Jin Song Lu

Identification of the functional role of peroxiredoxin 6 in the progression of breast cancer

IntroductionThe molecular mechanisms involved in breast cancer metastasis still remain unclear to date. In our previous study, differential expression of peroxiredoxin 6 was found between the highly metastatic MDA-MB-435HM cells and their parental counterparts, MDA-MB-435 cells. In this study, we investigated the effects of peroxiredoxin 6 on the proliferation and metastatic potential of human breast cancer cells and their potential mechanism.MethodsExpression of peroxiredoxin 6 in the highly metastatic MDA-MB-231HM cells was investigated by RT-PCR, real-time PCR and western blot. A recombinant expression plasmid of the human peroxiredoxin 6 gene was constructed and transfected into MDA-MB-231 and MDA-MB-435 cells. The effects of peroxiredoxin 6 on the proliferation and invasion of MDA-MB-231 and MDA-MB-435 cells were investigated by the Cell Counting Kit-8 method, colony-formation assay, adhesion assay, flow cytometry and invasion assay in vitro. miRNA was used to downregulate the expression of peroxiredoxin 6. Genes related to the invasion and metastasis of cancer were determined by RT-PCR, real-time PCR and western blot. The tumorigenicity and spontaneously metastatic capability regulated by peroxiredoxin 6 were determined using an orthotopic xenograft tumor model in athymic mice.ResultsOverexpression of peroxiredoxin 6 in MDA-MB-231HM cells compared with their parental counterparts was confirmed. Upregulation of peroxiredoxin 6 enhanced the in vitro proliferation and invasion of breast cancer cells. The enhancement was associated with decreasing levels of tissue inhibitor of matrix metalloproteinase (TIMP)-2 and increasing levels of the urokinase-type plasminogen activator receptor (uPAR), Ets-1 (E26 transformation-specific-1), matrix metalloproteinase (MMP)-9 and RhoC (ras homolog gene family, member C) expression. The results were further demonstrated by RNA interference experiments in vitro. In an in vivo study, we also demonstrated that peroxiredoxin 6-transfected breast cancer cells grew much faster and had more pulmonary metastases than control cells. By contrast, peroxiredoxin 6 knockdown breast cancer cells grew more slowly and had fewer pulmonary metastases. Effects similar to those of peroxiredoxin 6 on the uPAR, Ets-1, MMP-9, RhoC and TIMP-2 expression observed in in vitro studies were found in the in vivo study.ConclusionOverexpression of peroxiredoxin 6 leads to a more invasive phenotype and metastatic potential in human breast cancer, at least in part, through regulation of the levels of uPAR, Ets-1, MMP-9, RhoC and TIMP-2 expression.

ERβ exerts multiple stimulative effects on human breast carcinoma cells

Recent studies of ERs in breast cancer have demonstrated the existence of ERβ in addition to ERα. Some clinical data indicated that ERβ had prognostic value for patients survival, which suggested that ERβ plays a key role in breast cancer development and metastasis. To test this hypothesis, we generated an ERβ high-expression cell line by reintroduced human ERβ cDNA into MDA-MB-435 cells. We demonstrated that ERβ exerted multiple tumor-stimulative effects on human breast carcinoma cells both in vivo and in vitro. In in vitro studies, ERβ was able to increase the proliferation and invasion of MDA-MB-435 cells significantly, while these effects were totally estradiol independent. Also, this stimulation was characterized by downregulation of p21 and upregulation of MMP-9, as well as transcriptional factor Est-1. In in vivo studies, we also demonstrated that ERβ-transfected MDA-MB-435 cells grew much faster and had more pulmonary metastasis than mock or wild-type cells in nude mice. In ERβ-transfected MDA-MB-435 xenografts, ERβ caused significant reduction in p21 protein levels. Similar effects of ERβ on MMP-9 and Ets-1 expression noted in vitro studies were also observed in the in vivo studies. These in vitro and in vivo studies indicated that ERβ exerted multiple stimulative effects on breast cancer development and metastasis.

Development and trends of surgical modalities for breast cancer in China: a review of 16-year data.

