Selective suppression of the JNK-MMP2/9 signal pathway by tetramethylpyrazine attenuates neuropathic pain in rats.

BACKGROUND: Activated astrocytes release matrix metalloproteinase-2/9 (MMP-2/9) to induce central sensitization and maintain neuropathic pain. However, the mechanisms involved in the activation of MMP-2/9 on astrocytes during pain remain poorly understood. Meanwhile, there is a lack of effective treatment to inhibit the activation of MMP-2/9 on astrocytes. In this study, we aim to investigate the effect of tetramethylpyrazine (TMP), a natural compound with analgesic effects but unknown mechanisms, on MMP-2/9 in neuropathic pain. METHODS: The nociception was assessed by measuring the incidence of foot withdrawal in response to mechanical indentation in rats (n = 6). Cell signaling was assayed using western blotting (n = 6) and immunohistochemistry (n = 5). The astrocyte cell line C8-D1A was cultured to investigate the in vitro effects. RESULTS: TMP significantly attenuated the maintenance of chronic constrictive injury (CCI)-induced neuropathic pain, inhibited the activation of astrocytes, and decreased the expression of MMP-2/9. Furthermore, our results indicated that TMP could selectively suppress JNK activity but had no notable effects on ERK and p38. Our study also revealed that the effect of TMP may be dependent on the inhibition of TAK1. CONCLUSIONS: Inhibition of astrocyte activation in the spinal cord by tetramethylpyrazine may have utility in the treatment of CCI-induced neuroinflammation, and our results further implicate JNK-MMP-2/9 as a novel target for the attenuation of neuropathic pain.

Genetic variants at 6p21.1 and 7p15.3 Identified by GWASs of multiple cancers and ovarian cancer risk: a case-control study in Han Chinese women.

A recent study summarized several published genome-wide association studies (GWASs) of cancer and reported two pleiotropic loci at 6p21.1 and 7p15.3 contributing to multiple cancers including lung cancer, noncardia gastric cancer (NCGC), and esophageal squamous-cell carcinoma (ESCC) in Han Chinese. However, it is not known whether such genetic variants have similar effects on the risk of gynecologic cancers, such as ovarian cancer. Hence, we explored associations between genetic variants in 6p21.1 and 7p15.3 and ovarian cancer risk in Han Chinese women. We performed an independent case-control study by genotyping the two loci (rs2494938 A > G at 6p21.1 and rs2285947 A > G at 7p15.3) in a total of 377 ovarian cancer cases and 1,034 cancer-free controls using TaqMan allelic discrimination assay. We found that rs2285947 at 7p15.3 was significantly associated with risk of ovarian cancer with per allele odds ratio (OR) of 1.33 [95% confidence interval (CI): 1.08-1.64, P=0.008]. However, no significant association was observed between rs2494938 and ovarian cancer risk. Our results showed that rs2285947 at 7p15.3 may also contribute to the development of ovarian cancer in Han Chinese women, further suggesting pleiotropy of 7p15.3 in multiple cancers.

Mechanistic analysis of taxol-induced multidrug resistance in an ovarian cancer cell line.

