significantly higher if the cancer is diagnosed and treated early. With the development of molecular biology, numerous initiatives have been undertaken to identify novel biomarkers for the early diagnosis of CRC. Pathological disorders can be diagnosed at a lower cost with the help of biomarkers, which can be detected in stool, blood, and tissue samples. Several lines of evidence suggest that the gut microbiota could be used as a biomarker for CRC screening and treatment. CRC treatment choices include surgical resection, chemotherapy, immunotherapy, gene therapy, and combination therapies. Targeted therapies are a relatively new and promising modality of treatment that has been shown to increase patients' overall survival (OS) rates and can inhibit cancer cell development. Several small-molecule tyrosine kinase inhibitors (TKIs) are being investigated as potential treatments due to our increasing awareness of CRC's molecular causes and oncogenic signaling. These compounds may inhibit critical enzymes in controlling signaling pathways, which are crucial for CRC cells' development, differentiation, proliferation, and survival. On the other hand, only one of the approximately 42 TKIs that demonstrated anti-tumor effects in pre-clinical studies has been licensed for clinical usage in CRC. A significant knowledge gap exists when bringing these tailored medicines into the clinic. As a result, the emphasis of this review is placed on recently discovered biomarkers for early diagnosis as well as tyrosine kinase inhibitors as possible therapy options for CRC.

Tumor Microenvironment as a Therapeutic Target in Melanoma Treatment

The role of the tumor microenvironment in tumor growth and therapy has recently attracted more attention in research and drug development. The ability of the microenvironment to trigger tumor maintenance, progression, and resistance is the main cause for treatment failure and tumor relapse. Accumulated evidence indicates that the maintenance and progression of tumor cells is determined by components of the microenvironment, which include stromal cells (endothelial cells, fibroblasts, mesenchymal stem cells, and immune cells), extracellular matrix (ECM), and soluble molecules (chemokines, cytokines, growth factors, and extracellular vesicles). As a solid tumor, melanoma is not only a tumor mass of monolithic tumor cells, but it also contains supporting stroma, ECM, and soluble molecules. Melanoma cells are continuously in interaction with the components of the microenvironment. In the present review, we focus on the role of the tumor microenvironment components in the modulation of tumor progression and treatment resistance as well as the impact of the tumor microenvironment as a therapeutic target in melanoma.

Multilayered polymer coating modulates mucoadhesive and biological properties of camptothecin-loaded lipid nanocapsules

Lipid core nanocapsules (NCs) coated with multiple polymer layers were rationally designed as a potential approach for the colonic delivery of camptothecin (CPT). Chitosan (CS), hyaluronic acid (HA) and hypromellose phthalate (HP) were selected as coating materials, to modulate the mucoadhesive and permeability properties of CPT regarding the improvement of local and targeted action in the colon cancer cells. NCs were prepared by emulsification/solvent evaporation method and coated with multiple polymer layers by polyelectrolyte complexation technique. NCs exhibited spherical shape, negative zeta potential, and size ranged from 184 to 252 nm. The high efficiency of CPT incorporation (>94%) was evidenced. The ex vivo permeation assay showed that nanoencapsulation reduced the permeation rate of CPT through the intestinal mucosa by up to 3.5 times, and coating with HA and HP reduced the permeation percentage by 2 times when compared to NCs coated only with CS. The mucoadhesive capacity of NCs was demonstrated in gastric and enteric pH. Nanoencapsulation did not reduce the antiangiogenic activity of CPT and, additionally, it was observed that nanoencapsulation resulted in localized antiangiogenic action of CPT.

Synthesis, physicochemical characterization, and in vitro evaluation of biodegradable PLGA nanoparticles entrapped to folic acid for targeted delivery of kaempferitrin

Polymeric nanoparticles are widely studied in the treatment of colorectal cancer. Kaempferitrin-loaded nontoxic and biodegradable poly(d,l-lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) developed by the solvent emulsion evaporation method by improving its solubility and bioavailability. In order to improve the delivery of kaempferitrin (KM) to cancerous cells, folic acid (FA) combined kaempfertrin PLGA NPs were prepared. The goal of the study was whether PLGA NPs with surface KM and FA could help to prevent colorectal cancer. The synthesis of KM with FA in a nanomedicine could be crucial in the development of colon cancer chemotherapeutics. The physicochemical characteristics of synthesized KM-entrapped PLGA NPs were investigated by XRD, FTIR, zeta potential, and TEM. The KM + FA + PLGA NPs showed particle size with 132.9 ± 1.4 nm, zeta potential -15.0 ± 1.73 mV, encapsulation efficiency 67.92 ± 4.8, and drug-loading capacity 0.463 ± 0.173. In vitro cytotoxicity study on HT-29 cell lines using the MTT assay, the apoptotic study revealed that KM + FA + PLGA NPs have an enhanced cytotoxic effect compared to the KM + PLGA NPs drug solution. These findings suggested that KM + FA + PLGA NPs could be an effective chemotherapeutic drug delivery system in colon adenocarcinoma HT-29 cells.

