Implantation metastasis from sigmoid colon cancer to rectal anastomosis proved by whole exome sequencing and lineage inference for cancer heterogeneity and evolution analysis: Case report and literature review.

It was estimated that 70% of patients with colorectal cancer were found to have viable exfoliated malignant cells in adjacent intestinal lumen. Exfoliated malignant cells had been reported to implant on raw surfaces, such as polypectomy site, anal fissure, anal fistula, hemorrhoidectomy wound, and anastomotic suture line. Tumors at anastomosis could be classified into four groups: local recurrence, local manifestation of widespread metastasis, metachronous carcinogenesis, and implantation metastasis. However, all of the previous studies only reported the phenomena of implantation metastasis at anastomosis. No study had proved the origin of anastomotic metastasis by genomic analysis. In this study, a 43-year-old woman presented with persistent hematochezia was diagnosed as having severe mixed hemorrhoids. She was treated by procedure for prolapse and hemorrhoids (PPH), without receiving preoperative colonoscopy. Two months later, she was found to have sigmoid colon cancer by colonoscopy due to continuous hematochezia and received radical sigmoidectomy. Postoperative histological examination confirmed the lesion to be a moderately differentiated adenocarcinoma (pT3N1M0). Six months later, she presented with hematochezia again and colonoscopy revealed two tumors at the rectal anastomosis of PPH. Both tumors were confirmed to be moderately differentiated adenocarcinoma without lymph node and distant metastasis and were finally removed by transanal endoscopic microsurgery (TEM). Pathological examination, whole exome sequencing (WES), and Lineage Inference for Cancer Heterogeneity and Evolution (LICHeE) analysis demonstrated that the two tumors at the rectal anastomosis were probably implantation metastases arising from the previous sigmoid colon cancer. This is the first study to prove implantation metastasis from colon cancer to a distal anastomosis by WES and LICHeE analysis. Therefore, it is recommended to rule out colorectal cancer in proximal large bowel before performing surgery with a rectal anastomosis, such as PPH and anterior resection. For patients with a suspected implanted tumor, WES and LICHeE could be used to differentiate implantation metastasis from metachronous carcinogenesis.

Significance of neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, lymphocyte-to-monocyte ratio and prognostic nutritional index for predicting clinical outcomes in T1-2 rectal cancer.

BACKGROUND: Inflammation-related parameters have been revealed to have prognostic value in multiple caners. However, the significance of some inflammation-related parameters, including the peripheral blood neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR) and prognostic nutritional index (PNI), remains controversial in T1-2 rectal cancer (RC). METHODS: Clinical data of 154 T1-2 RC patients were retrospectively reviewed. The cut-off values for NLR, PLR, LMR, and PNI were determined by receiver operating characteristic curves. The relationships of these parameters with postoperative morbidities and prognosis were statistically analysed. RESULTS: The optimal cut-off values for preoperative NLR, PLR, LMR and PNI were 2.8, 140.0, 3.9, and 47.1, respectively. Significant but heterogeneous associations were found between NLR, PLR, LMR and PNI and clinicopathological factors. In addition, high NLR, high PLR, and low PNI were correlated with an increased postoperative morbidity rate. Patients with high NLR/PLR or low LMR/PNI had lower OS and DFS rates. On multivariate analysis, only high NLR was identified as an independent risk factor for poor DFS. CONCLUSIONS: NLR, PLR, and PNI are valuable factors for predicting postoperative complications in T1-2 RC patients. A preoperative NLR of more than 2.8 is an independent prognostic factor for poor DFS in T1-2 RC patients.

MicroRNA-17 induces epithelial-mesenchymal transition consistent with the cancer stem cell phenotype by regulating CYP7B1 expression in colon cancer.

MicroRNA-17 (miRNA-17/miR­17) expression has been confirmed to be significantly higher in colorectal cancer tissues than in normal tissues. However, its exact role in colorectal cancer has not yet been fully elucidated. In this study, we found that miR-17 not only promoted epithelial-mesenchymal transition (EMT), but also promoted the formation of a stem cell-like population in colon cancer DLD1 cells. We also wished to determine the role of cytochrome P450, family 7, subfamily B, polypeptide 1 (CYP7B1) in CRC. miR-17 was overexpressed using a recombinant plasmid and CYP7B1 was silenced by transfection with shRNA. Western blot analysis was used to determine protein expression in the DLD1 cells and in tumor tissues obtained from patients with colon cancer. Our results revealed that miR­17 overexpression led to the degradation of CYP7B1 mRNA expression in DLD1 cells. In addition, we found that the silencing of CYB7B1 promoted EMT and the formation of a stem cell-like population in the cells. Thus, our findings demonstrate that miR­17 induces EMT consistent with the cancer stem cell phenotype by regulating CYP7B1 expression in colon cancer.

