Tumor del estroma gastrointestinal y trasplante renal / Gastrointestinal stromal tumor and renal transplant

El tumor estromal gastrointestinal (GIST) representa alrededor del 1% de todos los tumores digestivos y su aparición en pacientes trasplantados renales es infrecuente. Aproximadamente el 95% muestra tinción positiva para c-kit/CD117. DOG1 es un anticuerpo recientemente descrito que se sobre-expresa en los GIST, incluso en c-kit/ CD117 negativos. El diagnóstico preciso de GIST resulta imperativo, debido a la disponibilidad y la creciente eficacia de los inhibidores de la tirosina quinasa en estos tumores, incluso en el subgrupo c-kit/ CD117 negativo. Se presenta el caso de una mujer trasplantada renal inicialmente con GIST en intestino delgado y débil positividad para CD117 tratada con cirugía y recidiva tumoral a los tres años, pérdida de la expresión CD117 y tinción positiva para DOG1. Recibió tratamiento exitoso con imatimib sin presentar recaída tumoral durante un seguimiento de cinco años.

Gastrointestinal stromal tumor (GIST) accounts for nearly 1% of all gastrointestinal tumors. Its association with renal transplantation is not frequent. Approximately 95% of GIST show staining for CD177. DOG1 is a recently described monoclonal antibody that shows positivity even in the absence of CD177 staining. The diagnosis of GIST should be pursued because of the availability of very effective treatments with tyrosine-kinase inhibitors. Herein, we describe the case of a woman with renal transplant who presented a small bowel GIST and weak positivity for CD177, treated initially with surgery. Tumor recurrence was documented 3 years later and histopatology showed loss of CD177 staining and positivity for DOG1. She was treated with imatimib without further recurrence after five years of follow up.

Expression of TMEM16A in the colon of intractable functional constipation patients and its clinical implications / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the expression of TMEMl6A in the colon of intractable functional constipation patients and its clinical implications.</p><p><b>METHODS</b>A total of 30 patients with intractable chronic functional constipation were selected as trial group (full thickness tissue of sigmoid colon), 30 patients with colon cancer as control group (distant tissues at least 5 cm away from cancer). Tissues from two groups were collected in our hospital from February 2012 to June 2014 and confirmed by pathological diagnosis. Immunofluorescence staining, RT-PCR and Western blot were performed to detect the mRNA and protein expression of TMEM16A and c-kit in colon.</p><p><b>RESULTS</b>TMEM16A and c-kit protein expressions were observed in similar sites of colon tissues in two groups. Expressions of TMEM16A and C-kit in colon tissues detected by immunofluorescence, RT-PCR, and Western blotting were significantly lower in trial group than those in control group (TMEM16A: mean A 1.84±0.25 vs. 3.65±0.32, P<0.05, gray intensity ratio 0.66±0.07 vs. 1.04±0.17, P<0.05, relative mRNA 0.41±0.05 vs. 1.00, P<0.05; c-kit: mean A 3.38±0.24 vs. 5.06±0.31, gray intensity ratio 0.64±0.06 vs. 0.98±0.09, relative mRNA 0.18±0.08 vs. 1.00, all P<0.05).</p><p><b>CONCLUSIONS</b>TMEM16A expression in colon tissues of intractable functional constipation patients is significantly lower and may adjust the movement of colonic smooth muscle by regulating the c-kit expression. TMEMl6A may be used as a new candidate target for diagnosis and treatment of intractable functional constipation.</p>

Effect of enhanced green fluorescent protein fusion on Ano1 physiological feature / 生理学报

The aim of the present study was to investigate whether the physiological features of Ano1 were affected by enhanced green fluorescent protein (EGFP) fusing at Ano1 C-terminal. The eukaryotic expression vectors of Ano1 and EGFP-Ano1 were constructed, and these plasmids were transfected into Fischer rat thyroid follicular epithelial (FRT) cells using liposome. The expression and location of Ano1 were examined by using inverted fluorescence microscope. The ability of Ano1 to transport iodide was detected by kinetics experiment of fluorescence quenching. The results showed that both Ano1 and EGFP-Ano1 were expressed on FRT cell membrane and could be activated by Ca(2+). There was no significant difference of the ability to transport iodide between Ano1 and EGFP-Ano1. These results suggest Ano1 and EGFP-Ano1 have similar physiological feature.

