Clinical findings in 111 cases of influenza A (H7N9) virus infection.

BACKGROUND: During the spring of 2013, a novel avian-origin influenza A (H7N9) virus emerged and spread among humans in China. Data were lacking on the clinical characteristics of the infections caused by this virus. METHODS: Using medical charts, we collected data on 111 patients with laboratory-confirmed avian-origin influenza A (H7N9) infection through May 10, 2013. RESULTS: Of the 111 patients we studied, 76.6% were admitted to an intensive care unit (ICU), and 27.0% died. The median age was 61 years, and 42.3% were 65 years of age or older; 31.5% were female. A total of 61.3% of the patients had at least one underlying medical condition. Fever and cough were the most common presenting symptoms. On admission, 108 patients (97.3%) had findings consistent with pneumonia. Bilateral ground-glass opacities and consolidation were the typical radiologic findings. Lymphocytopenia was observed in 88.3% of patients, and thrombocytopenia in 73.0%. Treatment with antiviral drugs was initiated in 108 patients (97.3%) at a median of 7 days after the onset of illness. The median times from the onset of illness and from the initiation of antiviral therapy to a negative viral test result on real-time reverse-transcriptase-polymerase-chain-reaction assay were 11 days (interquartile range, 9 to 16) and 6 days (interquartile range, 4 to 7), respectively. Multivariate analysis revealed that the presence of a coexisting medical condition was the only independent risk factor for the acute respiratory distress syndrome (ARDS) (odds ratio, 3.42; 95% confidence interval, 1.21 to 9.70; P=0.02). CONCLUSIONS: During the evaluation period, the novel H7N9 virus caused severe illness, including pneumonia and ARDS, with high rates of ICU admission and death. (Funded by the National Natural Science Foundation of China and others.).

Effect of PIFR-based optimised inhalation therapy in patients recovering from acute exacerbation of chronic obstructive pulmonary disease: protocol of a prospective, multicentre, superiority, randomised controlled trial.

INTRODUCTION: Acute exacerbation (AE) is a major cause of disease progression and death in patients with chronic obstructive pulmonary disease (COPD), accounting for majority of medical expenditures. Correct inhalation therapy is effective in preventing AE attacks. However, inappropriate usage of dry powder inhaler, partially due to the unrecovered peak inhalation flow rate (PIFR) after acute exacerbation of COPD (AECOPD), results in increased risk of early treatment failure. Therefore, we designed a multicentre, randomised clinical trial to determine whether PIFR-based optimised inhalation therapy and training on inhaler usage at discharge could effectively reduce early treatment failure events. METHODS AND ANALYSIS: A total of 416 hospitalised patients just recovering from AECOPD will be recruited and equally randomised into the PIFR group and the control group at a 1:1 ratio. The PIFR group will receive additive support before discharge, including choice of PIFR-guided inhaler and education on its usage. PIFR is measured by InCheck DIAL. In comparison, the control group will receive inhalers based on judgement of the respiratory physician. The primary outcome of the study is 30-day treatment failure rate. Other endpoints include PIFR, error rate of inhalation device use, satisfaction with inhalation devices, 30-day mortality, 90-day mortality, symptoms and quality of life of patients, and COPD-related treatment costs. ETHICS AND DISSEMINATION: The trial has been approved by the Ethics Committee of Zhongshan Hospital of Fudan University (B2019-142). Participants will be screened and enrolled from hospitalised patients with AECOPD by clinicians, with no public advertisement for recruitment. After the trial has completed, the results will be reported to the public through conference presentations and peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04000958.

Assessing risk factors for SARS-CoV-2 infection in patients presenting with symptoms in Shanghai, China: a multicentre, observational cohort study.