Lipoxin A4 ameliorates ischemia/reperfusion induced spinal cord injury in rabbit model.

Ischemia/reperfusion (I/R) induced spinal cord injury is an important pathologic mechanism leading to the paraplegia observed after surgery to repairaortic aneurysms. This study aims to investigate the neuroprotective effects of Lipoxin A4 and its potential mechanism in a rabbit model with I/R spinal cord injury. Forty-five rabbits were randomly divided into three groups: sham group, I/R group and Lipoxin A4 group. Rabbits were subject to 30 min aortic occlusion to induce transient spinal cord ischemia. All animals were sacrificed after neurological evaluation with modified Tarlov criteria at the 48th hour after reperfusion, and the spinal cord segments (L4-6) were harvested for histopathological examination, as well as local malondialdehyde (MDA) and total superoxide dismutase (SOD) activity analysis. All animals in the I/R group became paraplegic. While after 48-hour treatment, compared with I/R group, Lipoxin A4 significantly improved neurological function, reduced cell apoptosis and MDA levels as well as increased SOD activity (P < 0.05). These results suggest that Lipoxin A4 can ameliorate I/R induced spinal cord injury in Rabbit through its antiapoptosis and antioxidant activity.

[Effect of n-3 polyunsaturated fatty acids on proliferation and apoptosis of human colon cancer cell].

OBJECTIVE: To investigate the effects of n-3 polyunsaturated fatty acids(n-3PUFA) on human colorectal cancer cell line HT-29 and associated mechanism. METHODS: The effects of docosahexaenoic acid (DHA) on the proliferation and apoptosis on HT-29 human colorectal cancer cells were evaluated by MTT assay, cell morphology (Hoechst33258 dyeing), DNA gel electrophoresis, and flow cytometry. The content of n-6PUFA and n-3PUFA of the treated cells and the ratio of n-6/n-3PUFA were analyzed by chromatography. RESULTS: DHA effectively inhibited HT-29 cell proliferation in a dose- and time-dependent manner. The proliferative inhibition rates of HT-29 cells treated with 10, 20, 40, and 80 mg/L DHA for 24 hours were 16.8%, 24.7%, 50.0%, and 60.1%, respectively, while the inhibition rates were 50.0%, 69.9%, and 77.0% respectively when HT-29 cells were treated with 40 mg/L DHA for 24, 48, and 72 hours. The typical apoptotic morphologic changes of HT-29 cells could be observed, including chromatin margination, nuclear condensation and apoptotic bodies. Gel electrophoresis of DNA degradation displayed typical DNA ladder fragments. HT-29 cells treated with DHA were arrested in G1 phase and the proportion of HT-29 cells in Gl phase increased compared with that of the control group (72.1% vs. 51.3%) while the proportion of the cells in S phase decreased significantly (19.9% vs. 38.9%). The content of n-6PUFA decreased, n-3PUFA content increased and the ratio of n-6/n-3PUFA lowered significantly in colorectal cancer cells treated with DHA (P<0.01). CONCLUSIONS: n-3PUFA can inhibit the growth of human colorectal cancer cells via inhibition of the proliferation and induction of apoptosis. These effects may be associated with decrease in n-6/n-3PUFA ratio.

[Outcomes after transanal endoscopic microsurgery for early rectal cancer and risk factors associated with recurrence].

OBJECTIVE: To investigate outcomes after transanal endoscopic microsurgery (TEM) for early rectal cancer, identify risk factors associated with recurrence, and explore the indication of TEM for rectal cancer. METHODS: Sixty patients with rectal cancer undergoing TEM between June 2006 and June 2009 in the Provincial Qianfoshan Hospital of Shandong University were included in this study and data were retrospectively analyzed. RESULTS: There were 12 patients with pTis rectal cancer, 38 with pT1 and 10 with pT2. All the lesions were excised en bloc by full-thickness TEM. No positive resection margins were reported. The operative time was(65.0 ± 36.5) min. Estimated blood loss was (10.5 ± 5.8) ml and hospital stay was(4.5 ± 2.7) d. No perioperative mortality and complications occurred. The median follow-up was 28.5(range, 12-48) months. No recurrence developed in pTis lesions. There was significant difference in local recurrence rate between pT1 and pT2(2.6% vs. 40.0%, P<0.05). The recurrence rate in lesions larger than 3 cm in diameter(19.0%, 4/21) was significantly higher than that in lesions smaller than 3 cm in diameter (2.6%, 1/39) (P<0.05). Multivariate analysis showed that depth of tumour invasion(T stage) and tumour size were independently associated with recurrence after TEM. CONCLUSION: Local excision by TEM is oncologically safe and effective for pTis and pT1 rectal cancers and early lesions smaller than 3 cm in diameter.