Comprehensive comparison of patient-derived xenograft models in Hepatocellular Carcinoma and metastatic Liver Cancer.

Patient-derived xenograft (PDX) models are effective preclinical cancer models that reproduce the tumor microenvironment of the human body. The methods have been widely used for drug screening, biomarker development, co-clinical trials, and personalized medicine. However, the low success rate and the long tumorigenesis period have largely limited their usage. In the present studies, we compared the PDX establishment between hepatocellular cancer (HCC) and metastatic liver cancer (MLC), and identified the key factors affecting the transplantation rate of PDXs. Surgically resected tumor specimens obtained from patients were subcutaneously inoculated into immunodeficient mice to construct PDX models. The overall transplantation rate was 38.5% (20/52), with the HCC group (28.1%, 9/32) being lower than MLC group (56.2%, 9/16). In addition, HCC group took significantly longer latency period than MLC group to construct PDX models. Hematoxylin and eosin staining results showed that the histopathology of all generations in PDX models was similar to the original tumor in all three types of cancer. The transplantation rate of PDX models in HCC patients was significantly associated with blood type (P=0.001), TNM stage (P=0.023), lymph node metastasis (P=0.042) and peripheral blood CA19-9 level (P=0.049), while the transplantation rate of PDX models in MLC patients was significantly associated with tumor size (P=0.034). This study demonstrates that PDX models can effectively reproduce the histological patterns of human tumors. The transplantation rate depends on the type of original tumor. Furthermore, it shows that the invasiveness of the original liver cancer affects the possibility of its growth in immunodeficient mice.

Establishment of pancreatic cancer patient-derived xenograft models and comparison of the differences among the generations.

Tumor samples of pancreatic ductal adenocarcinoma patients, who underwent resection surgery, were implanted into NOD/SCID mice to construct pancreatic cancer patient-derived xenograft (PDX) models and explore the biological changes in the different generations of PDXs. Ten PDXs were successfully generated, and the tumor formation rate of F1 PDXs was found to be 38.46%, which was lower than F2 (77.78%) and F3 (71.43%) PDXs. In addition, latent periods of tumorigenesis of F2 and F3 PDXs were significantly shorter, compared to that in F1 PDXs (P<0.05). Comparison of H&E staining of tumor tissue from primary pancreatic cancer and PDXs showed that all three generations of PDXs had similar histopathology to primary pancreatic cancer, indicating that PDXs may well reproduce the histological patterns of primary human cancer. Besides, Ki67 expression was increased in all three generations of PDXs compared to primary tumors of patients, and additionally, EpCAM expression was increased in F3 PDXs. These results were corroborated by the real-time qPCR and western blot results. Therefore, we concluded that PDXs are able to preserve the differentiation degree, morphological characteristics, and structural features of tumor cells. Furthermore, the latent periods of tumorigenesis are shortened after the first generation, which may be attributed to an increase in expression levels of tumor promoters such as Ki67 and EpCAM. PDX models may become an efficient tool for pancreatic cancer research.

[Excitatory and aversive behaviors - electrophysiological observation of anterior cingulate cortex (ACC) in rats].

OBJECTIVE: Increasing activities in anterior cingulate cortex (ACC) can enhance the aversion reactions associated with noxious stimuli. It has been known that opioid receptors activation can trigger endogenous analgesic effect. This study tried to explore whether opioid receptors activation in the ACC region could reduce the aversion associated with noxious stimuli. METHODS: The experimental rats were randomly divided into seven groups, Complete Freund's adjuvant (CFA) + normal saline (NS) group, normal saline (NS) + normal saline (NS) group, normal saline (NS) +DAMGO ((DAla2, NMe-Phe4, Gly-ol5)enkephinlin, µ-opioid receptor agonist) group, complete Freund's adjuvant (CFA)+ 0.01/0.04/0.2/1 µg/µl DAMGO group(n=6). The experimental period was three days. The basal value was measured on the first day. The second day, 1 µl was administered through the ACC area, and then 0.08 ml of complete Freund's adjuvant (CFA) was injected into the left hind paw of the rat. CPA response, paw withdrawal reflex latency (PWL) and electrical activity in the ACC brain region of rats were observed on the third day. RESULTS: ①PWL was significantly decreased in rats after CFA was injected into left hind paw compared with post-injection(P＜0.05).② In the pain side of the apparatus, it took rats less residence time than that in the non-pain side. ③ 0.04/0.2/1 µg/µl DAMGO was given before CFA-injection, C-CPA reactions could be revised significantly. ④ Given 0.04/0.2/1 µg/µl DAMGO in the ACC region could decrease the increasing discharge frequency induced by CFA in ACC neurons. CONCLUSION: The activation of the mu-opioid receptor in the ACC region alleviates the aversion induced by noxious stimulation.