Effects of stable ANO1 overexpression on biological behaviors of human laryngeal squamous cell carcinoma Hep-2 cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To detect the effects of ANO1 overexpression on the biological behaviors of human laryngeal squamous cell carcinoma Hep-2 cells.</p><p><b>METHODS</b>A Hep-2 cell line stably overexpressing ANO1 were examined with flow cytometry, soft agar assay, wound healing assay, siRNA experiments, and chloride channel block with DIDS to observe the effect of ANO1 overexpression on the growth, migration and invasion of the cells.</p><p><b>RESULTS</b>Flow cytometry revealed a comparable cell percentage in G0/G1 phase between ANO1-overexpressing cells and the control cells (P>0.05). The two cells showed no significant difference in soft agar assay (P>0.05), but in wound healing experiments, ANO1-overexpressing cells showed significantly accelerated migration (P<0.05), whereas siRNA-mediated silencing of ANO1 significantly inhibited the cell migration (P<0.05). Treatment with DIDS resulted in an effective block of the ANO1 chloride channel activity and obviously decreased the migration speed of Hep-2 cells.</p><p><b>CONCLUSION</b>ANO1 overexpression does not significantly affect the proliferation of cancer cells, but can enhance the migration ability of head and neck squamous cell carcinoma, suggesting the value of ANO1 as a new gene therapy target for head and neck squamous cell carcinoma.</p>

Effects of membrane protein ANO1 stable overexpression on laryngocarcinoma Hep-2 cells / 中国医学科学院学报

<p><b>OBJECTIVE</b>To explore the effects of ANO1 overexpression on the proliferation, detachment, spreading, and migration of laryngocarcinoma Hep-2 cell line.</p><p><b>METHODS</b>ANO1-overexpressing Hep-2 cell line was selected as the assay group, and Hep-2 cell line with empty plasmid was selected as the control group. MTT assay was used to detect the proliferation abilities of Hep-2 cells in both two groups. Cell detachment assay and spreading assay were used to detect the detachment and spreading abilities of Hep-2 cells. Boyden chamber invasion assay, wound healing assay in vitro, and niflumic acid block chloride channel were used to detect the migration abilities of Hep-2 cells. All data were analyzed by SPSS 10.0 software package.</p><p><b>RESULTS</b>Cell proliferation assay by MTT showed that, compared with the control group, the optical density value of assay group was not significantly different (P=0.62). The results of cell detachment assay and cell spreading assay showed the cell detachment rates and cell spreading rates in assay group were significantly higher than those in control group (P<0.0001). The results of Boyden chamber invasion assay showed the percentages of cells migrating through the membrane in assay group were significantly higher than those in control group (P<0.0001). The results of in vitro wound healing experiments showed the wound area rate in assay group was significantly lower than that in control group (P<0.0001). The results of niflumic acid blocking chloride channel experiments showed the wound area rates in assay group were significantly higher than those in control group (P<0.0001).</p><p><b>CONCLUSION</b>ANO1 overexpression does not remarkably alter the proliferation rate of cancer cells, but increases the migration, spreading, and detachment capacities of head and neck squamous cell carcinoma.</p>

Expression of DOG-1 in gastrointestinal stromal tumors and its significance / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To identify the expression of DOG-1 in gastrointestinal stromal tumors (GIST) and to explore its potential association with clinicopathological features of GIST.</p><p><b>METHODS</b>Two tissue microarrays (TMA) were used for the study. Each TMA contained 80 tissue samples of GIST from 80 different patients, with each tumor represented by one core, and paraffin-embedded sections of 40 samples from normal gastrointestinal tissue were used as control. Immunohistochemistry staining (SABC method) was performed on TMA and paraffin-embedded sections to detected the expression of c-Kit (CD117) and DOG-1.</p><p><b>RESULTS</b>Immunohistochemistry showed that in 80 GIST patients, 76 cases (95.0%) were DOG-1 positive and 67 cases (83.8%) were CD117 positive. The positive rate of DOG-1 was higher than that of CD117 (P<0.05). In 13 GIST samples of negative CD117, the positive rate of DOG-1 was 100%. Expressions of both DOG-1 and CD117 were negative in all the 40 samples of normal gastrointestinal tissue. The positive expression of DOG-1 and CD117 was not significantly different in spindle cell type (96.0% vs. 96.0%, P>0.05) and in mixed cell type (91.7% vs. 75.0%, P>0.05). While in the epithelioid cell type, the DOG-1 expression was higher than CD117 expression (94.1% vs. 52.9%, P<0.05). The positive expression of DOG-1 and CD117 was not associated with age, gender, location and risk stratification of the tumors (all P>0.05).</p><p><b>CONCLUSIONS</b>DOG-1 expression is up-regulated in gastrointestinal stromal tumors, especially in epithelioid cell GIST, and may be used as a new marker in the diagnosis of GIST.</p>

