Mingzhi Zhang

Six1 Promotes Proliferation of Pancreatic Cancer Cells via Upregulation of Cyclin D1 Expression

Six1 is one of the transcription factors that act as master regulators of development and are frequently dysregulated in cancers. However, the role of Six1 in pancreatic cancer is not clear. Here we show that the relative expression of Six1 mRNA is increased in pancreatic cancer and correlated with advanced tumor stage. In vitro functional assays demonstrate that forced overexpression of Six1 significantly enhances the growth rate and proliferation ability of pancreatic cancer cells. Knockdown of endogenous Six1 decreases the proliferation of these cells dramatically. Furthermore, Six1 promotes the growth of pancreatic cancer cells in a xenograft assay. We also show that the gene encoding cyclin D1 is a direct transcriptional target of Six1 in pancreatic cancer cells. Overexpression of Six1 upregulates cyclin D1 mRNA and protein, and significantly enhances the activity of the cyclin D1 promoter in PANC-1 cells. We demonstrate that Six1 promotes cell cycle progression and proliferation by upregulation of cyclin D1. These data suggest that Six1 is overexpressed in pancreatic cancer and may contribute to the increased cell proliferation through upregulation of cyclin D1.

Role of programmed death ligands in effective T-cell interactions in extranodal natural killer/T-cell lymphoma.

Extranodal natural killer/T-cell lymphoma (ENKL) is marked by a profound cellular immune deficiency that may influence the capacity of T cells to extract an efficient antitumor immune response. It has been confirmed that the B7-CD28 pathway may promote tumor immune evasion by providing a negative regulatory signal. The current study analyzed the expression of programmed death 1 (PD-1)/programmed death ligand (PD-L) in ENKL cell lines and tissues. The functional studies were performed to analyze the functional activity of PD-L1 interacting with effective T cells in ENKL. PD-L1 and PD-L2 mRNA levels in ENKL cell lines were markedly upregulated compared with those in normal natural killer cells. The proteins constitutively expressed in the 30 ENKL specimens were significantly higher than in the 20 rhinitis specimens. In addition, PD-L1 and PD-L2 expression were found to closely correlate with certain clinical histopathological parameters. Furthermore, the count of PD-1+ tumor-infiltrating T lymphocytes was found to negatively correlate with the expression of PD-L1 and PD-L2. The PD-1 expression in the CD4+ and CD8+ T-cell subsets of 20 ENKL patients prior to therapy were significantly higher than that of the 10 healthy volunteers. In the functional studies, the cytokines (interleukin-2 and interferon-γ) secreted by CD8+ T cells were inhibited by PD-L1 expression in SNK-6 cells and this was restored with the presence of the PD-L1 blocking antibody. However no direct effect of PD-L1 was identified on CD8+ T-cell apoptosis and CD8+ T-cell cytotoxicity, as assessed by the proliferation of SNK-6 cells in the presence or absence of the neutralizing anti-PD-L1 antibody. The results of the current study revealed that PD-Ls and PD-1 are aberrantly expressed in ENKL and, furthermore, PD-L1 expression in SNK-6 cells was found to inhibit the activity of CD8+ T-cell cytokine secretion. This indicated that the PD-Ls may prevent effective antitumor immunity in vivo by interacting with tumor T cells, which provides important evidence to delineate the cellular immune deficiency mechanism in ENKL. Therefore, PD-1/PD-Ls are predicted to become novel targets for ENKL immunotherapy.

DDGP versus SMILE in Newly Diagnosed Advanced Natural Killer/T-Cell Lymphoma: A Randomized Controlled, Multicenter, Open-label Study in China.