OBJECTIVES: To establish a taxol-resistant cell line of human ovarian carcinoma (A2780/Taxol) and investigate its biological features. METHODS: The drug-resistant cell line (A2780/Taxol) was established by continuous stepwise selection with increasing concentrations of Taxol. Cell morphology was assessed by microscopy and growth curves were generated with in vitro and in vivo tumor xenograft models. With rhodamine123 (Rh123) assays, cell cycle distribution and the apoptotic rate were analyzed by flow cytometry (FCM). Drug resistance-related and signal associated proteins, including P-gp, MRPs, caveolin-1, PKC-α, Akt, ERK1/2, were detected by Western blotting. RESULTS: A2780/Taxol cells were established with stable resistance to taxol. The drug resistance index (RI) was 430.7. Cross-resistance to other drugs was also shown, but there was no significant change to radioresistance. Compared with parental cells, A2780/Taxol cells were significantly heteromorphous, with a significant delay in population doubling time and reduced uptake of Rh123 (p < 0.01). In vivo, tumor take by A2780 cells was 80%, and tumor volume increased gradually. In contrast, with A2780/Taxol cells in xenograft models there was no tumor development. FCM analysis revealed that A2780/Taxol cells had a higher percentage of G0/G1 and lower S phase, but no changes of G2 phase and the apoptosis rate. Expression of P-gp, MRP1, MRP2, BCRP, LRP, caveolin-1, PKC-α, Phospho-ERK1/2 and Phospho-JNK protein was significantly up-regulated, while Akt and p38 MARK protein expression was not changed in A2780/Taxol cells. CONCLUSION: The A2780/Taxol cell line is an ideal model to investigate the mechanism of muti-drug resistance related to overexpression of drug-resistance associated proteins and activation of the PKC-α/ERK (JNK) signaling pathway.

Clinical application of endoscopic inguinal lymph node resection after lipolysis and liposuction for vulvar cancer.

AIM: To examine lymph nodes obtained after lipolysis and liposuction of subcutaneous fat of the inguinal region of female vulvar cancer patients to explore the feasibility of clinical application. METHODS: The field of operation was on the basis of the range of the conventional resection of inguinal lymph nodes. We injected lipolysis liquid fanwise, started liposuction after 15-20 minutes; then the subcutaneous fatty tissue was sucked out clearly by suction tube. We selected the first puncture holes located on 2-3 cm part below anterior superior spine, the others respectively being located 3cm and 6cm below the first for puncturing into the skin, imbedding a trocar to intorduce CO2 gas and the specular body, and excise the lymph nodes by ultrasonic scalpel. The surgical field chamber was set with negative pressure drainage and was pressured with a soft saline bag after surgery. RESULTS: A lacuna emerged from subcutaneous of the inguinal region after lipolysis and liposuction, with a wide fascia easily exposed at the bottom where lymph nodes could be readily excised. The number of lymph nodes of ten patients excised within the inguinal region on each side was 4-18. The excised average number of lymph nodes was 11 when we had mature technology. CONCLUSION: Most of adipose tissue was removed after lipolysis and liposuction of subcutaneous tissue of inguinal region, so that the included lymph nodes were exposed and easy to excise by endoscope. This surgery avoided the large incision of regular surgery of inguinal region, the results indicating that this approach is feasible and safe for used as an alternative technology.

Modulation of drug resistance in ovarian cancer cells by inhibition of protein kinase C-alpha (PKC-α) with small interference RNA (siRNA) agents.

OBJECTIVE: To determine whether silence of PKC-α expression by small interference RNA (siRNA) might regulate MDR1 expression and reverse chemoresistance of ovarian cancer. METHODS: We measured gene and protein expression of MDR1 and PKC-α in ovarian cancer cells and assessed their correlation with cell drug resistance. We also examined whether blocking PKC-α by RNA interference (RNAi) affected MDR1 expression and reversed drug resistance in drug sensitivity tests. RESULTS: The drug resistance cell lines, OV1228/DDP and OV1228/Taxol, had higher gene and protein expression of MDR1 and PKC-α than their counterpart sensitive cell line, OV1228. SiRNA depressed PKC-α gene protein expression, as well as MDR1 and protein expression and improved the drug sensitivity in OV1228/DDP and OV1228/Taxol cells. CONCLUSION: These results indicated that decreasing PKC-α expression with siRNA might be an effective method to improve drug sensitivity in drug resistant cells with elevated levels of PKC-α and MDR1. A new siRNA-based therapeutic strategy targeting PKC-α gene could be designed to overcome the chemoresistance of ovarian cancer.

Response of IGF and IL-6 to ovarian stimulation in PCOS and normal women.

