Xiaoyin Zhang

Zinc ribbon domain-containing 1 (ZNRD1) mediates multidrug resistance of leukemia cells through regulation of P-glycoprotein and Bcl-2

Here, we investigated the role of zinc ribbon domain-containing 1 (ZNRD1) in multidrug resistance (MDR) of leukemia cells and the possible underlying mechanisms. ZNRD1 was found overexpressed in the vincristine-induced MDR leukemia cell HL-60/vincristine moreso than its parental cell HL-60. Up-regulation of ZNRD1 expression could confer resistance of both P-glycoprotein (P-gp)-related and P-gp-nonrelated drugs on HL-60 cells and suppress Adriamycin-induced apoptosis accompanied by decreased accumulation and increased releasing amount of Adriamycin. ZNRD1 could significantly up-regulate the expression of P-gp, Bcl-2, and the transcription of the MDR1 gene but not alter the expression of MDR-associated protein, glutathione S-transferase activity, or intracellular glutathione content in leukemia cells. In addition, inhibition of ZNRD1 expression by RNA interference or P-gp inhibitor could partially reverse ZNRD1-mediated MDR. The further study of the biological functions of ZNRD1 may be helpful for understanding the mechanisms of MDR of leukemia and developing possible strategies to treat leukemia. [Mol Cancer Ther 2005;4(12):1936–42]

Controlled trials in hepatitis B virus-related decompensate liver cirrhosis: peripheral blood monocyte transplant versus granulocyte–colony-stimulating factor mobilization therapy

BACKGROUND Liver cirrhosis represents the end stage of chronic liver injury. Currently, liver transplantation provides the only definite cure but it is beset with many problems, including lack of donors and risk of rejection. Stem cell therapy is very attractive in this setting because it has the potential to help tissue regeneration. In this study, we aimed to investigate the therapeutic effect of peripheral blood monocyte cell (PBMC) transplantation in decompensated liver cirrhosis. METHODS A total of 40 subjects (31 men and nine females, age range 21-71 years) was recruited to two groups. Group 1 received granulocyte-colony-stimulating factor (G-CSF) mobilization, PBMC collection by leukapheresis and PBMC transplant therapy. Group 2 received G-CSF mobilization for 4 days. At baseline and 6 months after treatment, liver function of the two groups was monitored by blood examination and ultrasonagraphy. RESULTS Both groups gained significant improvement in liver synthetic function, such as serum albumin and prothrombin time, from baseline to 6 months after treatment (P<0.01). However, there was no significant difference in alanine aminotransferase, aspartate aminotransferase and total bilirubin in both groups (P>0.05). Compared with group 2, a significantly improved liver function was observed in group 1, including elevated serum albumin level and a decreased CTP score (P<0.05). No major adverse effects were noted. DISCUSSION Autologous PBMC transplantation could be considered as a novel and alternative treatment for patients with decompensated liver cirrhosis.

Preparation and Characterization of a Novel Monoclonal Antibody Specific to Human ZNRD1 Protein

We have efficiently generated the first monoclonal antibody (MAb) against the human ZNRD1 protein, a transcription-associated protein, consisting of two zinc ribbon domains. Hybridomas were screened by indirect enzyme-linked immunosorbent assay (ELISA) using either purified 6 x His-ZNRD1fusion protein or purified 6 x His-OS-9 fusion protein as a control. One MAb named H6 (IgG(1)), effective in detecting the recombinant and cellular protein, was characterized by ELISA and Western immunoblotting. Thus, it binds to native ZNRD1 protein and should be useful in studies of ZNRD1 protein function and expression. By Western immunoblotting analysis of 16 patients with gastric cancer using the MAb, we found ZNRD1 protein was more overexpressed in incision margin than in carcinoma tissue. The results showed that ZNRD1 might be a novel modifier in gastric carcinogenesis.