Background: The outbreak of COVID-19 has led to international concern. We aimed to establish an effective screening strategy in Shanghai, China, to aid early identification of patients with COVID-19. Methods: We did a multicentre, observational cohort study in fever clinics of 25 hospitals in 16 districts of Shanghai. All patients visiting the clinics within the study period were included. A strategy for COVID-19 screening was presented and then suspected cases were monitored and analysed until they were confirmed as cases or excluded. Logistic regression was used to determine the risk factors of COVID-19. Findings: We enrolled patients visiting fever clinics from Jan 17 to Feb 16, 2020. Among 53 617 patients visiting fever clinics, 1004 (1·9%) were considered as suspected cases, with 188 (0·4% of all patients, 18·7% of suspected cases) eventually diagnosed as confirmed cases. 154 patients with missing data were excluded from the analysis. Exposure history (odds ratio [OR] 4·16, 95% CI 2·74-6·33; p<0·0001), fatigue (OR 1·56, 1·01-2·41; p=0·043), white blood cell count less than 4 × 109 per L (OR 2·44, 1·28-4·64; p=0·0066), lymphocyte count less than 0·8 × 109 per L (OR 1·82, 1·00-3·31; p=0·049), ground glass opacity (OR 1·95, 1·32-2·89; p=0·0009), and having both lungs affected (OR 1·54, 1·04-2·28; p=0·032) were independent risk factors for confirmed COVID-19. Interpretation: The screening strategy was effective for confirming or excluding COVID-19 during the spread of this contagious disease. Relevant independent risk factors identified in this study might be helpful for early recognition of the disease. Funding: National Natural Science Foundation of China.

Negative regulation of c-Myc transcription by pancreas duodenum homeobox-1.

The pancreatic and duodenal homeobox factor-1 (Pdx1) is essential for pancreatic development and insulin gene transcription, whereas c-Myc has a deleterious effect on islet function. However, the relationship between c-Myc and Pdx1 is poorly concerned. Here we demonstrated that Pdx1 could suppress c-Myc promoter activity, which relied on T cell factor (Tcf) binding elements harbored in c-Myc promoter. Furthermore, the transcription activity of beta-catenin/Tcf was markedly decreased on Pdx1 expression, but cotransfection of Pdx1 short hairpin RNA abrogated this effect. Pdx1 expression did not induce beta-catenin degradation nor did it alter their subcellular distribution. The mutation analysis showed that the amino acids (1-209) of Pdx1 harboring an inhibitory domain, which might lead to the reduction of beta-catenin/Tcf/p300 complex levels and attenuate their binding activity with c-Myc promoter sequences. Moreover, adenovirus-mediated Pdx1 interference caused cell proliferation and cytokine-induced apoptosis via the dysregulation of c-Myc transcription. These results indicated that the Pdx1 functioned as a key regulator for maintenance of beta-cell function, at least in part, through controlling c-Myc expression and the loss of its regulatory function may be an alternative mechanism for beta-cell neogenesis and apoptosis found in diabetes.

Negatively regulating mechanism of Sirpalpha1 in hepatocellular carcinoma: an experimental study.

BACKGROUND: Signal regulatory protein (Sirp) is a recently isolated, cloned and identified inhibitor receptor distributed in the membrane of hematopoietic and nonhematopoietic cells. Sirp alpha1 (Sirpalpha1) is a member of Sirp families. Sirpalpha1 can bind SHP-2 in the form of tyrosine phosphorylation by SH2 effect and negatively regulate growth factor, oncogene, or insulin-induced responses as its substrate. This study aimed to preliminarily clarify the negatively regulating proliferation mechanism of Sirpalpha1 in liver cancer. METHODS: pLXSN, Sirpalpha1 and Sirpalpha1P4Y2 plasmids were respectively transfected into Sk-Hep1 liver cancer cell line, and various stable Sk-Hep1 cell lines were obtained with screening agent of G418 (1200 microg/ml). The expressing levels of cyclin D1, CDK4, Fas, beta-catenin and gankyrin in various cell lines were determined with Western blotting. Cell cycles were determined at 0, 12 and 24 hours with flow cytometry after various synchronous cell lines were cultured without serum for 72. Cell apoptosis induced with agent of TNF-alpha (50 ng/ml) was determined with flow cytometry at 0, 0.5, 1, 3, 6 and 12 hours. RESULTS: Sirpalpha1 could significantly decrease the expression of cyclin D1, beta-catenin and gankyrin, but it couldn't affect the expression level of CDK4 and Fas. When synchronous cells were cultured for 12 hours, S phase Sk-Hep1 cell transfected with Sirpalpha1 plasmid was the lowest [(31.92+/-0.22)% vs. other cell lines, P<0.05], and the cell line was highly sensitive to TNF-alpha agent for 1 hour. (59.31+/-0.59)% of apoptotic cells occurred (vs. the other time points, P<0.05). CONCLUSIONS: Sirpalpha1 might block the cell cycle of liver cancer, inhibit cell proliferation, promote cell apoptosis by decreasing the expression of cyclin D1, beta-catenin and gankyrin. It is one of the important mechanisms inhibiting the occurrence and development of hepatocellular carcinoma.

