Wu Y

Reversal of Multidrug Resistance by Gefitinib Via RAF1/ERK Pathway in Pancreatic Cancer Cell Line

Pancreatic cancer is a devastating malignancy, characterized by intrinsic or acquired resistance to conventional chemotherapies. Recent evidences suggest an involvement of tyrosine kinase pathway in the regulation of multidrug resistance (MDR) protein gene expression. The aim of this study was to test whether gefitinib, an epidermal growth factor receptor tyrosine kinase inhibitor could regulate the MDR protein gene expression and sensitize the resistant cancer cells to chemotherapy. The gene expression of MDR proteins (MRP1, MRP2, MRP3, and PGP) were evaluated by quantitative RT‐PCR, and expression levels of various tyrosine kinases were investigated by quantitative RT‐PCR and Western Blot in pancreatic cancer cell line. MTT assay was used for evaluating the effect of chemotherapeutic agents. Chemotherapeutics induced drug resistance by regulating the gene expression of MDR proteins (MRP1, MRP2, and MRP3), and increased the gene expression of RAF1/ERK and the phosphorylation of ERK in pancreatic cancer Bxpc‐3 cells. Gefitinib caused an inhibition of p‐ERK tyrosine kinase activation in a dose‐dependent manner, and reversed gemcitabine‐induced RAF1/ERK gene expression and p‐ERK activation. In addition, a reversal of MDR proteins gene expression was achieved by gefitinib, which sensitized resistant cells to gemcitabine. This study demonstrated that MDR of Bxpc‐3 cell is involved in the RAF1/ERK tyrosine kinase pathway. Gefitinib reverses the MDR protein gene expression and restores sensitivity of resistant cells to gemcitabine via RAF1/ERK signaling pathway. Combination of gefitinib with conventional chemotherapeutic agents may offer a new approach for the treatment of patients with pancreatic cancer. Anat Rec, 2012.

Associations between body mass index and molecular subtypes as well as other clinical characteristics of breast cancer in Chinese women.

Background: Several studies have shown a positive association between body mass index (BMI) and the development of hormone receptor-positive breast cancer in postmenopausal women; however, the associations between BMI groups and molecular subtypes have yet to be well defined in premenopausal breast cancer patients. Methods: A total of 2465 female breast cancer patients diagnosed at our institution were recruited for this study. Clinicopathologic information (including age, body height and weight, as well as tumor subtypes and stages) was collected; analyses of these characteristics and the associations between them were performed. Results: A total of 1951 cases were included in the study. The mean age was 47.3 years, the majority of patients were of normal weight, premenopausal, had stage 2 cancer, and did not present with positive nodes. The prevalence of the luminal A, luminal B, human epidermal growth factor receptor 2+, and triple-negative subtypes were 57.8%, 11.6%, 6.1%, and 24.5%, respectively. There were significant differences in the clinicopathologic features among BMI groups in premenopausal patients. The case-only odds ratio (OR) analysis revealed that normal weight patients tended to have luminal B cancer (OR = 1.4, P = 0.206), and overweight and obese patients tended to have triple-negative cancer in premenopausal patients (OR = 2.8, OR = 3.7, respectively; P < 0.001). Conclusion: In Chinese women, breast cancer came with these characteristics: young mean age (premenopause), luminal A subtype, and the majority of them were within a normal weight range. In premenopausal patients, underweight patients tended to have luminal A, lower human epidermal growth factor receptor 2+ expression, stage 1 and no positive node cancer. However, overweight and obese patients tended to have a triple-negative, stage 3, and lymph node metastatic cancer.

Haplotype analysis of eight genes of the monoubiquitinated FANCD2–DNA damage–repair pathway in breast cancer patients

BACKGROUND Ten genes are associated with increased susceptibility to inherited breast cancer have also been associated with population breast cancer risk, and all are involved directly or indirectly in the monoubiquitinated FANCD2-DNA damage repair pathway. We analyzed 13 haplotype blocks in eight of these genes to estimate the breast cancer risk conferred by individual haplotypes. METHODS Haplotype blocks were constructed with 48 tag single-nucleotide polymorphisms (tSNPs) identified in eight breast cancer susceptibility genes, TP53, PTEN, CHEK2, ATM, NBS1, RAD50, BRIP1, and PALB2. Genotyping was performed by SNPscan on 734 female patients and 672 female age-matched controls. RESULTS Forty-five tSNPs were successfully genotyped by SNPscan, and call rates for each tSNP were above 98.9%. Thirteen haplotype blocks of eight genes were constructed with 41 successfully genotyped tSNPs. We found that seven haplotypes from four haplotype blocks located within three genes (NBS1, PTEN, and BRIP1) were significantly associated with breast cancer risk. Among these, four haplotypes (ATC in block 1 of NBS1, GCCCC and GCCCT in block 2 of NBS1, and GCT in block 2 of BRIP1) were correlated with breast cancer risk in sporadic cases (OR (95% CI) 1.350(1.124-1.623), 0.752(0.584-0.969), 0.803(0.649-0.993), and 0.776(0.604-0.997), respectively), and only one haplotype (GGCCT in block 2 of NBS1) was significantly associated with breast cancer risk in familial and early-onset cases (OR(95% CI) 1.902(1.134-3.191)). CONCLUSIONS Four haplotypes within two genes (NBS1 and BRIP1) involved in the monoubiquitinated FANCD2-DNA damage-repair pathway are significantly associated with increased sporadic breast cancer risk, while one haplotype within NBS1 is correlated with an increased risk of familial or early-onset breast cancer, indicating that specific haplotypes may be distinct predictors of breast cancer.

