Circular RNA circ_0006089 promotes the progression of gastric cancer by regulating the miR-143-3p/PTBP3 axis and PI3K/AKT signaling pathway.

OBJECTIVES: Circular RNAs (circRNAs) play pivotal roles in malignancies including gastric cancer (GC). We aimed to investigate the biological function and regulatory mechanism of circ_0006089 in GC. METHODS: Circ_0006089, microRNA (miR)-143-3p, and polypyrimidine tract-binding protein 3 (PTBP3) expressions were measured via quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) in GC cell lines. Cell proliferative capacity was determined by colony formation and CCK-8 assays. Flow cytometry was employed for measuring cell apoptosis. Cell invasion and migration were measured via transwell and wound-healing assays. Western blot analysis was utilized for detecting protein expressions of E-cadherin, N-cadherin, vimentin, PTBP3, PI3K, p-PI3K, AKT, and p-AKT. Dual-reporter luciferase analysis was conducted to confirm the association between miR-143-3p and circ_0006089 or PTBP3. The role of circ_0006089 in vivo was detected via establishing a mice xenograft model. RESULTS: Circ_0006089 expression was increased in GC. Circ_0006089 downregulation suppressed the proliferation and metastasis and induced apoptosis of GC cells, which was counteracted by miR-143-3p inhibition or PTBP3 overexpression. In addition, circ_0006089 overexpression could promote GC progression. MiR-143-3p specially bound to circ_0006089 and PTBP3 was targeted by miR-143-3p. Moreover, circ_0006089 could regulate PTBP3 expression and the PI3K/AKT pathway by sponging miR-143-3p. Circ_0006089 knockdown also suppressed tumor growth. CONCLUSION: Circ_0006089 regulated miR-143-3p/PTBP3/PI3K/AKT pathway to facilitate GC progression.

[Combined preoperative xeloda and radiotherapy for lower rectal cancer].

OBJECTIVE: To evaluate the effect of combined preoperative xeloda and pelvic radiotherapy on locally advanced lower rectal cancer. METHODS: Sixty lower rectal cancer patients were divided randomly into two groups. 30 patients (Group A) were treated with operation alone and 30 patients (Group B) were treated with xeloda and radiotherapy before operation. RESULTS: The operative resection, anal preservation and local recurrence rates were 86.66%, 33.33%, 15.38% in group A and 100%, 83.33%, 0% in group B (P < 0.05 and P < 0.01). CONCLUSION: Combined preoperative xeloda and radiotherapy for lower rectal cancer is able to significantly improve the operative resection, anal preservation and decrease the local recurrence rates.

[Efficacy evaluation of intersphincteric resection during anus-preserving operation for ultralow rectal carcinoma].

OBJECTIVE: To evaluate anorectal dynamics, function and efficacy of ultralow rectal carcinoma patients undergone intersphincteric resection(ISR). METHODS: From January 2004 to August 2007, 30 patients with ultralow rectal carcinoma(2.5-4.0 cm distance from anal edge) underwent ISR. All the patients received anorectal manometry before and after operation. The postoperative anal function was evaluated by Williams continence standard and the treatment outcome was followed up. RESULTS: After ISR operation, anal resting pressure, maximum squeeze pressure and maximum tolerance volume of the rectum decreased significantly (all P<0.01) and restored gradually, but not to normal. The rectal anal inhibitory reflex disappeared in 27 patients(90.0%) and was not improved. According to Williams continence standard, 86.7%, 93.3% and 96.7% of patients obtained acceptable anal function in 3, 6, and 12 months after operation respectively. During follow-up of 12 to 44 months, all the patients were still alive and no patient developed pelvis or local recurrence, distant metastasis and anastomotic leakage. Fecal eczema of anus occurred in 10 patients, colonic mucosa prolapse in 2 patients and stenosis of anal canal in one patient. CONCLUSION: ISR for ultralow rectal carcinoma can not only attain radical treatment outcome, but also preserve anal sphincter.

[Clinical significance of lymphatic vessel density in determining the length of distal resection in rectal cancer].

OBJECTIVE: To study the the relationship between lymphatic vessel density (LVD) and distal intramural spread (DIS), and evaluate the value of LVD in determining the length of distal resection in low rectal cancer. METHODS: Ninety-two samples from patients undergone curative resection of low rectal cancer were studied. DIS was detected by HE stain. LVD was examined by immunohisto-chemical LYVE-1 (lymphatic vessel endothelial hyaluronan receptor). The association of LVD with DIS and other clinicopathological factors were examined. RESULTS: DIS (range 0.1-2.4 cm, mean 0.31 cm) was present in 44(47.8%) patients with low rectal cancer, including 23(52.3%) cases with cancer emboli in lymphatic vessels. LVD of peritumoral lesion was significantly higher than that of intratumoral lesion. LVD of DIS subgroup was significantly higher than that of non-DIS subgroup. Positive correlation was found by rank correlation test between the length of DIS and the LVD at peritumor tissue in DIS group (n=44, r=0.755, P<0.01). LVD was also positively correlated with the infiltration extent, lymphatic invasion and lymph node metastasis. CONCLUSIONS: Lymphangiogenesis plays an important role in rectal cancer metastasis and cancer emboli in lymphatic vessels is the most common modality of DIS. The LVD is positively correlated with DIS, which may be helpful to determine the distal clearance length of rectal cancer.