Impact of GFRA1 gene reactivation by DNA demethylation on prognosis of patients with metastatic colon cancer

BACKGROUND The expression of the membrane receptor protein GFRA1 is frequently upregulated in many cancers,which can promote cancer development by activating the classic RET-RAS-ERK and RET-RAS-PI3K-AKT pathways.Several therapeutic anti-GFRA1 antibody-drug conjugates are under development.Demethylation(or hypomethylation)of GFRA1 CpG islands(dmGFRA1)is associated with increased gene expression and metastasis risk of gastric cancer.However,it is unknown whether dmGFRA1 affects the metastasis of other cancers,including colon cancer(CC).AIM To study whether dmGFRA1 is a driver for CC metastasis and GFRA1 is a potential therapeutic target.METHODS CC and paired surgical margin tissue samples from 144 inpatients and normal colon mucosal biopsies from 21 noncancer patients were included in this study.The methylation status of GFRA1 islands was determined by MethyLight and denaturing high-performance liquid chromatography and bisulfite-sequencing.Kaplan-Meier analysis was used to explore the effect of dmGFRA1 on the survival of CC patients.Impacts of GFRA1 on CC cell proliferation and migration were evaluated by a battery of biological assays in vitro and in vivo.The phosphorylation of AKT and ERK proteins was examined by Western blot analysis.RESULTS The proportion of dmGFRA1 in CC,surgical margin,and normal colon tissues by MethyLight was 68.4%,73.4%,and 35.9%(median;nonparametric test,P=0.001 and<0.001),respectively.Using the median value of dmGFRA1 peak area proportion as the cutoff,the proportion of dmGFRA1-high samples was much higher in poorly differentiated CC samples than in moderately or welldifferentiated samples(92.3%%vs 55.8%,Chi-square test,P=0.002)and significantly higher in CC samples with distant metastasis than in samples without(77.8%vs 46.0%,P=0.021).The overall survival of patients with dmGFRA1-low CC was significantly longer than that of patients with dmGFRA1-high CC(adjusted hazard ratio=0.49,95%confidence interval:0.24-0.98),especially for 89 CC patients with metastatic CC(adjusted hazard ratio=0.41,95%confidence interval:0.18-0.91).These data were confirmed by the mining results from TCGA datasets.Furthermore,GFRA1 overexpression significantly promoted the proliferation/invasion of RKO and HCT116 cells and the growth of RKO cells in nude mice but did not affect their migration.GFRA1 overexpression markedly increased the phosphorylation levels of AKT and ERK proteins,two key molecules in two classic GFRA1 downstream pathways.CONCLUSION GFRA1 expression is frequently reactivated by DNA demethylation in CC tissues and is significantly associated with a poor prognosis in patients with CC,especially those with metastatic CC.GFRA1 can promote the proliferation/growth of CC cells,probably by the activation of AKT and ERK pathways.GFRA1 might be a therapeutic target for CC patients,especially those with metastatic potential.

DETECTION AND SIGNIFICANCE OF HBV IN RENAL TISSUE OF HBV ASSOCIATED GLOMERULONEPHRITIS PATIENTS

Objective To study the pathogenesis of hepatitis B virus ( HBV ) on kidney tissues. Methods HBsAg and HBcAg in paraffin-embedded renal biopsy tissues from 27 cases of glomerulonephritis with positive serum HBV markers were observed by using immunohistochemistry. In addition, in situ polymerse chain reaction (IS-PCR) was performed in 5 cases with positive HBsAg and HBcAg in renal tissue of the 27-case glomerulonephritis to reveal the state of renal HBV DNA. Results Twenty cases (20/27,74.07%) were positive with HBAg which were mainly diffusely distributed in epithelial cells of renal tubule. Four cases (4/5,80% ) were positive with HBV DNA whose distribution was the same of that of HBAg. Conclusion Renal lesions due to HBV are not only the results of immunologic response, but also the outcome of direct invasion and duplication of HBV in epithelial cells of renal tubule.