Purpose: Optimal treatment strategies for advanced natural killer/T (NK/T)-cell lymphoma have not been fully defined. We compared the safety and efficacy of DDGP and SMILE regimens for advanced NK/T-cell lymphoma in a randomized controlled, multicenter, and open-label clinical trial. Experimental Design: Patients were newly diagnosed in stages III–IV and had performance scores in 0 to 2. Six cycles of DDGP (dexamethasone, cisplatin, gemcitabline, and pegaspargase) or SMILE (dexamethasone, methotrexate, ifosfamide, L-asparaginase, and etoposide) chemotherapy were randomly assigned to them. The primary end point was progression-free survival (PFS). Secondary end points included response rate and overall survival (OS). The trial is ongoing and is registered with ClinicalTrials.gov (No. NCT01501149). Results: Of 42 patients enrolled, 21 were treated with DDGP therapy, and 21 patients were treated with SMILE therapy. The 1-year PFS and 2-year OS rates were better in the DDGP group than that in the SMILE group (86% vs. 38% for 1-year PFS, P = 0.006; 74% vs. 45% for 2-year OS, P = 0.027). Complete remission (CR) rate and overall response rate (ORR) of the DDGP group were higher than that in the SMILE group (71% vs. 29%, P = 0.005 for CR rate; 95% vs. 67%, P = 0.018 for ORR). The SMILE group showed more serious leucopenia (P = 0.030) and severe allergic reaction (P = 0.015) than the DDGP group. In addition, two cases in the SMILE group underwent grade 4 mucosal reaction. Conclusions: DDGP chemotherapy resulted in significant improvement in PFS, OS, and better tolerability compared with SMILE chemotherapy for newly diagnosed advanced NK/T-cell lymphoma patients. Clin Cancer Res; 22(21); 5223–8. ©2016 AACR.

TAZ promotes temozolomide resistance by upregulating MCL-1 in human glioma cells.

Temozolomide is a novel cytotoxic agent currently used as first-line chemotherapy for glioblastoma multiforme (GBM). However, intrinsic or acquired chemoresistance to temozolomide remains the greatest obstacle to the successful treatment of human GBM. The principal mechanism responsible for this resistance is largely unknown. In the present study, we showed that expression of transcriptional co-activator with PDZ-binding motif (TAZ) in glioma cells correlated with temozolomide chemoresistance in human glioma cells. Overexpression of TAZ promoted temozolomide resistance in U-87MG cells, whereas knockdown of TAZ expression sensitized temozolomide-resistant U-251MG cells to temozolomide. Further, TAZ inhibits temozolomide induced apoptosis via upregulation of MCL-1 (myeloid cell leukemia 1) and high expression of TAZ predicts a poor prognosis for GBM patients. In conclusion, our results suggest that TAZ had a critical role in the resistance to temozolomide in glioma cells, and it may provide a promising target for improving the therapeutic outcome of temozolomide-resistant gliomas.

Six1 mediates resistance to paclitaxel in breast cancer cells.

Paclitaxel resistance remains a major challenge in the treatment of breast cancer. Six1 is a homeodomain-containing transcription factor invloved in the initiation, progression and metastasis of breast cancer. We herein investigate the relationship between Six1 and resistance of paclitaxel in this study. The results indicate that six1 is a mediator of the paclitaxel resistance in breast cancer. The expression level of Six1 in breast cancer cells correlates with their resistance to paclitaxel. On the one hand, forced overexpression of Six1 in Six1-low/paclitaxel-sensitive MCF-7 or HS578T breast cancer cells induce their resistance to paclitaxel treatment directly; On the other hand, knockdown of endogenous Six1 in Six1-high/drug-resistant BT-474 breast cancer cells sensitized these cells to paclitaxel treatment. Besides, Six1 overexpression confers resistance to paclitaxel-mediated apoptosis in breast cancer cells. Furthermore, clinical data and the publicly available breast cancer gene expression datasets display that the association of Six1 expression with paclitaxel sensitivity is clinically relevant. In conclusion, these data suggest that Six1 may function as an important modifier of the paclitaxel response in breast cancer cells, and serve as a potential target for overcoming paclitaxel resistance in breast cancer.