Management of acute kidney injury in gastrointestinal tumor: An overview

Gastrointestinal tumors remain a global health problem. Acute kidney injury (AKI) is a common complication during the treatment of gastrointestinal tumors. AKI can cause a decrease in the remission rate and an increase in mortality. In this review, we analyzed the causes and risk factors for AKI in gastrointestinal tumor patients. The possible mechanisms of AKI were divided into three groups: pretreatment, intrafraction and post-treatment causes. Treatment and prevention measures were proposed according to various factors to provide guidance to clinicians and oncologists that can reduce the incidence of AKI and improve the quality of life and survival rate of gastrointestinal tumor patients.

Changes and Prognostic Value of lncRNA CASC9 in Patients with Advanced Colon Cancer after Chemotherapy

OBJECTIVE

Colon cancer (CC) shows a gradual increasing incidence in recent years, and chemotherapy is a frequently adopted treatment for patients with middle or advanced colon cancer (ACC), but it lacks prognostic markers after CC.

METHODS

The changes of lncRNA CASC9 in 58 patients with CC were determined using a real-time quantitative PCR (qRT-PCR) assay before and after chemotherapy, and the correlation of serum lncRNA CASC9 with efficacy of FOLFOX4 regimen (oxaliplatin + calcium folinate + fluorouracil) was analyzed. The patients were followed up to understand the association of lncRNA CASC9 with overall survival (OS) and progression-free survival (PFS).

RESULTS

Patients with CC showed notably higher lncRNA CASC9 expression than controls, and lncRNA CASC9 presented an association with the clinical stage of the patients. In addition, lncRNA CASC9 demonstrated a clinical value in predicting efficacy on patients and acted as one independent prognostic factor for PFS in patients with ACC.

CONCLUSIONS

With increased expression of serum lncRNA CASC9, patients with ACC suffered an unfavorable chemotherapy effect. In addition, serum lncRNA CASC9 is a promising sensitive indicator for prediction of ACC and is related to the clinical efficacy and prognosis of patients.

Active metronomic vinorelbine schedules decrease plasma interleukin-2 levels in mice with Lewis lung carcinoma

The aim of our study was to investigate the effects of metronomic vinorelbine (mVNR) in a tumor model of Lewis Lung (LL) cancer in immunocompetent C57BL/6 mice, looking at the plasma levels of interleukin-2 (IL-2) and interleukin-8 (IL-8). mVNR caused a concentration-dependent antiproliferative effect in vitro on LL/2 cells. The in vivo experiment showed the significant antitumor effects of mVNR at the dose of 4 mg/Kg and 5 mg/Kg, 3 times/week, and the significant dose-dependent decrease of IL-2 concentrations in plasma samples. Conversely, such an effect was not observed for IL-8. A significant decrease in microvessel density was also found at both the active mVNR doses. In conclusion, our study confirmed the activity of mVNR in an immunocompetent model of lung carcinoma and suggest multiple mechanisms of action, including the modulation of IL-2 levels.

sATP‑binding cassette subfamily G member 2 enhances the multidrug resistance properties of human nasal natural killer/T cell lymphoma side population cells

Extranodal natural killer (NK)/T cell lymphoma, nasal type (ENKL) is a rare type of non-Hodgkin's lymphoma that is associated with limited effective treatment options and unfavorable survival rate, which is partly the result of multidrug resistance (MDR). The presence of side population (SP) cells-SNK-6/ADM-SP (SSP) cells has been previously used to explore mechanisms of drug resistance. ATP-binding cassette subfamily G member 2 (ABCG2) is a gene involved in MDR and is closely associated with SPs. However, the function of ABCG2 in SSP cells is unclear. The present study verified the high expression of ABCG2 in SSP cells. The IC₅₀ values of doxorubicin, cytarabine, cisplatin, gemcitabine and l-asparaginase were tested to evaluate drug sensitivity in SSP cells with different levels of ABCG2 expression. ABCG2 was identified as a gene promoting in MDR. ABCG2 upregulated cell proliferation, increased clonogenicity, increased invasive ability and decreased apoptosis, in vivo and in vitro, when cells were treated with gemcitabine. To conclude, ABCG2 enhanced MDR and increased the typical biological characteristics associated with cancer cells in SP cells. With further investigation of the ABCG2 gene could have the potential to reverse MDR in ENKL.