Effects of signal regulatory proteinalpha1 on proliferation of hepatocellular carcinoma: a preliminary study.

BACKGROUND: Signal regulatory protein alpha1 (Sirpalpha1) is a negative regulatory factor, and inhibits receptor tyrosine kinase-dependent cell proliferating signal. This study was undertaken to observe the effect of signal regulatory proteinalpha1 (Sirpalpha1)on gankyrin,cyclin D1,CDK4 and Fas expression in Sk-hep1 mouse hepatoma carcinoma cell line. METHODS: BOSC 23 packed cells were respectively transfected by means of recombinated retrovirus including pLXSN, pLXSN- Sirpalpha1 and pLXSN- Sirpalpha1P4Y2 with lipofectin, and various plasmid virus media(viral titer 2.1X10(6) CFU/ml) were collected and infected respectively in 80% confluent Sk-hep1 cells. Transfected Sk-hep1 cells were selectively screened with G418 (1200 mug/ml), and Sk-hep1 cell lines transfected with various plasmids were obtained. The protein expressions of gankyrin, cyclin D1, CDK4 and Fas in various Sk-hep1 lines were determined by Western blotting. Various Sk-hep1 lines were recovered to culture with 10% fetal bovine serum at 12 hours and 24 hours after starving culture with free serum for 72 hours, and cells were collected to determine the percentage of S phase cells of proliferating cycle by flow cytometry. RESULTS: Sirpalpha1 transfection remarkably downregulated gankyrin and cyclin D1 expression. Sirpalpha1P4Y2 downregulation of gankyrin expression was greater than that of Sirpalpha1 (P<0.05), but no significant effect of Sirpalpha1 and Sirpalpha1P4Y2 on CDK4 and Fas protein expression was observed in transfected Sk-hep1 lines (P>0.05). The percentage of S phase cells significantly decreased in Sk-hep1 cells transfected with Sirpalpha1 and Sirpalpha1P4Y2 plasmids (vs pLXSN Sk-hep1, P<0.05). The percentage of S phase cells in various Sk-hep1 cells increased when recovering to culture with 10% fetal bovine serum at 12 hours, but the percentage of S phase cells in Sk-hep1 cells transfected with Sirpalpha1 was the lowest (vs pLXSN and Sirpalpha1P4Y2 Sk-hep1, P<0.05). The percentage of S phase cells in transfected pLSXN Sk-hep1 cells was the largest (vs Sirpalpha1 and Sirpalpha1P4Y2 Sk-hep1, P<0.05). There was no significant difference between the transfected Sirpalpha1 Sk-hep1 cells and Sirpalpha1P4Y2 Sk-hep1 cells (P>0.05). CONCLUSIONS: Sirpalpha1 decreases gankyrin and cyclin D1 expression, and inhibits proliferation of liver carcinoma cells. It may be one of the forms for an Sirpalpha1 negative regulation of carcinogenesis and development of hepatocellular carcinoma.

A confirmed severe case of human infection with avian-origin influenza H7N9: A case report.

A male patient, aged 77 years, was admitted to hospital with the chief complaint of persistent hyperpyrexia that had presented for four days. The patient also suffered from hypoxemia, and a large white shadow in the left lung was observed on a chest radiograph, indicating inflammation. No therapeutic effect was observed with anti-infection treatment. The patient admitted a history of direct contact with live chickens two weeks prior to hospital admission. The day after admission to the Jingnan District Centre Hospital of Shanghai (Shanghai, China), the patient was diagnosed with severe H7N9 avian influenza infection by nasopharyngeal swab and blood sampling detection. Although the patient received anti-infective drugs, intubated assisted ventilation and circulation support, the condition of the patient continued to rapidly deteriorate. Oxygen saturation decreased and gastrointestinal bleeding occurred, with the body temperature fluctuating between 39 and 40°C. By day 6 after admission, the patient presented with circulatory failure, with liver and renal failure. On day 7, the blood pressure of the patient was unable to be measured, and the patient was diagnosed with multiple organ dysfunction. Subsequently, clinical death was declared with the patient exhibiting asystole and no spontaneous breathing.

Overexpression of p28/gankyrin in human hepatocellular carcinoma and its clinical significance.