[PTEN and NBS1 gene mutations in familial breast cancer and early-onset breast cancer from Hunan Province in China].

OBJECTIVE To investigate the profile and potential significance of PTEN and NBS1 mutations among patients with familial or at early onset breast cancer in Hunan province.
 METHODS A total of 131 breast cancer patients with familial history or suffered from breast cancer at the age of less than 35 years old were included in this study. A comprehensive phosphatase and tensin homolog (PTEN) and nibrin (NBS1) mutation analysis was performed through denaturing high performance liquid chromatography (DHPLC) and subsequent DNA direct sequencing.
 RESULTS Among 131 patients, a reported mutation IVS4+109insTCTTA in PTEN gene were identified in two patients. The mutation frequency of IVS4+109insTCTTA was 1.15%. Two mutations in PTEN gene, 225 A>C (Thr 160 Pro) and IVS5+13T>C, was firstly discovered. Another reported missense mutation was rs121909229 G>A (Arg 130 Gln). Three mutations were detected in NBS1 gene, of which IVS6+43A>G and IVS6+127A>G were firstly discovered and another reported synonymous mutations was rs1805794 G>C (Glu 185 Gln).
 CONCLUSION The novel mutations in PTEN and NBS1 might be specific to the familial and early-onset breast cancer of Chinese Hunan population.

[HSV-1 based vector mediated IL-1Rα gene for knee osteoarthritis in rabbits].

OBJECTIVE To investigate the effect and mechanism of herpes simplex virus type 1 (HSV-1) based vector mediated interlukin-1 receptor antagonist (IL-1Rα) gene for knee osteoarthritis in rabbits. METHODS HSV-1 vectors containing IL-1Rα genes were constructed and injected into the joint space of the osteoarthritis knee in rabbits for 4 weeks. The rabbits were sacrificed, and the knees were lavaged, dissected and the effect of transgene expression was analyzed. Levels of IL-1Rα and IL-1 expression in the recovered lavage fluids were measured with a cytokine ELISA kit. Cartilage from the lesion areas of medial femoral condyle and synovium were observed with hematoxylin and eosin (cartilage and synovium) and toluidine blue (cartilage). The blank control group was injected pHSV-LacZ vector into rabbit knees. RESULTS Intra-articular delivery of pHSV-IL-1Rα-LacZ resulted in a significant inhibition of IL-1 level and cartilage degradation compared with those in the blank control group (P<0.05). CONCLUSION pHSV-LacZ is an ideal vector to mediate intra-articular gene delivery in the rabbit model of osteoarthritis. Continuous intra-articular expression of IL-1Rα can treat knee osteoarthritis by inhibiting IL-1.

Expression and distribution of transforming growth factor β3 in the mouse tooth germ during development after advanced bell stage

OBJECTIVE To observe the expression and distribution of transforming growth factor β3 (TGF-β3) in the mouse tooth germ after advanced bell stage, and to discuss the role of TGF-β3 during the development of tooth germs. METHODS BALB/Cs mouse tooth germs at 4, 11, and 18 days postnatal (4dpn,11dpn,and 18dpn) were collected and processed for routine fixation, decalcification, embedding, and slicing. The expression of TGF-β3 was detected by immunohistochemisty. RESULTS As to 4dpn tooth germ: Positive expression of TGF-β3 was found in enameloblasts, odontoblasts, ambitus of dental pupilla, with weak positive expression in the intermedial of dental papilla. As to 11dpn tooth germ: Positive expression was seen in enameloblasts, with negative expression in odontoblasts and dental papilla. As to 18dpn tooth, positive expression of TGF-β3 was showed in the vessel wall and its surrounding, with negative expression in other areas. CONCLUSION The distribution of TGF-β3 expression showed a time-space characteristic during the mouse tooth germ development after advanced bell stage, which may exert a regulatory effect on tooth development and this effect is gradually getting weak with the development of tooth germs.

Therapeutic effect of the combination of traditional Chinese medicine and western medicine on patients with oral submucous fibrosis

OBJECTIVE To observe the therapeutic effect of salvia miltiorrhiza and prednisolone on patients with oral submucous fibrosis (OSF). METHODS A total of 60 medium-term OSF patients and 60 advanced stage OSF patients were randomly divided into the first group (treated with both salvia miltiorrhiza and prednisolone) and the second group (treated with prednisolone alone). The clinical effect was compared between each group after 3-month treatment. RESULTS Difference was found in the lesion area of the medium-term cases and the advanced stage cases of the first group before the treatment [(10.37+/-3.40) cm2, (19.60+/-3.27) cm2] and after the treatment [(5.90+/-4.10) cm2, (16.33+/-4.02) cm2] (P<0.05). Significant difference was found in the mouth opening before the treatment [(3.41+/-0.77) cm, (1.98+/-0.39) cm] and after the treatment [(3.87+/-0.67) cm, (2.26+/-0.46) cm] (P<0.05) in the first group. There was significant difference in the lesion area and mouth opening of the medium-term cases of the second group before the treatment [(10.87+/-3.18) cm2, (3.57+/-0.75) cm] and after the treatment [(6.70+/-3.75) cm2, (3.97+/-0.69) cm] (P<0.05). No difference in the lesion area and mouth opening of the advanced stage cases of the second group was found (P>0.05). There was difference in the therapeutic efficacy between the first group (70%) and the second group (16.67%) of the advanced stage cases (P<0.05), but not in the clinical effect between the 2 groups of the medium-term cases (P>0.05). The side effect of prednisolone could be reduced while used together with salvia miltiorrhiza. CONCLUSION There is obvious advantage in treating OSF by the combination of salvia miltiorrhiza and prednisolone.