Oridonin induces apoptosis and senescence in colorectal cancer cells by increasing histone hyperacetylation and regulation of p16, p21, p27 and c-myc

<p>Abstract</p> <p>Background</p> <p>Oridonin, a tetracycline diterpenoid compound, has the potential antitumor activities. Here, we evaluate the antitumor activity and action mechanisms of oridonin in colorectal cancer.</p> <p>Methods</p> <p>Effects of oridonin on cell proliferation were determined by using a CCK-8 Kit. Cell cycle distribution was determined by flow cytometry. Apoptosis was examined by analyzing subdiploid population and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay. Senescent cells were determined by senescence-associated β-galactosidase activity analysis. Semi-quantitative RT-PCR was used to examine the changes of mRNA of p16, p21, p27 and c-myc. The concomitant changes of protein expression were analyzed with Western blot. Expression of AcH3 and AcH4 were examined by immunofluorescence staining and Western blots. Effects of oridonin on colony formation of SW1116 were examined by Soft Agar assay. The in vivo efficacy of oridonin was detected using a xenograft colorectal cancer model in nude mice.</p> <p>Results</p> <p>Oridonin induced potent growth inhibition, cell cycle arrest, apoptosis, senescence and colony-forming inhibition in three colorectal cancer cell lines in a dose-dependent manner in vitro. Daily i.p. injection of oridonin (6.25, 12.5 or 25 mg/kg) for 28 days significantly inhibited the growth of SW1116 s.c. xenografts in BABL/C nude mice. With western blot and reverse transcription-PCR, we further showed that the antitumor activities of oridonin correlated with induction of histone (H3 and H4) hyperacetylation, activation of p21, p27 and p16, and suppression of c-myc expression.</p> <p>Conclusion</p> <p>Oridonin possesses potent in vitro and in vivo anti-colorectal cancer activities that correlated with induction of histone hyperacetylation and regulation of pathways critical for maintaining growth inhibition and cell cycle arrest. Therefore, oridonin may represent a novel therapeutic option in colorectal cancer treatment.</p

Integrating Chemotherapy into the Management of Oligometastatic Colorectal Cancer: Evidence-Based Approach Using Clinical Trial Findings

PURPOSE: With the use of case presentations, we present a review of the role of systemic chemotherapy in oligometastatic colorectal cancer and suggest ways to integrate clinical research findings into the interdisciplinary management of this potentially curable subset of patients. METHODS: This educational review discusses the role of chemotherapy in the management of oligometastatic metastatic colorectal cancer. RESULTS: In initially resectable oligometastatic colorectal cancer, the goal of chemotherapy is to eradicate micrometastatic disease. Perioperative 5-fluorouracil and oxaliplatin along with surgical resection can result in 5-year survival rates as high as 57%. With the development of increasingly successful chemotherapy regimens, attention is being paid to the use of chemotherapy to convert patients with initially unresectable metastasis into patients with a chance of surgical cure. The choice of chemotherapy regimen requires consideration of the goals of therapy and assessment of both tumor and patient-specific factors. DISCUSSION: Herein we discuss the choice and timing of chemotherapy in patients with initially resectable and borderline resectable metastatic colorectal cancer. Coordinated multidisciplinary care of such patients can optimize survival outcomes and result in the cure of patients with this otherwise lethal disease