AIM: To investigate the expression of p28/gankyrin gene and its role in the carcinogenetic process of human hepatocellular carcinoma (HCC). METHODS: 64 specimens of HCC and para-carcinoma tissues, 22 specimens of non-tumor liver tissues (7 normal, 15 cirrhosis), 10 specimens of normal human tissues and 5 hepatoma cell lines were studied for the expression of p28/gankyrin by Northern blot. The expression of p28/gankyrin protein was detected immunohistochemically by using the specific polyclonal antibody. RESULTS: Northern blot analysis indicated that the expression of p28/gankyrin mRNA was intensively distributed in brain and heart, weakly in lung, spleen and muscle, undetectable in digestive system including liver, pancreas, stomach, small and large intestines. p28/gankyrin mRNA was absent in normal liver, weakly detected in liver cirrhosis and in 18 of 64 para-carcinoma liver tissues. In contrast, the expression of p28/gankyrin mRNA was intensively detected in all 5 hepatoma cell lines tested, markedly increased in 57 of 64 and moderately increased in 5 of 64 HCC samples. In comparison with liver cirrhosis and para-carcinoma liver tissues, the average expression of p28/gankyrin mRNA in HCC was increased 3.6- (2.901+/-0.507 vs 0.805+/-0.252, P<0.05) and 5.2-fold (2.901+/-0.507 vs 0.557+/-0.203, P<0.01), respectively. In addition, p28/gankyrin mRNA expression level was higher in HCC with portal vein tumor thrombus and microscopic hepatic vein involvement (P=0.021 and P=0.047, respectively). The overexpression of p28/gankyrin protein in HCC was targeted in hepatic tumor cells, not in bile duct cells and other interstitial cells. CONCLUSION: Overexpression of p28/gankyrin in HCC plays an important role and contributes to the metastasis potential in the process of carcinogenesis. p28/gankyrin may become a specific biological tissue marker for the pathological diagnosis of HCC.

Expression of cytochrome P4502E1 gene in hepatocellular carcinoma.

AIM: To investigate cytochrome P4502E1 (CYP2E1) gene expression in occurrence and progression of hepatocellular carcinoma (HCC). METHODS: The human liver arrayed library was spotted onto the nylon membranes to make cDNA array. Hybridization of cDNA array was performed with labeled probes synthesized from RNA isolated from HCC and adjacent liver tissues. Sprague-Dawley rats were administrated diethylnitrosamine (DENA) to induce HCC. CYP2E1 expression was detected by the method of RT-PCR and Northern blot analysis. RESULTS: CYP2E1 was found by cDNA array hybridization to express differently between HCC and liver tissues. CYP2E1 only expressed in liver, but did not express in HCC tissues and expressed lowly in cirrhotic tissues. In the progression of cirrhosis and HCC, the expression level of CYP2E1 was gradually decreased and hardly detected until the late stage of HCC. CONCLUSION: Using arrayed library to make cDNA arrays is an effective method to find differential expression genes. CYP2E1 is a unique gene expressing in liver but did not express in HCC. CYP2E1 expression descended along with the initiation and progression of HCC, which is noteworthy further investigations in its significance in the development of HCC.

[Treatment of hepatocellular carcinoma by transfecting interleukin-12 and interleukin-2 fusion gene intrasplenically, an experimental study].

