Effects of hypoxia on adiponectin in tongue squamous cell carcinoma / 中国肿瘤临床

Objective: Adiponectin (APN) is an endogenous cytokine that mediates the development and progression of various tumors through its receptors (AdipoRs). The present study aimed to detect the expression and distribution of APN and its receptors (AdipoR1 and AdipoR2) in tongue squamous cell carcinoma (TSCC). Moreover, we explored whether the locoregional expression of APN was reg-ulated by HIF-1α in the hypoxic microenvironment. Methods: The expression and distribution of APN and its receptors in TSCC tissues were analyzed by immunohistochemical. Lentiviral expression vector for HIF-1α shRNA was constructed and stably transfected in TSCC cells to knock down HIF-1α expression. The mRNA and protein expression levels of APN and its receptors were detected using RT-PCR and Western blot, respectively, after hypoxic treatment. Results: The locoregional expression of APN and AdipoR1, but not AdipoR2, was upregulated at the early stages of T1, T2, and/or N0 stage, respectively, in tumor tissues compared to that in control paracancer-ous tissues (P<0.05 or P<0.01). The expression of APN and AdipoR1, but not AdipoR2, in TSCC cells was up-regulated on hypoxic treat-ment. Moreover, the expression of APN and AdipoR1 was down-regulated after shRNA knockdown of HIF-1α under hypoxia. Conclu-sions: The APN-AdipoR1 signaling pathway was activated and regulated by HIF-1α in the hypoxic environment of TSCC tissues.

Regulation of myostatin promoter activity by myocyte enhancer factor 2 / 生物工程学报

Myostatin (Mstn) is a member of the transforming growth factor-beta superfamily that functions as a negative regulator of skeletal muscle growth and differentiation in mammals. The transcriptional regulation of Mstn is controlled by multiple genes including MEF2, which raise the importance of identifying the binding sites of MEF2 on myostatin promoter region and mechanisms underlying. In this study, we investigated the transcriptional regulation of MEF2 on porcine Mstn promoter activity in C2C12 cells. Sequence analysis of the 1 969 bp porcine Mstn promoter region revealed that it contained three potential MEF2 motifs. Using a serial deletion strategy, we tested the activity of several promoter fragments by luciferase assay. Overexpression of MEF2C, but not MEF2A increased Mstn promoter activity in all the promoter fragments with MEF2 motifs by two to six folds, in both C2C12 myoblasts and myotubes. When we transfected exogenous MEF2C, Mstn mRNA level was also upregulated in C2C12 cells, but the protein level was only significantly increased in myotubes. Thus, we propose that MEF2C could modulate and restrain myogenesis by Mstn activation and Mstn-dependent gene processing in porcine. Our research also provided potential targets and an effective molecule to regulate Mstn expression and gave a new way to explore the functional performance of Mstn.

Over-expression of phospholipase D3 inhibits Akt phosphorylation in C2C12 myoblasts / 生物工程学报

Phospholipase D (PLD) hydrolyzes phosphocholine into choline and phosphatide acid, and these metabolites play an important role in regulating cell physiology and biochemistry. To study the biological function of phospholipase D3 (PLD3) during the insulin stimulation in C2C12 myoblasts, we constructed PLD3 over-expressed cell lines (C2C12/pPLD3) and investigated the phosphorylation of Akt. The results showed that the level of phosphorylated Akt (P-Akt) was significantly increased in control C2C12 cells when insulin concentration was elevated during cell treatment, whereas the level of P-Akt in C2C12/pPLD3 cells was not changed. When extending the time of insulin treatment, P-Akt level in C2C12/pPLD3 cells was increased around 2 folds, but the total level of P-Akt in C2C12/pPLD3 was still lower than that in control group. 1-Butanol, a PLD inhibitor, could completely block Akt phosphorylation in C2C12 cells that even stimulated by insulin. However, 1-Butanol did not inhibit the Akt phosphorylation in C2C12/pPLD3 cells, but increased the phosphorylation up to 6 folds higher than control cells. The level of Akt phosphorylation in control C2C12 cells was increased significantly when stimulated by phosphatidic acid (PA), while there was no change in C2C12/pPLD3 cells with the similar treatment. When cells simulated by both PA and insulin, P-Akt level in both C2C12/pPLD3 cells and C2C12 cells were down regulated. Our observations indicated that PLD3 over expression may inhibit Akt phosphorylation and further block the transduction of insulin signaling in C2C12 cells.

Report on skin-sparing mastectomy with immediate breast reconstruction in 15 cases / 中国组织工程研究

BACKGROUND: Recently the prevalence rate of mass in mammary gland increases significantly than before. To use which kind of technology is not only related with the post-operation recurrence, but also related with the reconstruction of their confidence. Therefore, how to reduce the trauma physically and psychologically in patients to the maximal degree has become the chief factor to choose technology by surgeons.OBJECTIVE: To observe the effects of transverse rectus abdominis musculocutaneous (TRAM) flap, latissimus dorsi musculocutaneous flap with breast prothesis, local flap and simple breast prothesis after skin-sparing mastectomy with immediate breast reconstruction.DESIGN: Case analysis.SETTING: Department of Plastic Surgery, Shenzhen People's Hospital,Second Clinical Medical College of Jinan University.PARTICIPANTS: A total of 15 ductal carcinoma in situ (DCIS) and huge breast benign tumor patients were enrolled into Shenzhen People's Hospital between October 1997 and May 2004, aged from 20 to 46 years. They all got disease in single breast, and 8 of them had preoperative diagnosis of DCIS, T1N0M0 and 7 of them had huge breast benign tumor. Operation program was informed to the patients before operation so as to gain their agreement.METHODS: Skin-sparing mastectomy was performed with circular shape incision at areola and using TRAM flap, latissimus dorsi musculocutaneous flap with breast prothesis, local flap and simple breast prothesis to fill breast. Slight skin of musculo-cutaneous flap could compensate the nipple and areola when performing reconstruction. At the reoperation, nipple was made at the transferred flap.MAIN OUTCOME MEASURES: To observe the patients with or without recurrence or transfer after operation and local healing of wound.RESULTS: With the cooperation of general surgeons the operation was done in 15 cases and 14 cases of them were followed up for more than 1 year. The reconstructed breasts were with good symmetry with the opposite one, normal skin sensation, natural shape and inconspicuous scar.CONCLUSION: This is an excellent alternative method for mastectomy and breast reconstruction based on the avoidance of recurrence of breast cancer in severe operation.