BackgroundSurgery is the most important treatment for nonmetastatic breast cancer; however, the utilization of modern surgical techniques in management of breast cancer in mainland China has not been reported.MethodsThe medical records of 5887 consecutive breast cancer patients treated surgically in the past 16 years were reviewed retrospectively; the utilization of different surgical modalities and associated clinical outcomes were analyzed.ResultsMedian age of all patients was 50 (range 16–92). About 1015 patients were staged as 0–I, 3569 stage II, 517 stage III, and 786 cases could not be staged. Extensive radical mastectomy (ERM), radical mastectomy (RM), modified radical mastectomy (MRM), simple mastectomy (SM), and breast-conserving surgery (BCS) were used in 8%, 27.2%, 55.7%, 1.5%, and 6.3% of patients, respectively. In addition, 1.3% of patients received breast reconstruction. The proportion of early-stage breast cancer increased, and the surgery patterns varied. MRM gradually replaced ERM and RM. The prevalence of BCS began to increase from the mid-1990s and currently represents about 12%. The prevalence of reconstruction also increased and now accounts for 5%. Age, pathologic pattern, and TNM staging affected the choice of surgery modalities markedly. Although patients receiving RM/ERM had worse survival than those receiving BCS/MRM, the survival outcomes of these four groups were similar in the early-stage population.ConclusionsMRM remains the most-used surgical modality in operable breast cancer, although the utilization of BCS for early-stage disease has increased rapidly in last decade. Reconstruction following mastectomy as an alternative to BCS is available. Breast-conserving therapy (BCT) and MRM provide similar local controls and long-term survival for breast cancer. Selection of appropriate candidates for a certain surgery requires an assessment of the patient’s age and clinical and pathological characteristics of the tumor.

REV3L 3′UTR 460 T>C polymorphism in microRNA target sites contributes to lung cancer susceptibility

REV3Lp, the catalytic subunit of DNA polymerase zeta, is the major participant in translesion DNA synthesis. Recent evidence suggests that REV3L has an important role in the maintenance of genome stability despite its mutagenic characteristics. Such a function makes it a cancer susceptibility candidate gene. To investigate association between REV3L polymorphisms and lung cancer risk in a Chinese population, we first genotyped 15 common polymorphisms of the REV3L gene and found that three single nucleotide polymorphisms (rs465646, rs459809 and rs1002481) were significantly associated with lung cancer risk. One of the strongest associations observed was for the 3′-terminal untranslated region (3′UTR) 460 T>C polymorphism (rs465646) (adjusted odds ratio (OR)=0.69 for TC/CC; P=0.007, compared with TT). Similar results were obtained in a subsequent replication study (adjusted OR=0.72; P=0.016). Combined data from the two studies of 1072 lung cancer patients and 1064 cancer-free controls generated an even stronger association (adjusted OR=0.71; P=3.04 × 10−4). This 3′UTR 460 T>C variant was predicted to modulate the binding of several micro RNAs. Surface plasmon resonance analysis and luciferase assays showed that the T allele demonstrated a stronger binding affinity for miR-25 and miR-32, resulting in significantly weaker reporter expression levels. Additional experiments revealed that miR-25/32 could downregulate endogenous REV3L. Furthermore, the tumor-suppressing role of REV3L was confirmed by the foci formation assay. These results support our hypothesis that the REV3L rs465646 variant modifies lung cancer susceptibility in Chinese Han population by affecting miRNA-mediated gene regulation.

Dominant-negative E-cadherin inhibits the invasiveness of inflammatory breast cancer cells in vitro

E-cadherin is a transmembrane glycoprotein which mediates epithelial cell-to-cell adhesion function as a tumor suppressor and frequently loss of expression in a wide spectrum of human cancer. However, recent studies demonstrated that E-cadherin was always over-expressed in inflammatory breast cancer (IBC) specimen and cell lines, which is a clinical extreme malignancy of breast cancer. It is hypothesized that the gain and not the loss of the E-cadherin axis contributes to the IBC unique phenotype. To test this assumption, we generated dominant negative mutant E-cadherin high-expression inflammatory breast cancer cells by introduced dominant negative mutant E-cadherin (H-2kd-E-cad) cDNA into human IBC SUM149 cells. Our studies demonstrated that the ability of invasion of SUM149 cells was significantly inhibited by H-2kd-E-cad via down-regulation of MMP-1 and MMP-9 expression. The underlying signal pathway of MAPK phosphorylated Erk 1/2(P44/42) in H-2kd-E-cad-transfected SUM149 cells was significantly down-regulated compared to parental and mock contrast. Our studies provided further functional evidence as the gain of E-cadherin expression dedicated to the IBC malignant phenotype and the blockage of MAPK/Erk activation maybe a promising therapeutic target.