The objective of the present study was to investigate the response patterns of insulin-like growth factors (IGFs) and interleukin-6 (IL-6) to ovarian stimulation within 24 h in patients with polycystic ovary syndrome (PCOS) in comparison with normally ovulating women. This controlled prospective clinical study involved 60 women who attended an infertility clinic. For the induction of the ovarian stimulation, fifty-two patients with PCOS and eight control cases were injected with human menopause gonadotropin (hMG) and human chorionic gonadotropin (hCG) during the early follicular phase of the natural or induced menstrual cycle. The blood was sampled before (0h) and 6, 12, 18, and 24 h after the stimulation. Serum levels of estradiol (E2), IGF-I, IGF-II and IL-6 were measured by radioimmunoassay. A significant decrease in serum IGF-II at 12 h was observed after a mixture of hMG and hCG was administered in patients with polycystic ovaries (PCO) including the typical PCOS group and the PCO + OA group (accumulated p < 0.05), while normal women presented a slight decrease (accumulated p < 0.1) 18h after the stimulation. Moreover, all the groups had similar serum levels of IL-6 and IGF-I at all time points. An increase in serum E2 occurred coincident with a decrease in IGF-II in all the groups except the ovarian hyperandrogenism patients (HA + OA group). Serum IGF-II levels, which appeared to be negatively correlated with elevated E2, statistically decreased in PCO patients early after hMG and hCG administration when monitored for 24 h, while no such changes were observed in IGF-I and IL-6.

[Microsatellite polymorphism of (tttta) n in the promoter of CYP11a gene in Chinese women with polycystic ovary syndrome].

OBJECTIVE: To investigate the distribution of (tttta) n microsatellite polymorphism in the promoter of CYP11a gene in Chinese women with polycystic ovary syndrome (PCOS) and the relationship between such polymorphism and PCOS. METHODS: Peripheral blood samples were obtained from 201 women with PCOS, aged 26 +/- 4, and 147 women without PCOS, aged 29 +/- 5. Radioimmunoassay was used to examine the levels of testosterone, follicle-stimulating hormone, luteinizing hormone, progesterone, estradiol, and prolactin. Locus-specific prime PCR was used to detect the frequencies of the CYP11a alleles. Body mass index (BMI) was calculated. RESULTS: The average BMI of the women with PCOS was 22 kg/m(2) +/- 4 kg/m(2), and that of the non-PCOS women was 22 kg/m(2) +/- 6 kg/m(2). The six-repeat allele variant genotypic distribution of CYP11a was statistically different between the women with PCOS and those without PCOS [Fisher's exact test (2-tail), P = 0.031]. The frequency of 6//6 genotype in the PCOS patients was 57.7% (116/201), significantly higher than that of the non-PCOS women [44.9% (66/147), chi(2) = 5.588, P = 0.018]. The BMI of the PCOS patients with 4//4 genotype was 19.4 kg/m(2) +/- 1.7 kg/m(2), statistically lower than those of the PCOS patients with 4//6, 6//6, and 6//8 genotypes (23.6 kg/m(2) +/- 3.3 kg/m(2), 22.5 kg/m(2) +/- 3.8 kg/m(2), 22.2 kg/m(2) +/- 4.2 kg/m(2) respectively, P = 0.0037, 0.0027, and 0.059 respectively). The PCOS patients with the allele (tttta) 6 had markedly higher BMI (22.7 kg/m(2) +/- 3.7 kg/m(2)) than those without the allele (tttta) 6 (19.4 kg/m(2) +/- 1.7 kg/m(2), P = 0.0075). No differences were observed in the serum levels of reproductive hormones among the individuals with different genotypic features in the PCOS patients. CONCLUSION: The six-repeat allele is the most common fragment of (tttta) n microsatellite polymorphism in Chinese Han woman. The 6//6 genotype is significantly more frequent and is associated with greater BMI in the women with PCOS. The six-repeat allele variant may play a certain role in the pathogenesis of PCOS.