Expression of TMEM16A in gastric carcinoma and its clinical implications / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expression of TMEM16A in gastric carcinoma and its clinical implications.</p><p><b>METHODS</b>A total of 72 surgical specimens of gastric carcinoma were collected for examination of TMEM16A expression with immunohistochemical staining.</p><p><b>RESULTS</b>TMEM16A expression was detected in the cytoplasm and cell membrane of the tumor cells. Of the 72 specimens of the tumor tissues, the total positivity rate of TMEM16A expression was 80.56% (58/72), significantly higher than the rate in the adjacent tissues (4.17%, 3/72, P<0.005).</p><p><b>CONCLUSION</b>Aberrant expression of TMEM16A occurs in the majority of gastric carcinoma cases. TMEM16A can be used as a new candidate target for diagnosis and treatment of gastric carcinoma.</p>

Clinicopathologic features and immunophenotypes of CD117-negative gastrointestinal stromal tumor / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the immunophenotype and c-kit or platelet derived growth factor receptor alpha (PDGFRA) gene mutations in CD117-negative gastrointestinal stromal tumors (GISTs).</p><p><b>METHODS</b>Ten cases of GISTs with typical histologic features but no CD117 expression were retrieved from the archival of Department of Pathology, Peking Union Medical College Hospital, China. The cases were further evaluated for the presence of c-kit exons 9, 11, 13 and 17 mutations and PDGFRA exons 12 and 18 mutations. DNA was extracted from the paraffin-embedded tumor tissue. The PCR products were sequenced directly for the mutations. An immunohistochemical study for CD117, CD34, smooth muscle actin, desmin, S-100 protein, WT-1 and DOG-1 was also performed.</p><p><b>RESULTS</b>Eight of the 10 cases had the mutation tests completed. C-kit mutation in exon 9 was detected in only one case. Amongst the 10 cases studied, CD34 was expressed in 9 cases. Smooth muscle actin was focally positive in 2 cases. None of them expressed desmin or S-100 protein. DOG-1 and WT-1 were diffusely positive in 5 and 4 cases, respectively. In addition, DOG1 was diffusely but weakly positive in 1 case and focally expressed in 2 cases. Three cases were focally positive for WT-1.</p><p><b>CONCLUSION</b>Pathologic diagnosis of CD117-negative GISTs can be facilitated with the application of a panel of immunohistochemical markers, including DOG-1 and WT-1.</p>

Expression of DOG-1 in gastrointestinal stromal tumor and its diagnostic application / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the expression of DOG-1 in gastrointestinal stromal tumors (GIST) and its diagnostic application.</p><p><b>METHODS</b>Immunohistochemical EnVision technique was used to assess the expression of DOG-1 in 84 cases of GIST in comparison with CD117 and CD34.</p><p><b>RESULTS</b>All 84 cases of GIST consisted of variable proportions of spindle and epithelioid tumor cells or just one type of the tumor cell. The expression rates of DOG-1, CD117 and CD34 were 91.3% (42/46), 95.7% (44/46) and 82.6% (38/46), in the group of very low and low risk GIST, and were 100% (38/38), 100% (38/38) and 78.9% (30/38), respectively, in the group of moderate and high risk GIST. True leiomyomas, schwannomas, fibromatosis and normal gastrointestinal mucoca did not express these markers. Moreover, the sensitivity and specificity of DOG-1 in the detection of GIST were similar to those of CD117, without statistical difference (P > 0.05) between the two markers. However, the sensitivity and specificity of DOG-1 detection of moderate and high risk GIST were significantly higher than those of CD34 (P < 0.01).</p><p><b>CONCLUSIONS</b>DOG-1 is a novel marker of gastrointestinal stromal tumors. It has the sensitivity and specificity higher than CD34, especially in the detection of moderate and high risk GIST. Combined DOG-1 and CD117 immunohistochemistry will likely improve the diagnostic accuracy of GIST.</p>