Molecular subtype approximated by quantitative estrogen receptor, progesterone receptor and Her2 can predict the prognosis of breast cancer

AIMS AND BACKGROUND To investigate the clinicopathological characteristics and prognosis of breast cancer subtypes classified by quantitative estrogen receptor (ER), progesterone receptor (PR), and Her2. METHODS AND STUDY DESIGN 923 patients with primary breast cancer having a median age of 53 years who were treated at the Cancer Hospital of Fudan University in Shanghai between January 2002 and June 2004 were retrospectively analyzed. Four molecular subtypes were constructed from the immunohistochemical results of quantitative hormone receptor (HR) and Her2 status. HR+ was defined as ER+ and PR+, HR+/- as ER/PR+ at lower levels or lacking either ER or PR, and HR- as both ER- and PR-. The four subtypes were HR+/Her2-, HR+/-/Her2-, HR-/Her2- (triple-negative), and Her2+. Clinical and pathological parameters, disease-free survival (DFS), and overall survival (OS) measurements were compared between patients with different molecular subtypes. RESULTS The proportions of HR+/Her2-, HR+/-/Her2-, triple-negative, and Her2+ breast cancer were 36.6% (338/923), 22.9% (211/923), 20.6% (190/923), and 19.9% (194/923). The median follow-up was 49.0 months (4-77 months). In 145 cases disease recurrence or death occurred. In multivariate analysis with the HR+/Her2- subtype taken as the reference category, triple-negative and Her2+ subtypes were associated with increased recurrence and death with a hazard ratio (HR) of 2.05 (95% CI 1.31-3.20; P = 0.002) and 1.89 (95% CI 1.20-2.97, P = 0.006) for DFS and 2.84 (95% CI 1.45-5.55; P = 0.002) and 2.95 (95% CI 1.51-5.77, P = 0.002) for OS, respectively; the HR+/-/Her2- subtype was marginally associated with poor prognosis with HR 1.51 (95% CI 0.94-2.43; P = 0.088) and 1.90 (95% CI 0.92-3.94; P = 0.084) for DFS and OS, respectively. CONCLUSIONS Breast cancer subtypes based on quantitative ER, PR, and Her2 may be predictive of prognosis. Patients whose tumors were not HR+/Her2- had a worse outcome in our study.

Breast cancer in Chinese elderly women: Pathological and clinical characteristics and factors influencing treatment patterns

The aims of this study are to describe tumor characteristics and treatment patterns of elder breast cancer patients and to determine the factors influencing local and systemic treatments. This retrospective cohort included 866 patients (>or=60 years) referred for surgery between January 2002 and December 2006. The patients were divided into four groups according to age. Elderly women had larger tumors at diagnosis with more mucinous carcinomas, more estrogen/progesterone-positive, lower Ki-67 labeling indices and less c-erbB2 positive tumors. Comorbidities were more often recorded for older patients. They were more likely to undergo simple mastectomy or breast-conserving surgery, less likely to receive adjuvant chemotherapy and radiotherapy, compared with their younger counterparts. Multinomial and binary logistic regression showed that age was independently associated with local and systemic treatments. Our data suggest that the tumors of elderly patients are biologically more favorable, and elderly women appear to receive less aggressive treatments.