OBJECTIVE: To study the inhibitory effect of retroviral packaging cells injected intrasplenically encoding mouse interleukin-12 (mIL-12) and human interleukin-2 (hIL-2) fusion gene on the growth of hepatocellular carcinoma. METHODS: The retroviral vectors encoding mIL-12 gene, hIL-2 gene, and mIL-12 and hIL-2 genes, GCIL12EXPN, GCXEIL2PN, and GCIL12EIL2PN were constructed and then transfected into the retroviral packaging cells PA317 to construct cells PA317-GCIL12EXPN, PA317-GCXEIL2PN, and PA317-GCIL12EIL2PN. Rat hepatocellular carcinoma cells CBRH3 were implanted into the livers of Wistar rats to establish hepatoma animal model. Then the rats were divided into 5 groups to be injected intrasplenically with normal saline one day after the implantation (0.8 ml/rat, group I, n = 10), blank vector PA317-GCXEXPN one day after the implantation (10(7) cells/rat, group II, n = 10), PA317-GCIL12EXPN containing IL-2 gene (1 x 10(7) cells/rat 1, 3, 5, or 7 days after the implantation, group III, n = 40), PA317-GCXEIL2PN containing mIL-12 gene (1 x 10(7) cells/rat 1, 3, 5, or 7 days after the implantation, group IV, n = 40), and PA317-GCIL12EIL2PN containing IL-12-IL-2 fusion gene (1 x 10(7) cells/rat 1, 3, 5, or 7 days after the implantation, group V, n = 40) respectively. The rats surviving longer than 2 months were re-injected with hepatocellular carcinoma cells. The therapeutic effect, immune function and toxic effect were evaluated. CT was conducted on the liver before and after the experiment. Laparotomy was performed 3 and 7 days after treatment to resect some of the carcinoma tissues to undergo pathological examination and OX8 immunohistostaining. Serum mIL-12 and hIL-2 were detected one day before and 3, 7, 30, and 60 days after treatment. RESULTS: The average survival times of the rats treated with IL-12-IL-2 fusion gene at the first, third, fifth and seventh day after tumor implantation were 53.3 +/- 3.7 days, 49.3 +/- 4.2 days, 31.0 +/- 2.1 days, and 24.3 +/- 1.4 days respectively, longer than those treated with IL-2 gene (25.0 +/- 2.5 days, 23.5 +/- 2.0 days, 18.3 +/- 2.4 days, and 12.0 +/- 1.8 days respectively, P < 0.001), and those treated with IL-12 gene (39.0 +/- 4.8 days, 32.0 +/- 3.9 days, 23.0 +/- 2.5 days, and 19.4 +/- 2.1 days respectively, P < 0.001). Long survival (>or= 60 days) rate in the rats treated with IL-12-IL-2 fusion gene on the first and third day was 30%. The serum mIL-12 and hIL-2 levels in these rats remained high on the 60th day after treatment. The pathological study showed that the number of infiltrating lymphocytes in liver tumor tissues was increased in the IL-12-IL-2 fusion gene treatment group. CONCLUSION: The retroviral packaging cell line injected intrasplenically encoding mIL-12 and hIL-2 fusion gene inhibits the growth of hepatocellular carcinoma significantly in rats. The therapeutical efficacy of early administration is superior to that of late one.

[PTEN expression and its significance in human primary hepatocellular carcinoma].

OBJECTIVES: To explore the significance of PTEN (phosphatase and tensin homolog deleted on chromosome 10) in the development of human primary hepatocellular carcinoma (HCC). METHODS: PTEN protein expression in cancerous liver tissues and paired para-carcinoma liver tissues from 60 HCC patients was detected by immunohistochemistry and PTEN mRNA expression was analyzed by northern blot. The significance of PTEN in the development of HCC was analyzed by investigating the relationship between the expression levels of PTEN protein and mRNA, and the clinicopathological parameters of HCC patients. RESULTS: PTEN protein was immunohistochemically stained in the cytoplasmic region of para-carcinoma liver tissues in all the 60 patients, while only 48.3% (29/60) of the patients were positive for PTEN protein in cancerous liver tissues. The positive rate of PTEN protein in HCC tissues were relative to the histological gading and the presence of tumor thrombus. In grade I - II, III, and IV, the positive rates were 84.0%, 23.8%, and 21.4% respectively, and in the group with tumor thrombus was 26.7%, while in the group without tumor thrombus was 55.6%. Northern blot showed that there existed four PTEN mRNA transcripts with the length of 5.5kb, 4.4kb, 2.4kb, and 1.8kb respectively. The level of PTEN mRNA expression in HCC tissues was much lower than that in the paired para-carcinoma liver tissues. The low expression level of the 5.5kb and 4.4kb transcripts was significantly associated with serum AFP value, presence of tumor thrombus, state of satellite lesion and histological grading. The low expression level of the 2.4kb transcript in HCC was significantly associated with the presence of tumor thrombus and satellite lesions in HCC patients. However, no evident relationship between the lowered expression level of the 1.8kb transcript and the clinicopathological parameters of HCC was observed in these 60 patients. CONCLUSIONS: Down-regulation of PTEN expression may play an important role in the development of HCC and the expression level of PTEN may be a potential adjuvant parameter in forecasting the progress and prognosis of HCC.

[Clinical research on children mental retardation treated with acupuncture].

