Pharmacogenetics of anticancer drug sensitivity and toxicity in colorectal cancer

Inter-individual differences in drug response are an important cause of failure in anticancer treatment and adverse drug events in cancer patients. Gene polymorphisms related to these outcomes have been investigated in an effort to find new genetic biomarkers to predict toxicity and response to anticancer drugs. Evaluating the value single nucleotide polymorphisms (SNPs) in the genes involved in transportation, activation and metabolism of anticancer drugs provides a promising approach to select the appropriate therapeutic regimes with at least adverse reactions. This review summarizes the current knowledge about the relationship between of SNPs involved in the transportation, activation and metabolism of anticancer drugs and treatment outcomes in colorectal cancer (CRC) patients

Crocin synergistically enhances the anti-proliferative activity of 5-FU through Wnt/PI3K pathway in a mouse model of colitis-associated colorectal cancer

Colorectal-cancer (CRC) is the third most common cause of cancer-related-death, and hence there is a need for the identification of novel-agents to improve the efficacy of existing-therapies. There is growing evidence for the anti-tumor-activity of crocin, although its activity and molecular-mechanisms in CRC remains to be elucidated. Here we explored the therapeutic-application of crocin or its combination with 5-Flurouracil in a mouse-model of colitis-associated colon-cancer. The anti-proliferative-activity of crocin was assessed in 2- and 3-dimensional cell-culture-models. The migratory-behaviors were determined, while the expression-levels of several-genes were assessed by qRT-PCR/Western-blotting. We examined the anti-inflammatory properties of crocin by pathological-evaluation and disease-activity-index as well as oxidative/ antioxidant markers: malondialdehyde (MDA) and total-thiols (T-SH) levels and superoxide-dismutase (SOD) and catalase (CAT) activity. Crocin suppressed cell-growth and the invasive-behavior of CRC-cells through modulation of the Wnt-pathway and E-cadherin. Moreover, administration of crocin alone, or in combination with 5-FU dramatically reduced the tumor-number and tumor-size in both distal/mid-colon followed by reduction in disease-activity-index. Crocin also suppressed the colonic-inflammation induced by Dextran-sulfate-sodium and notably recovered the increased-levels of MDA, decreased Thiol-levels and activity of CAT-levels. Crocin was able to ameliorate the severe-inflammation with mucosal-ulcers and high grade-dysplastic-crypts as detected by inflammation-score, Crypt-loss, pathological-changes and histology-scores. We demonstrated an antitumor-activity of crocin in CRC and its potential role in improvement of inflammation with mucosal ulcers and high grade dysplastic crypts, supporting the desireability of further investigations on the therapeutic potential of this approach in CRC

Rigosertib elicits potent anti-tumor responses in colorectal cancer by inhibiting Ras signaling pathway

Background: The therapeutic potency of Rigosertib (RGS) in the treatment of the myelodysplastic syndrome has been investigated previously, but little is known about its mechanisms of action. Methods: The present study integrates systems and molecular biology approaches to investigate the mechanisms of the anti-tumor effects of RGS, either alone or in combination with 5-FU in cellular and animal models of colorectal cancer (CRC). Results: The effects of RGS were more pronounced in dedifferentiated CRC cell types, compared to cell types that were epithelial-like. RGS inhibited cell proliferation and cell cycle progression in a cell-type specific manner, and that was dependent on the presence of mutations in KRAS, or its down-stream effectors. RGS increased both early and late apoptosis, by regulating the expression of p53, BAX and MDM2 in tumor model. We also found that RGS induced cell senescence in tumor tissues by increasing ROS generation, and impairing oxidant/anti-oxidant balance. RGS also inhibited angiogenesis and metastatic behavior of CRC cells, by regulating the expression of CD31, E-cadherin, and matrix metalloproteinases-2 and 9. Conclusion: Our findings support the therapeutic potential of this potent RAS signaling inhibitor either alone or in combination with standard regimens for the management of patients with CRC.Peer reviewe