Weekly Paclitaxel/Carboplatin/Trastuzumab Therapy Improves Pathologic Complete Remission in Aggressive HER2-Positive Breast Cancers, Especially in Luminal-B Subtype, Compared With a Once-Every-3-Weeks Schedule

BACKGROUND The efficacy and tolerability of two different schedules of paclitaxel, carboplatin, and trastuzumab (PCarH) for HER2-positive, locally aggressive (stage IIB-IIIC) breast cancers were evaluated in this phase II trial. METHODS Patients were randomly assigned to receive either weekly (12 doses over 16 weeks) or once-every-3-weeks (4 doses over 12 weeks) treatment. The primary endpoint was pathologic complete remission (pCR) in the breast and axilla. To detect an assumed 35% pCR absolute difference between the two schedules, a minimum of 26 assessable patients in each group was required (two-sided α = 0.05, β = 0.2). RESULTS A total of 56 patients were enrolled (weekly group, n = 29; every-3-weeks group, n = 27). In the intent-to-treat analysis, pCR in the breast/axilla were found in 31 patients (55%; 95% confidence interval [CI]: 41%-69%). Compared with the every-3-weeks schedule, the weekly administration achieved higher pCR (41% vs. 69%; p = .03). After adjustment for clinical and pathological factors, the weekly administration was more effective than the every-3-weeks schedule, with hazard ratio of 0.3 (95% CI: 0.1-0.9; p = .03). Interestingly, weekly administration resulted in high pCR rates in both luminal-B (HER2-positive) and ERBB2+ tumors (67% vs. 71%; p = .78), whereas luminal-B (HER2-positive) tumors benefited less from the every-3-weeks schedule compared with the ERBB2+ tumors (21% vs. 62%, p = .03). These results remain after multivariate adjustment, showing weekly administration was more effective in the luminal-B (HER2-positive) subgroup (p = .02) but not in the ERBB2+ subgroup (p = .50). CONCLUSION A more frequent administration might improve the possibility of eradicating invasive cancer in the breast and axilla, especially in the luminal-B (HER2-positive) subtype. Further studies to validate our findings are warranted.

Fiberoptic ductoscopy-guided intraductal biopsy improve the diagnosis of nipple discharge.

Abstract:  Fiberoptic ductoscopy (FDS)‐guided intraductal biopsy is a minimally invasive technique developed to obtain pathologic diagnoses for patients with spontaneous nipple discharge. We performed biopsies of 53 intraductal lesions from March 2006 to April 2007 followed by surgical microdochectomy. FDS‐guided intraductal biopsy was shown to be a minimally invasive, safe, and convenient technique with a high ability (90.6%) to get adequate samples. Twenty‐seven solitary papillomas, 12 multiple intraductal papilloma, five ductal hyperplasia, three ductal carcinoma in situ, and one invasive ductal carcinoma were diagnosed. Compared with conventional microdochectomy, FDS‐guided intraductal biopsy can significantly increase the detection rate of solitary papilloma (40.7% versus 92.6%, p < 0.05). It should be a routine procedure after intraductal lesion found by screening FDS. Since it would underestimate all multiple intraductal papilloma and some (50%) cancer, microdochectomy is inevitable if biopsies show atypical ductal hyperplasia.

Models for predicting BRCA1 and BRCA2 mutations in Han Chinese familial breast and/or ovarian cancer patients

Purpose Our aim was to find an appropriate method to estimate the likelihood that a family history of cancer was a result of a mutation in the BRCA1 or BRCA2 genes. We also compared the performance of the established method with three different methods (Couch, Sh-E and BRCApro) to identify an alternative strategy for genetic council targeted to the specified population. Patients and methods The family history as well as individual information of two hundred unrelated probands who had completed BRCA1 and BRCA2 mutation screening was analyzed to assess the likelihood of a pathogenic mutation. A model was developed by empirical method. The performance of this model was validated in a separate patient cohort compared with BRCApro. Results Several factors were associated with mutations in univariate analysis and a logistic model was devised to estimate the probability for a proband of harboring a mutation in BRCA1 and/or BRCA2. Using a greater than 10% probability threshold, the highest accuracy was achieved by the established model when compared to other three models, presenting the highest sensitivity, PPV, NPV and area under ROC curve. The empirical model showed a better ROC curve compared to BRCApro in the verification cohort. Conclusion A probability model targeted to Han Chinese population should be a useful tool in the genetic counseling for the specified ethnic. Its ability to predict BRCA2 mutation carriers needs to be improved.