Superior mesenteric artery margin in pancreaticoduodenectomy for pancreatic adenocarcinoma.

The aim of this study is trying to describe more details of superior mesenteric artery margin in pancreaticoduodenectomy for pancreatic ductal adenocarcinoma, to evaluate biological and prognostic implications of tumor budding in this margin, and to provide more evidence for evaluation of R0 surgery in pancreaticoduodenectomy. 46 patients in 5-years period are included in this study. Immunochemistry and immunofluorescence are used to analyze tumor budding and epithelial-mesenchymal transition. Superior mesenteric artery margin might be described from four aspects including location, gross appearance, microscopic appearance and tumor budding. We find that 1mm rule for R1 surgery is more appropriate to predict prognosis (P = 0.009) than 0mm rule (P = 0.141). Expression of cytokeratin in tumor budding is significantly lower than primary tumor (P = 0.001), and it suggests that tumor budding may participate the procedure of epithelial-mesenchymal transition. High-grade tumor budding and decreasing cytokeratin of tumor budding correlate with distant metastasis and has negative influence on prognosis. So superior mesenteric artery margin might be not only an area that tumor cells may invade, but also a pathway for distant metastasis. It is necessary to evaluate superior mesenteric artery margin in pancreaticoduodenectomy for pancreatic cancer.

p42.3: a promising biomarker for the progression and prognosis of human colorectal cancer.

PURPOSE: As a novel cell cycle-related gene, p42.3 has been shown to play a key role in the cell proliferation and tumorigenicity of gastric cancer. To date, the association between p42.3 and colorectal cancer (CRC) has not been reported. This study investigated the expression of p42.3 and its potential role in human colorectal cancers. METHODS: Real-time polymerase chain reaction and western blotting were used to evaluate p42.3 mRNA and protein expression in 14 pairs of fresh frozen CRC samples, matched with adjacent normal mucosa. The p42.3 protein was evaluated by immunohistochemistry using CRC tissue microarrays, which included 212 CRC specimens and corresponding normal colorectal mucosa. The expression profiles of p42.3 in CRC tissues were analyzed against clinicopathological factors and post-surgical survival status. The expression profiles of p42.3 were also investigated in six human colon carcinoma cell lines. RESULTS: p42.3 was demonstrated to be over-expressed in colorectal cancer tissues compared with normal mucosa in the 14 tissue pairs (P = 0.011) and was significantly higher in patients with poor tumor differentiation (P = 0.045); patients positive for p42.3 expression had a poorer prognosis than those not expressing this protein (P = 0.033). In a multivariate survival analysis, p42.3 expression was identified as an independent prognostic factor for CRC patients (P = 0.030). CONCLUSIONS: The results indicated that p42.3 might play an important role in the progression of CRC, and it has a great value for assessing CRC patient prognosis after surgery.

Expression of MMP-9 and WAVE3 in colorectal cancer and its relationship to clinicopathological features.

PURPOSE: To investigate matrix metalloproteinase 9 (MMP-9) and WAVE3 expression in human colorectal cancer (CRC) and to evaluate their clinical significance. METHODS: We first performed real-time PCR to evaluate mRNA expression of MMP-9 and WAVE3 in 21 pairs of fresh CRC samples matched with adjacent normal mucosa. Then, MMP-9 and WAVE3 proteins were evaluated by immunohistochemistry on CRC tissue microarrays which included 216 CRC specimens and corresponding normal colorectal mucosa, and their correlation with clinicopathological factors and overall survival after surgery was evaluated. RESULTS: Both real-time PCR and immunohistochemistry evaluation have demonstrated that MMP-9 and WAVE3 were over-expressed in colorectal cancer tissues compared with normal mucosa (p < 0.001). MMP-9 expression was significantly higher in patients with low-grade differentiation and distant metastasis (p = 0.003 and p = 0.005, respectively), and patients with MMP-9-positive expression had a poorer prognosis (p = 0.008). However, patients with WAVE3-positive expression had a better prognosis (p = 0.039) and particularly favorable prognostic factors, including non-lymph node metastasis, non-distant metastasis, and early TNM stage (p = 0.029, 0.021, and 0.003, respectively). In addition, MMP-9-negative/WAVE3-positive patients had the best overall survival (p = 0.021). In multivariate survival analysis, MMP-9 expression and combined expression status of MMP-9/WAVE3 were identified as independent prognostic factors for CRC (p = 0.046 and p = 0.019, respectively). CONCLUSIONS: Combined analysis of MMP-9 and WAVE3 has a significant value for assessing prognosis of CRC patients after surgery.