Angiotensin receptor blocker losartan inhibits tumor growth of colorectal cancer

The renin-angiotensin system (RAS) is up-regulated in patients with colorectal cancer (CRC) and is reported to be associated with poor prognosis and chemo-resistance. Here we explored the therapeutic potential of targeting RAS in CRC using Losartan, an angiotensin receptor blocker. An integrative-systems biology approach was used to explore a proteome-level dataset of a gene signature that is modulated by Losartan. The anti-proliferative activity of Losartan was evaluated using 2- and 3-dimensional cell culture models. A xenograft model of colon cancer was used to investigate tumor growth with Losartan alone and in combination with 5-FU followed by histological staining (Hematoxylin & Eosin and Masson trichrome staining), biochemical analyses, gene expression analyses by RT-PCR, western blot/IHC, or MMP Gelatin Zymography studies. Effects on cell cycle and cell death were assessed by flow cytometry. Losartan inhibited cell growth and suppressed cell cycle progression, causing an increase in CRC cells in the G1 phase. Losartan significantly reduced tumor growth and enhanced tumor cell necrosis. An impact on the inflammatory response, including up-regulation of pro-inflammatory cytokines and chemokines in CRC cells are potential mechanisms that could partially explain Losartan’s anti-proliferative effects. Moreover, metastasis and angiogenesis were reduced in Losartan-treated mice as observed by inhibited matrix metalloproteinase-2 and -9 activities and decreased tumor vasculature. These data demonstrate the therapeutic potential of combining chemotherapeutic regimens with Losartan to synergistically enhance its activity and target the renin-angiotensin system as a new approach in colorectal cancer treatment

The hepatoprotective effects of fennel seeds extract and trans-Anethole in streptozotocin-induced liver injury in rats

Hypoglycemic, anti-inflammatory, and antioxidant activities of fennel have been recorded in numerous investigations. The study aimed to evaluate the protective effects of fennel or its active component trans-Anethole (TA) on streptozotocin-induced liver injury in rats. Rats were injected with a single dose of STZ (65 mg/kg) and treated with fennel (200 and 400 mg/kg), TA (80 mg/kg), or metformin (300 mg/kg) for 35 days. Serum lipid profile and liver enzyme activity (aminotransferases), oxidative stress markers, and the degree of fibrosis in the liver tissue were assessed. Both fennel and TA decreased blood glucose levels, reduced liver enzyme activity, food, and water intake, and intensity of weight loss, reduced serum triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), and increased high-density lipoprotein cholesterol (HDL-c). Additionally, fennel and TA significantly reduced MDA concentration while increased CAT activity and thiol content and reduced the degree of injury and fibrosis in the liver of diabetic rats. Our results suggest that fennel seed extract and its active compound TA are able to protect the liver against diabetes-induced hepatic injury in rats, probably via hypoglycemic and antioxidant effects

Inhibition of the Wnt/b-catenin pathway using PNU-74654 reduces tumor growth in in vitro and in vivo models of colorectal cancer

Background Colorectal-cancer (CRC) is amongst the most lethal-cancers, mainly due to its metastatic spread and drug chemoresistance. Hence there is a need for new approaches to either increase the efficacy of current therapy or introduce new therapies that have greater efficacy. There is increasing evidence that dysregulation of WNT-signaling-pathway plays an essential role in the development and prognosis of CRC. Here we have investigated the therapeutic potential of targeting the WNT/b-catenin pathway using a novel Wnt/b-catenin inhibitor, PNU-74654, in combination with 5-FU in CRC. Methods The anti-proliferative-effect of PNU-74654 was evaluated in two-/three-dimensional cell models. The activity of agents on cell growth, migration, invasion, cell cycle and apoptosis was evaluated by MTT, wound healing assay, invasion, FACS, and annexin V staining, respectively. The oxidant/antioxidant levels were also assessed by determining the level of MDA, SOD, as well as using the DCFH-DA assay. We used a xenograft model of CRC to investigate PNU-74654 activity alone and in combination with 5-FU follow by histological staining and biochemical and gene expression analyses by RT-PCR and western blot. Results PNU-74654 inhibited cell-growth and synergistically affected the anti-tumor properties of 5-FU via modulation of Cyclin D1 and survivin. This agent inhibited the migration/invasion of colorectal cancer cells via perturbation of E-cadherin. Furthermore, PNU-74654 inhibited the tumor growth, which was more pronounced using the PNU-74654 plus 5-FU combination via induction of reactive oxygen species, down-regulation of SOD and modulation of MCP-1, P53, TNF-α. Conclusions Our finding demonstrated that PNU-74654 can target Wnt-pathway, interfere with cell-proliferation, induced-cell death, reduced-migration and interact with 5-FU, supporting further investigations on this therapeutic-approach for colorectal cancer