Application of mitochondrial pyruvate carrier blocker UK5099 creates metabolic reprogram and greater stem-like properties in LnCap prostate cancer cells in vitro

Aerobic glycolysis is one of the important hallmarks of cancer cells and eukaryotic cells. In this study, we have investigated the relationship between blocking mitochondrial pyruvate carrier (MPC) with UK5099 and the metabolic alteration as well as stemness phenotype of prostatic cancer cells. It was found that blocking pyruvate transportation into mitochondrial attenuated mitochondrial oxidative phosphorylation (OXPHOS) and increased glycolysis. The UK5099 treated cells showed significantly higher proportion of side population (SP) fraction and expressed higher levels of stemness markers Oct3/4 and Nanog. Chemosensitivity examinations revealed that the UK5099 treated cells became more resistant to chemotherapy compared to the non-treated cells. These results demonstrate probably an intimate connection between metabolic reprogram and stem-like phenotype of LnCap cells in vitro. We propose that MPC blocker (UK5099) application may be an ideal model for Warburg effect studies, since it attenuates mitochondrial OXPHOS and increases aerobic glycolysis, a phenomenon typically reflected in the Warburg effect. We conclude that impaired mitochondrial OXPHOS and upregulated glycolysis are related with stem-like phenotype shift in prostatic cancer cells.

Follicular dendritic cell sarcoma of the pharyngeal region

Follicular dendritic cell sarcoma (FDCS) is a rare neoplasm arising most commonly from follicular dendritic cells in the lymph nodes. It is exceedingly rare in extranodal sites, particularly in the pharyngeal region. The present study reports 3 cases occurring in the pharyngeal region. Case 1 had tonsil and cervical lymph node involvement, while case 3 also had tonsil involvement. Cases 1 and 3 relapsed locally at 3 and 17 months after surgery, respectively. Case 2 was diagnosed with a tumor in the parapharyngeal space and the patient succumbed to the disease 5 months after treatment with combined surgery and chemotherapy. All 3 cases were misdiagnosed initially. Pathological biopsy examination, including histopathology and immunohistochemistry, was essential for diagnosis. The data for 52 cases, including cases from the literature and the present cases, were analyzed. The results indicated that 57% (26/46) of the initial diagnoses were inaccurate, while the recurrence, metastasis and mortality rates were 40, 16 and 10%, respectively. The statistics supported the theory that FDCS of the pharyngeal region is a low-grade sarcoma. Involvement of the tonsils (52%, 27/52) and parapharyngeal space (19%, 10/52) were observed most commonly, while FDCS at various sites showed different prognoses. The various survival rates were calculated in the present study. The large tumors (≥4 cm) had a poorer prognosis than the small tumors (<4 cm; P<0.05). Among the 50 cases with available follow-up data, 46% (23/50) were treated with surgery alone, 52% (26/50) with combination therapy (surgery followed by chemotherapy and/or radiotherapy) and 2% (1/50) with surveillance. There was no statistically significant evidence (P>0.05) that combination therapy improves survival rates, compared with surgery alone.

Clinical features and treatment of natural killer/T cell lymphoma associated with hemophagocytic syndrome: comparison with other T cell lymphoma associated with hemophagocytic syndrome.

Abstract Natural killer (NK)/T cell lymphoma associated with hemophagocytic syndrome (NK/T-LAHS) is a rare and life-threatening disease. The clinical features and overall survival of NK/T cell and other T cell lymphomas associated with hemophagocytic syndrome remain uncertain. We retrospectively reviewed the clinical records of 15 patients with NK/T-LAHS and 14 patients with other T-LAHS from December 2008 to June 2013. Patients with NK/T cell lymphoma had a higher International Prognostic Index (p = 0.045) and were more likely to be positive for Epstein–Barr virus (p = 0.025) than those with T cell lymphoma. The level of aspartate aminotransferase (AST) was significantly higher than that of alanine aminotransferase (ALT) in the NK/T-LAHS group (p = 0.005), as well as in the T-LAHS group (p = 0.019). The level of direct bilirubin (DBIL) was more likely to be elevated than that of indirect bilirubin (IBIL) in patients with NK/ T-LAHS (p = 0.047), while there was no significant difference in the T-LAHS group (p = 0.124). The median survival time for patients with NK/T and T cell lymphoma was 28 and 33 days, respectively (p = 0.726). However, in the NK/T-LAHS group, the median survival time of patients treated with and without pegaspargase was 116 and 15 days, respectively (p = 0.003). Our results suggest that patients with NK/T-LAHS are at higher risk and suffer a worse prognosis. However, the use of pegaspargase could benefit patients and lead to long-term overall survival.