OBJECTIVE: To observe the impacts of acupuncture on intelligent structure, social adaptability and fMRI brain function in children mental retardation (MR). METHODS: Sixty cases of MR in compliance with the diagnostic standard were randomized into an acupuncture group and a medication group, 30 cases in each one. In the acupuncture group, Sishenzhen [four points, 1.5 cun anterior, posterior and bilateral to Baihui (GV 20)], Zhisanzhen [Shenting (GV 24), bilateral Benshen (GB 13)], Niesanzhen (the point 2 cun directly above the ear a-pex, the two points 1 cun bilateral the first point) and Naosanzhan [Naohu (GV 17) and bilateral Naohu (GB 19)] were selected as the main points. In the medication group, piracetam tablets were prescribed for oral administration. One course of treatment was 4 months in the two groups. The comprehensive efficacy was compared between the two groups at the end of treatment course. China-Wechsler Intelligence Scale for Children (C-WISC) was used to assess the intelligent improvements. Infant-Junior School Student Social Life Ability Scale was adopted to assess the improvements of social adaptability. Five cases were selected from the acupuncture group and fMRI was adopted to compare the brain function imaging changes before and after acupuncture treatment. METHODS: In the acupuncture group, the final intelligence quotient (FIQ) and social adaptability score after treatment were higher than those before treatment (P<0.05), of which, the performance intelligence quotient (PIQ) was improved significantly, indicating the statistically significant difference (P<0.05). But the verbal intelligence quotient (VIQ) did not change apparently (P>0.05). In the medication group, the changes in all the indices were not apparent before and after treatment (P>0.05). In comparison of the changes after treatment between the two groups, FIQ, PIQ and social adaptability score in the acupuncture group were improved more significantly as compared with the medication group (P<0.05). The fMRI brain function images did not change apparently before and after treatment in those 5 cases of the acupuncture group. CONCLUSION: Acupuncture promotes the intelligent recovery of MR children and improves their social adaptability. It indicates the satisfactory clinical efficacy. But, the fMRI brain function images do not change apparently before and after treatment.

The role of p28GANK in rat oval cells activation and proliferation.

BACKGROUND: Human gankyrin gene product (p28GANK) is a novel oncogenic protein ubiquitously overexpressed in hepatocellular carcinoma and also plays a role in cell cycle progression in normal hepatocytes and liver regeneration. However, little is known about the physiological role of p28GANK in the liver oval cell activation and proliferation. We investigated the possible involvement of p28GANK in oval cell-mediated liver regeneration and cell cycle progression. METHODS: We examined the different p28GANK expression in 2-acetylaminofuorene/partial heptectomy (2-AAF/PH) rats, as a model of oval cell activation, and PH rats by Western blot and immunohistochemistry. Oval cells isolated from 2-AAF/PH rat model were cultured in our study. p28GANK expression was examined in the oval cells after mitogenic stimulation. RESULTS: In 2-AAF/PH rats, p28GANK was expressed in the activated oval cells and located in the nucleus. p28GANK protein expression was increased in 2-AFF/PH rats after hepatectomy lasting for 96 h when retinoblastoma maintained hyperphosphorylation status at Ser-795. The isolated oval cells express AFP, OV6, CK19, CD34, CD45, c-kit and albumin. After epidermal growth factor stimulation, p28GANK protein was up-regulated in oval cells from 24 to 72 h, which coincided with increased expression of CyclinD1, CDK4 and decreased of Rb protein. CONCLUSIONS: p28GANK expression was increased in oval cell-mediated liver regeneration and oval cells after mitogenic stimulation. Thus, p28GANK may play a role in oval cell-mediated liver regeneration and liver oval cell cycle progression.

Protein-tyrosine phosphatase PCP-2 inhibits beta-catenin signaling and increases E-cadherin-dependent cell adhesion.

