Regulation of OCT2 transcriptional repression by histone acetylation in renal cell carcinoma

Renal cell carcinoma (RCC) is a common malignant tumour affecting the urinary system, and multidrug resistance is one of the major reasons why chemotherapy for this type of cancer often fails. Previous studies have shown that loss of the human organic cation transporter OCT2 is the main factor contributing to oxaliplatin resistance in RCC, and that DNA hypermethylation and histone methylation play important roles in the transcriptional repression of OCT2 in RCC. In this study, we found that histone acetylation also regulates OCT2 repression in RCC and elucidated the underlying mechanisms. In normal renal cells, HDAC7 combines with MYC at the OCT2 promoter, resulting in a decrease in free HDAC7, which in turn increases the levels of H3K18ac and H3K27ac at the OCT2 promotor and activates OCT2 expression. In RCC cells, however, the interaction between HDAC7 and MYC does not occur, which leads a high abundance of HDAC7 and low levels of H3K18ac and H3K27ac at the OCT2 promoter, thereby resulting in the inhibition of OCT2 transcription. We found that combined treatment using the DNA methylation inhibitor decitabine and the histone deacetylase inhibitor vorinostat significantly increased the expression of OCT2 in RCC cell lines, which sensitized these cells to oxaliplatin. We accordingly propose that the combination of anticancer agents and epigenetic drugs can provide a novel chemotherapeutic regimen.

Epirubicin-based compared with docetaxel-based chemotherapy for advanced gastric carcinoma: A systematic review and meta-analysis

Docetaxel or Epirubicin-based regimens are both approved for the treatment of metastatic gastric cancer. We perform a systemic review with metanalysis to evaluate the efficacy and toxicities of docetaxel-based chemotherapy compared with epirubicin-containing regimens. A metaanalysis of randomized studies in accordance with the preference guidelines for reported items in systematic reviews and meta-analyses is performed in which the databases of PubMed, the Cochrane Library, and the ASCO University Meeting were searched for relevant publications. The primary outcome was efficacy, the secondary toxicities. A total of 553 cases were included in the meta-analysis; 278 received epirubicin-based treatment and 313 received docetaxel. The pooled risk ratio to achieve an objective response and a disease control rate were 1.08 (95% CI 0.85-1.37; P=0.52) and 0.90 (95% CI 0.75-1.08; P=0.27) respectively. EPI arm showed a decrease in the risk of neutropenia, anemia, fatigue, asthenia and diarrhea, paraesthesia; docetaxel arm showed a decrease in the risk of leucopenia, thrombocytopenia, anorexia, nausea, nausea-vomiting, stomatitis and neutropenic fever. The results of our study suggest a similar activity of docetaxel and epirubicin-based chemotherapeutic regimens in metastatic gastric cancer. Other parameters as, comorbidity, concomitant diseases and prior therapies should be taken into account to address the clinician's choice in selecting the best therapeutical approach for any single patient.

Clinical research of intraperitoneal implantation of sustained-release 5-fluorouracil in advanced colorectal cancer

BACKGROUND

The objective of this study was to investigate the safety and long-term clinical effect of intraperitoneal implantation of sustained-release 5-fluorouracil in patients with advanced colorectal cancer during radical resection.

METHODS

A total of 202 patients with advanced colorectal cancer undergoing radical operations were randomly divided into an experimental group (98 cases, intraoperative intraperitoneal implantation of sustained-release 5-fluorouracil 600 mg as local chemotherapy) and a control group (104 cases, without local chemotherapy). The clinical data of the two groups was compared including toxicity, complications, local recurrence rate, distant metastasis, disease-free survival, and 1-, 3-, and 5-year survival rates.

RESULTS

Both groups of patients were followed up for more than 5 years, the longest follow-up time was 7.5 years. Bone marrow suppression, hepato-renal function, postoperative anastomotic leakage, pelvic effusion, incision infection, the incidence of intestinal obstruction, venting time, and hospital stay after operation (days) between two groups had no statistical significant difference. Locoregional recurrence and liver metastasis rate were decreased significantly in experimental group (P = 0.04 and 0.04). Extensive peritoneal metastasis and other organ metastasis rates had no significant difference between two groups. In the experimental group, 1-, 3-, and 5-year survival rates were higher than in the control group (95.92 vs 87.50 %, 77.55 vs 64.42 %, and 56.12 vs 40.38 %), which had significant difference. Disease-free survival (DFS) of the experimental group was higher than that of the control group (χ (2) = 5.00, P = 0.025).

CONCLUSIONS

Intraperitoneal implantation of sustained-release 5-fluorouracil is safe for advanced colorectal cancer during radical resection, which can reduce locoregional recurrence rate and liver metastasis rate. The long-term efficacy was reliable, and long-term survival and disease-free survival rate can be improved.

Neoadjuvant Therapy of DOF Regimen Plus Bevacizumab Can Increase Surgical Resection Ratein Locally Advanced Gastric Cancer: A Randomized, Controlled Study

Locally advanced gastric cancer (LAGC) is best treated with surgical resection. Bevacizumab in combination with chemotherapy has shown promising results in treating advanced gastric cancer. This study aimed to investigate the efficacy of neoadjuvant chemotherapy using the docetaxel/oxaliplatin/5-FU (DOF) regimen and bevacizumab in LAGC patients.Eighty LAGC patients were randomized to receive DOF alone (n = 40) or DOF plus bevacizumab (n = 40) as neoadjuvant therapy before surgery. The lesions were evaluated at baseline and during treatment. Circulating tumor cells (CTCs) were counted using the FISH test. Patients were followed up for 3 years to analyze the disease-free survival (DFS) and overall survival (OS).The total response rate was significantly higher in the DOF plus bevacizumab group than the DOF group (65% vs 42.5%, P = 0.0436). The addition of bevacizumab significantly increased the surgical resection rate and the R0 resection rate (P < 0.05). The DOF plus bevacizumab group showed significantly greater reduction in CTC counts after neoadjuvant therapy in comparison with the DOF group (P = 0.0335). Although the DOF plus bevacizumab group had significantly improved DFS than the DOF group (15.2 months vs 12.3 months, P = 0.013), the 2 groups did not differ significantly in OS (17.6 ± 1.8 months vs 16.4 ± 1.9 months, P = 0.776. Cox proportional model analysis showed that number of metastatic lymph nodes, CTC reduction, R0 resection, and neoadjuvant therapy are independent prognostic factors for patients with LAGC.Neoadjuvant of DOF regimen plus bevacizumab can improve the R0 resection rate and DFS in LAGC. These beneficial effects might be associated with the reduction in CTC counts.