THE STUDY ON RELATION BETWEEN CD1a^+ CELLS AND INFILTRATIVE CD3 ^+ AND CD8 ~ + CELLS IN RENAL TISSUE OF GLOMERULONEPHRITIS

Objective To discuss the role of dendritic cell s (DCs) in cellular immunity pathogenesis of glomerulonephritis (GN). Meth ods 114 patients with GN were selected randomly and divided into two gr oups, primary GN (pGN) and secondry GN (sGN). CD1a +, CD3 + and CD8 + cells in bioptic renal tissues were examined immunohistochemically. The di stribution of CD1a + cells and the infiltration of CD3 + and CD8 + cells in renal tissues were observed. Results There was no si gnificant difference of CD1a +, CD3 +, and CD8 + cells between pG N and sGN group (P>0.05). CD1a + cells had significant positive correla tion with the infiltrative CD3 + and CD8 + cells, respectively (P< 0.01). The infiltrative CD3 + cells had significant positive correlation wi th the CD8 + cells in the same area, respectively (P<0.01). CD1a + cells, CD3 + cells infiltrating in both glomeruli and renal interstitial t issues, and CD8 + cells only infiltrating in renal interstitial tissues, al l of them had significant positive correlation with the degree of glomerular pro liferation, respectively (P<0.05). The infiltrative CD3 + and CD8 + cells in renal interstitial tissues had significant positive correlation with the degree of glomerular sclerosis and the lesion degree of renal tubule and in terstitial, respectively (P<0.05). There were significant positive correlati on between CD1a + cells and the lesion degree of renal interstitial (P< 0.05). Conclusion DCs could activate T lymphocyte by presenting antigen, then the activated T lymphocyte participate in the pathogenesis of GN through releasing cytokine and/or directly damaging the renal tubule and interst itial, which produce more serious glomerular lesion.

Effect of Liuweibuqi capsule, a Chinese patent medicine, on the JAK1/STAT3 pathway and MMP9/TIMP1 in a chronic obstructive pulmonary disease rat model

OBJECTIVE： To observe effect of Liuweibuqi Capsule, a Traditional Chinese Medicine （TCM）, on the janus kinase （JAK）/signal transducer and activator of transcription （STAT） pathway and matrix metalloproteinases （MMPs） in a chronic obstructive pulmonary disease （COPD） rat model with lung deficiency in terms of TCM＇s pattern differentiation. METHODS： Rats were randomly divided into a normal group, model group, Liuweibuqi group, Jinshuibao group, and spleen aminopeptidase group （n= 10）. Aside from the normal group, all rats were ex-posed to smoke plus lipopolysaccharide tracheal instillation to establish the COPD model with lung deficiency. Models were established after 28 days and then the normal and model groups were given normal saline （0.09 g/kg）, Liuweibuqi group was given Liuweibuqi capsule （0.35 g/kg）, Jinshuibao group was given Jinshuibao capsules （0.495 g/kg）, and the spleen group was given spleen aminopeptidase （0.33 mg/kg）, once a day for 30 days. Changes in symptoms, signs, and lung histology were observed. Lung function was measured with a spirometer. Serum cytokines were detected using enzyme-linked immunosorbent assay, and changes in the JAK/STAT pathway, MMP-9, and MMPs inhibitor 1 （TIMP1） were detected by immunohistochemistry, RT-PCR, and western blotting, respectively.RESULTS： Compared with the normal group, lung tissue was damaged, and lung function was reduced in the model control group. Additionally, the levels of interleukin （IL）-1β, y interferon （IFN-γ）, and IL-6 were higher, while IL-4 and IL-10 were lower in the model control group than those in the normal group. The expressions of JAK1, STAT3, ρ-STAT3, and MMP-9 mRNA and protein in lung tissue were higher, and TIMP1 mRNA and protein was lower in the model group compared with the normal group. After treatment, compared with the model group, the expression of inflammatory cytokines was lower in each treatment group, and expressions of JAK/ STAT pathway, MMPs were lower. Compared with the positive control groups, the Jinshuibao and spleen aminopeptidase groups, lung function was better, and JAK1, STAT3, and p-STAT3 protein were lower and TIMP1 was higher in the Liuweibuqi group.CONCLUSION： Liuweibuqi capsules can improve the symptoms of COPD possibly by regulating the expression of the JAK1/STAT3 pathway and MMP9/ TIMP1.