beta-Catenin is a key molecule involved in both cell adhesion and Wnt signaling pathway. However, the exact relationship between these two roles has not been clearly elucidated. Tyrosine phosphorylation of beta-catenin was shown to decrease its binding to E-cadherin, leading to decreased cell adhesion and increased beta-catenin signaling. We have previously shown that receptor-like protein-tyrosine phosphatase PCP-2 localizes to the adherens junctions and directly binds and dephosphorylates beta-catenin, suggesting that PCP-2 might regulate the balance between signaling and adhesive beta-catenin. Here we demonstrate that PCP-2 can inhibit both the wild-type and constitutively active forms of beta-catenin in activating target genes such as c-myc. The phosphatase activity of PCP-2 is required for this effect since loss of catalytic activity attenuates its inhibitory effect on beta-catenin activation. Expression of PCP-2 in SW480 colon cancer cells can lead to stabilization of cytosolic pools of beta-catenin perhaps, by virtue of their physical interaction. PCP-2 expression also leads to increased membrane-bound E-cadherin and greater stabilization of adherens junctions by dephosphorylation of beta-catenin, which could further sequester cytosolic beta-catenin and thus inhibit beta-catenin mediated nuclear signaling. Furthermore, SW480 cells stably expressing PCP-2 have a reduced ability to proliferate and migrate. Thus, PCP-2 may play an important role in the maintenance of epithelial integrity, and a loss of its regulatory function may be an alternative mechanism for activating beta-catenin signaling.

In situ detection of tumor infiltrating lymphocytes expressing perforin and fas ligand genes in human HCC.

AIM:To investigate the expression of perforin and fas-ligand (fas-L) of tumor infiltrating lymphocytes (TILs) in human hepatocellular carcinoma (HCC).METHODS:By in situ hybridization and immunohistochemistry, the perforin and fas-L gene expression of TILs was studied in 20 HCC cases.RESULTS: Positive expression of perforin and fas-L genes was detected in 16 HCC cases. One patient had expression of perforin and fas-L genes in the majority of TILs and survived 1.5 years after tumor resection without HCC relapse.This seems that the presence of a large number of activated T cells might be beneficial for the antitumor immunity. In other cases, less than 10% of TILs were able to express perforin and fas-L genes.CONCLUSION:Although there were a number of T cells in HCC, only few of them were immunoactive and able to kill tumor cells. It seems important to promote further proliferation of these activated T cells in vitro or in vivo.

Physical and functional interaction between receptor-like protein tyrosine phosphatase PCP-2 and beta-catenin.

We have previously identified a human receptor protein tyrosine phosphatase of the MAM domain family, termed PCP-2, in human pancreatic adenocarcinoma cells and found that this protein was colocalized with beta-catenin and E-cadherin at cell junctions [Wang, H.-Y., et al. (1996) Oncogene 12, 2555-2562]. Its intracellular part consists of two tandem phosphatase domains and a relatively large juxtamembrane region that is homologous to the conserved intracellular domain of cadherins, suggesting a role in the regulation of cell adhesion. This study reports that PCP-2 was endogenously expressed at the cell surface and upregulated with increased cell density. An in vivo binding assay revealed that PCP-2 could directly interact with beta-catenin through a region in the juxtamembrane domain. Tyrosine phosphorylation of beta-catenin by EGF or active SrcY527F did not disrupt the formation of the PCP-2-beta-catenin complex, while PCP-2 in this complex could cause a significant reduction in the phosphorylation level in beta-catenin. Finally, we showed that PCP-2 was a negative regulator for cell migration. In conclusion, interaction of PCP-2 with its substrate beta-catenin is involved in the process of cell-cell contact.

Negative regulation of hepatocellular carcinoma cell growth by signal regulatory protein alpha1.

Signal regulatory protein (SIRP) alpha1 is a member of the SIRP family that undergoes tyrosine phosphorylation and binds SHP-2 tyrosine phosphatase in response to various mitogens. The expression levels of SIRPalpha1 were decreased in HCC tissues, compared with the matched normal tissues. Exogenous expression of wild type SIRPalpha1, but not of a mutant SIRPalpha1 lacking the tyrosine phosphorylation sites, in SIRPalpha1-negative Huh7 human HCC cells resulted in suppression of tumor cell growth both in vitro and in vivo. Treatment of Huh7 transfectants with EGF or HGF induced tyrosine phosphorylation of SIRPalpha1 and its association with SHP-2, which were accompanied by reduced ERK1 activation. Expression of SIRPalpha1 significantly suppressed activation of NF-kappaB and also sensitized Huh7 cells to TNFalpha or cisplatin-induced cell death. In addition, SIRPalpha1-transfected Huh7 cells displayed reduced cell migration and cell spreading in a fashion that was dependent on SIRPalpha1/SHP-2 complex formation. In conclusion, a negative regulatory effect of SIRPalpha1 on hepatocarcinogenesis is exerted, at least in part, through inhibition of ERK and NF-kappaB pathways.