Pharmacological effects of vinorelbine in combination with lenvatinib in anaplastic thyroid cancer

Anaplastic thyroid cancer (ATC) is a rare neoplasia with a poor prognosis. Proliferation and apoptosis assays were performed on ATC cell lines (8305C, 8505C) exposed to vinorelbine, lenvatinib, as well as to concomitant combinations. ABCB1, ABCG2 and CSF-1 mRNA expression was evaluated by real time PCR. The relative levels of pospho Akt were investigated as part of a human phospho-kinase array analysis, and CSF-1 and VEGFR-2 protein levels were measured by ELISA. The intracellular concentration of lenvatinib in ATC cells was measured by combined reversed-phase liquid chromatography-tandem mass spectrometry. An ATC subcutaneous xenograft tumor model in nude mice was treated with vinorelbine, lenvatinib, or vinorelbine plus lenvatinib. After treatment with vinorelbine, lenvatinib, a significant antiproliferative effect in ATC cell lines was observed. The concomitant treatment of vinorelbine and lenvatinib revealed synergism for all the fractions of affected cells. A decrease in ABCB1 expression was reported in both ATC cell lines treated with the lenvatinib plus vinorelbine combination, as was an increase in the intracellular concentration of lenvatinib. The combination caused a decrease in Akt, GSK3α/β, PRAS40 and Src phosphorylation, and in both CSF-1 mRNA and protein levels. In the subcutaneous tumor model, the combination reduced the tumor volume during the treatment period. Our results establish the synergistic ATC antitumor activity of a vinorelbine and lenvatinib combination.

Role of Extracellular Matrix in Gastrointestinal Cancer-Associated Angiogenesis

Gastrointestinal tumors are responsible for more cancer-related fatalities than any other type of tumors, and colorectal and gastric malignancies account for a large part of these diseases. Thus, there is an urgent need to develop new therapeutic approaches to improve the patients' outcome and the tumor microenvironment is a promising arena for the development of such treatments. In fact, the nature of the microenvironment in the different gastrointestinal tracts may significantly influence not only tumor development but also the therapy response. In particular, an important microenvironmental component and a potential therapeutic target is the vasculature. In this context, the extracellular matrix is a key component exerting an active effect in all the hallmarks of cancer, including angiogenesis. Here, we summarized the current knowledge on the role of extracellular matrix in affecting endothelial cell function and intratumoral vascularization in the context of colorectal and gastric cancer. The extracellular matrix acts both directly on endothelial cells and indirectly through its remodeling and the consequent release of growth factors. We envision that a deeper understanding of the role of extracellular matrix and of its remodeling during cancer progression is of chief importance for the development of new, more efficacious, targeted therapies.

Revision of the Regioselectivity of the Beirut Reaction of Monosubstituted Benzofuroxans with Benzoylacetonitrile. 6-Substituted quinoxaline-2-carbonitrile 1,4- dioxides: Structural Characterization and Estimation of Anticancer Activity and Hypoxia Selectivity

BACKGROUND

Quinoxaline 1,4-dioxides have a broad range of biological activity that causes a growing interest in their derivatives for drug discovery. Recent studies demonstrated that quinoxaline 1,4- dioxides have a promising anticancer activity and good hypoxia-selectivity.

OBJECTIVE

The preparation, isolation, structure characterization, and screening for anticancer activity of the first representatives of 6-substituted quinoxaline-2-carbonitrile 1,4-dioxides have been described.

MATERIALS AND METHODS

A series of 7- and 6-halogeno-3-phenylquinoxaline-2-carbonitrile 1,4-dioxides was synthesized by the Beirut reaction. The cytotoxicity was assessed by MTT test (72 h incubation) in normoxia (21% O2) and hypoxia (1% O2) conditions.

RESULTS

We found that during the Beirut reaction between a benzofuroxan bearing an electron withdrawing group and benzoylacetonitrile in the presence of triethylamine, in addition to well-known 7-substituted quinoxaline-2-carbonitrile 1,4-dioxides 7-11a, the 6-isomers 7-11b are formed. Moreover, the yield of the 6- isomers increased with the increase in the electron-withdrawing character of the substituent. For benzofuroxans with CO2Me and CF3 groups, 6-substituted quinoxaline-2-carbonitrile 1,4-dioxides 10-11b were the major products. Despite similarities in physicochemical and spectroscopic properties, the obtained isomers exhibit considerable differences in their anticancer activity and hypoxia selectivity.

CONCLUSION

Substituents and their electronic effects play a key role in the formation of 7- and 6-substituted quinoxaline-2-carbonitrile 1,4-dioxides in the Beirut reaction and in the cytotoxicity properties of the obtained isomers.