ILs-3, 6 and 11 increase, but ILs-10 and 24 decrease stemness of human prostate cancer cells in vitro.

Cancer stem cells (CSCs) are associated with cancer recurrence and metastasis. Prostate cancer cells often metastasize to the bone with a complex microenvironment of cytokines favoring cell survival. In this study, the cell stemness influence of a group of interleukins including IL-3, 6, 10, 11 and 24 on human prostate cancer cell lines LNCaP and PC-3 was explored in vitro. Sulforhodamine B(SRB) and 5-ethynyl-2′-deoxyuridine (EdU) assays were applied to examine the effect on cell proliferation, and wound healing and transwell assays were used for migration and invasion studies, in addition to colony formation, Western blotting and flowcytometry for the expression of stemness factors and chemotherapy sensitivity. We observed that ILs-3, 6 and 11 stimulated while ILs-10 and 24 inhibited the growth, invasion and migration of both cell lines. Interestingly, ILs-3, 6 and 11 significantly promoted colony formation and increased the expression of SOX2, CD44 and ABCG2 in both prostate cancer cell lines. However, ILs-10 and 24 showed the opposite effect on the expression of these factors. In line with the above findings, treatment with either IL-3 or IL-6 or IL-11 decreased the chemosensitivity to docetaxel while treatment with either IL-10 or IL-24 increased the sensitivity of docetaxel chemotherapy. In conclusion, our results suggest that ILs-3, 6 and 11 function as tumor promoters while ILs-10 and 24 function as tumor suppressors in the prostate cancer cell lines PC-3 and LNCaP in vitro, and such differences may attribute to their different effect on the stemness of PCa cells.

Epidemiological and clinical characteristics of the outbreak of 2009 pandemic influenza A (H1N1) at a middle school in Luoyang, China

OBJECTIVES To describe the epidemiological and clinical characteristics of 2009 H1N1 influenza, particularly the incubation period and the duration of symptoms, and to assess the public health response to this outbreak. STUDY DESIGN A retrospective cohort study was conducted among all students and employees in a middle school by telephone survey and laboratory inspection. METHODS Nasopharyngeal specimens were collected and tested, and real-time reverse transcriptase polymerase chain reaction testing was performed to confirm the viral infection. The epidemiological and clinical characteristics were obtained through a telephone survey, and the incubation period and the duration of symptoms associated with 2009 H1N1 influenza were estimated by parametric distribution. RESULTS In total, 253 cases of influenza-like illness were found among students and employees, and 79 of these cases were confirmed as H1N1 infection through laboratory inspection. The response rate for the telephone survey was 93.48% for the students (2586/2768) and 85.87% for the employees (158/184). The average attack rate was 9.22% (253/2744). The main reported symptoms were fever (100%), cough (74.68%), sore throat (59.49%), headache (56.96%) and myalgia/arthralgia (51.90%). No complications were reported and no deaths occurred. The confirmed and suspected cases had no associated travel history or contact with a confirmed or probable case. The estimated median incubation period was 1.6 days [95% confidence interval (CI) 1.2-2.3]. The duration of symptoms was 3-11 days, and the median duration of symptoms was 7.5 days (95% CI 4.5-10.5). CONCLUSIONS The results suggest that the outbreak of 2009 H1N1 influenza in this middle school was widespread but not severe. The natural history of 2009 H1N1 influenza virus appears to be similar to that of previously circulating pandemic and interpandemic influenza viruses. The public health response indicates that school closure could have a substantial impact on the spread of 2009 H1N1 influenza.