Reversal of multidrug resistance of vincristine-resistant gastric adenocarcinoma cells through up-regulation of DARPP-32

Here we investigated the roles of DARPP‐32 in multidrug resistance (MDR) of gastric cancer cells and the possible underlying mechanisms. We constructed the eukaryotic expression vector of DARPP‐32 and transfected it into human vincristine‐resistant gastric adenocarcinoma cell line SGC7901/VCR. Up‐regulation of DARPP‐32 could significantly enhance the sensitivity of SGC7901/VCR cells towards vincristine, adriamycin, 5‐fluorouracil and cisplatin, and could decrease the capacity of cells to efflux adriamycin. Whats more, the results of subrenal capsule assay confirmed that DARPP‐32 might play a certain role in MDR of gastric cancer. DARPP‐32 could significantly down‐regulate the expression of P‐gp and zinc ribbon domain‐containing 1 (ZNRD1), but not alter the expression of multidrug resistance‐associated protein (MRP) or the glutathione S‐transferase (GST). DARPP‐32 could also significantly decrease the anti‐apoptotic activity of SGC7901/VCR cells. Further study of the biological functions of DARPP‐32 might be helpful for understanding the mechanisms of MDR in gastric cancer.

Comparison of Endoscopic and Open Resection for Small Gastric Gastrointestinal Stromal Tumor.

The National Comprehensive Cancer Network recommends conservative follow-up for gastric gastrointestinal stromal tumors (GISTs) less than 2 cm. We have previously reported that the mitotic index of 22.22% of small gastric GISTs exceeded 5 per 50 high-power fields and recommended that all small gastric GISTs should be resected once diagnosed. The aim of the present study is to compare the safety and outcomes of endoscopic and open resection of small gastric GISTs. From May 2010 to March 2014, a total of 90 small gastric GIST patients were enrolled in the present study, including 40 patients who underwent surgical resection and 50 patients who underwent endoscopic resection. The clinicopathological characteristics, resection-related factors, and clinical outcomes were recorded and analyzed. The clinicopathological characteristics were comparable between the two groups except for tumor location and DOG-1 expression. Compared with the surgical resection group, the operation time was shorter (P = .000), blood loss was less (P = .000), pain intensity was lower (P < .05), duration of first flatus and defecation was shorter (P < .05), and medical cost of hospitalization was lower (P = .027) in the endoscopic resection group. The complications and postoperative hospital stay were comparable between the two groups. No in situ recurrence or liver metastasis was observed during follow-up. Endoscopic resection of small gastric GISTs is safe and feasible compared with surgical resection, although perforation could not be totally avoided during and after resection. The clinical outcome of endoscopic resection is also favorable.

Reversal of Multidrug Resistance of Adriamycin-resistant Gastric Adenocarcinoma Cells Through the Up-regulation of DARPP-32

We have investigated the roles of dopamine and cAMP-regulated phosphoprotein (DARPP-32) in the multidrug resistance (MDR) of gastric cancer cells and the possible underlying mechanisms. The up-regulation of DARPP-32 was found to significantly enhance the sensitivity of cells of human adriamycin (ADR)-resistant gastric adenocarcinoma cell line SGC7901/ADR to vincristine, ADR, 5-fludrouracil and cisplatin. The results of an in vivo drug sensitivity assay confirmed that DARPP-32 may play a specific role in the MDR of gastric cancer. DARPP-32 significantly down-regulated the expression of P-glycoprotein and zinc ribbon domain-containing 1 (ZNRD1), but did not alter the expression of MDR-associated protein or glutathione-S-transferase. The up-regulation of ZNRD1 significantly inhibited the drug sensitivity of gastric cancer cells over-expressing DARPP-32, indicating that ZNRD1 may be important in the DARPP-32-mediated MDR of gastric cancer. DARPP-32 was also able to significantly decrease the anti-apoptotic activity of SGC7901/ADR cells. Further study of the biological functions of DARPP-32 may be helpful for understanding the mechanisms of MDR of gastric cancer cells and developing possible strategies to treat gastric cancer.

Function of PrPC (1-OPRD) in biological activities of gastric cancer cell lines.

Approximately 10–15% of the human prion disease is inherited and one of the important genetic mutations occurs in the octapeptide repeat region of prion protein gene. One of the variants, one octapeptide repeat deletion (1‐OPRD), existed in several gastric cancer cell lines and its mutation frequency was higher in gastric cancer cases. However, the biological functions of it remain unknown. Wild‐type and mutation forms of PrPC were cloned and transfected into gastric cancer cells. Cell apoptosis, adhesion, invasion, multidrug resistance (MDR) and proliferation were, respectively, investigated. Different expressed genes were screened by gene array and proved by PT‐PCR. Further, luciferase report assay was used to explore the transcriptional activation of target genes. Forced overexpression PrPC (1‐OPRD) could promote the gastric cancer cells SGC7901 growth through facilitating G1‐ to S‐phase transition in the cell cycle. PrPC (1‐OPRD) could also inhibit apoptosis, and promote adhesion, invasion and MDR in SGC7901. However, it exhibited no significant difference between wild‐type PrPC (1‐OPRD) and PrPC on apoptosis, invasion or MDR effects. Further experiments indicated that PrPC (1‐OPRD) could trigger the transactivation of cyclinD3 besides cyclinD1 to promote cell transition and proliferation. Overexpression of PrPC (1‐OPRD) might promote the proliferation of gastric cancer cells at least partially through transcriptional activation of cyclinD3 to accelerate the G1‐/S‐phase transition. The promoting proliferation effect of PrPC (1‐OPRD) was more than that of wild‐type PrPC. However, they showed no difference on apoptosis, adhesion, invasion or MDR effects of gastric cancer cells.

DARPP-32 Mediates Multidrug Resistance of Gastric Cancer Through Regulation of P-gp and ZNRD1

Here, we firstly investigated the roles of DARPP-32 in multidrug resistance of gastric cancer cells. Inhibition of DARPP-32 by small interfering RNA led to decreased sensitivity of cells to chemotherapeutic drugs, accompanied by increased capacity of cells to efflux adriamycin. Inhibition of DARPP-32 expression could significantly up-regulate the expression of permeability glycoprotein (P-gp) and zinc ribbon domain-containing 1 (ZNRD1), but not alter the expression of multidrug resistance-associated protein or glutathione stransferase. The DARPP-32 siRNA-mediated MDR could be reversed by inhibitor of P-gp or siRNA of ZNRD1, indicating DARPP-32 might mediate MDR of gastric cancer through regulation of P-gp and ZNRD1.

Efficient induction of specific cytotoxic T lymphocytes against gastric adenocarcinoma by a survivin peptide

Survivin has been demonstrated to be an excellent target for immunotherapy in several types of cancer, but little is known of the efficacy of survivin with gastric adenocarcinoma. In this study, a simple method was performed, and relatively high efficacy was shown upon inducing survivin-derived peptide-specific cytotoxic T lymphocytes (CTL) from peripheral blood mononuclear cells of healthy donors. The induced CTLs exhibited specific lysisagainstHLA-A2 matched tumor cells in vitro, and similar results were demonstrated in primary cell cultures isolated from patients with gastric adenocarcinoma. Up to 30% of randomly selected patients could potentially benefit from immunotherapy targeting survivin. These results suggested that this survivin epitope peptide could be a promising vaccine candidate for immunotherapy for patients with gastric adenocarcinoma.

Up-regulation of NOB1 in esophageal squamous cell carcinoma

We have efficiently generated the first monoclonal antibody specific to the human NOB1 protein, which was assumed to be a transcription-associated protein. Hybridomas were screened by indirect enzyme-linked immunosorbent assay (ELISA) using either purified 6 × His-NOB1 fusion protein or purified 6 × His-ZNRD1 fusion protein as controls. One MAb named H5 (IgG1) effective in detecting the recombinant and the cellular protein of NOB1 was characterized by ELISA and Western immunoblotting. By immunohistochemical analysis, NOB1 protein was found up-regulated in esophageal squamous cell carcinoma (SCC), compared with normal esophageal tissues. The expression of NOB1 was statistically correlated with the differentiation of SCC. In conclusion, NOB1 might be a novel modifier in the carcinogenesis of SCC.The following article from Diseases of the Esophagus “Up-regulation of NOB1 in esophageal squamous cell carcinoma” by L. Hong, Y. Zhao, L. Yan, X. Zhou, X. Zhang, W. Guo, L. Sun, J. Wang, H. Jin, J. Ding, K. Wu and D. Fan, published online 19 October 2007, has been retracted by agreement among the authors, the journal Editor-in-Chief Claude Deschamps, and Wiley-Blackwell as the authors determined there were inconsistencies with the original data found on further experiments.