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Background Endostar (rh-endostatin) is a new recombinant human endostatin, which could inhibit cell proliferation, angiogenesis, and tumor growth. Objective To explore anti-angiogenesis short-term efficacy combined with neoadjuvant chemotherapy for stage IIIA (N2) non-small cell lung cancer (NSCLC), and identify the potential predictive factors. Methods We pathologically examined 26 patients diagnosed with stage IIIA (N2) NSCLC who received NP chemotherapy alone or combined with Endostar, respectively. Results Our results indicated that total clinical benefit rate (CBR) 87.5% and 64% (p= 0.76), respectively. The clinical benefit (CB) patients in the treatment group showed significant changes in endothelial progenitor cells (EPC), vascular endothelial growth factor (VEGF), blood flow (BF), permeability surface (PMS), and microvascular density (MVD) before and after treatment. Compared with CB patients in the control group, changes in EPC and MVD (only) before and after treatment were significant. The variation of EPC, PMS, and MVD before and after treatment in the treatment group showed positive correlation with tumor regression rate (TRR) and the variation of MVD, whereas those of EPC and PMS demonstrated positive correlations with variation of MVD before and after treatment. Conclusion Our findings suggested that PMS and EPC may be used as a predictive factor for the short-term efficacy of the combined therapy in NSCLC.

Lung cancer stem cells (LCSCs) are considered as the cellular origins of metastasis and relapse of lung cancer. However, routine two-dimensional culture system (2D-culture) hardly mimics the growth and functions of LCSCs in vivo and therefore significantly decreases the stemness activity of LCSCs. In this study, we constructed a special BME-based three-dimensional culture system (3D-culture) to amplify LCSCs in human lung adenocarcinoma cell line A549 cells and found 3D-culture promoted the enrichment and amplification of LCSCs in A549 cells displaying higher proliferation potential and invasion activity, but lower apoptosis. The expression and secretion levels of FGF1 and IGF1 were dramatically elevated in 3D-culture compared to 2D-culture. After growing in FGF1 and IGF1-conditioned 3D-culture, the proportion of LCSCs with specific stemness phenotypes in A549 cells significantly increased compared to that in conventional 3D suspension culture system. Further results indicated that FGF1 and IGF1 promoted the amplification and cancer stemness of LCSCs dependent on MAPK signaling pathway. Our data firstly established a growth factors-conditioned 3D-culture for LCSCs and demonstrated the effects of FGF1 and IGF1 in promoting the enrichment and amplification of LCSCs which might provide a feasible cell model in vitro for both mechanism study and translational research on lung cancer.

Although the upregulated expression of Anxa2 has been implicated in carcinogenesis, cancer progression, and poor prognosis of cancer patients, the detailed molecular mechanisms involved in these processes remain unclear. In this study, we investigated the effect of Anxa2 downregulation with small interference RNA on breast cancer proliferation. To explore molecular mechanisms underlying Anxa2-mediated cancer cell proliferation. We analyzed cell cycle distribution and signaling pathways using semi-quantitative real-time PCR and Western blotting. Anxa2 depletion in breast cancer cells significantly inhibited cell proliferation by decelerating cell cycle progression. The retarded G1-to-S phase transition in Anxa2-silenced cells was attributed to the decreased levels of cyclin D1, which is a crucial promoting factor for cell proliferation because it regulates G1-to-S phase transition during cell cycle progression. We provided evidence that Anxa2 regulates epidermal growth factor-induced phosphorylation of STAT3. The reduced expression of phosphorylated STAT3 is the main factor responsible for decreased cyclin D1 levels in Anxa2-silenced breast cancer cells. Our results revealed the direct relationship between Anxa2 and activation of STAT3, a key transcription factor that plays a pivotal role in regulating breast cancer proliferation and survival. This study provides novel insights into the functions of Anxa2 as a critical molecule in cellular signal transduction and significantly improves our understanding of the mechanism through which Anxa2 regulates cell cycle and cancer cell proliferation.

The centrosome plays an essential role in chromosomal segregation during cell division. Centrosome dysfunction might lead to aneuploidy and chromosomal instability. Invasive breast tumors with centrosome amplification often show aneuploidy. Flow cytometry (FCM) was used to examine the aneuploidy rate in 30 cases of each of the following seven tissue types: normal breast tissue, usual ductal hyperplasia, atypical ductal hyperplasia, low-grade ductal carcinoma in situ, high-grade ductal carcinoma in situ, low-grade invasive ductal carcinoma, and high-grade invasive ductal carcinoma. Centrosomal α, γ-tubulin expression was examined by FCM immunofluorescence and compared between diploid and aneuploid cells. The aneuploidy rate was 0, 6.7%, 26.7%, 30.0%, 46.7%, 56.7%, and 86.7%, respectively, in the seven tissue types. The percentage of cells expressing α- and γ-tubulins was significantly different between the seven groups, and the positive rate of α- and γ-tubulin expression in ADH, DCIS and IDC was higher than that in NBT and UDH. The percentage of cells expressing α- and γ-tubulins in the diploid state was significantly lower than that in the aneuploid state. Expression of centrosomal α- and γ-tubulins seems to be associated with DNA ploidy in breast premalignant lesions and carcinoma during the progression of breast cancer.

The current criteria for evaluating antiangiogenic efficacy is insufficient as tumor shrinkage occurs after blood perfusion decreases. Tumor blood volume (BV) in computed tomography perfusion imaging and circulating endothelial cells (CEC) might predict the status of angiogenesis. The present study aimed to validate their representation as feasible predictors in non-small-cell lung carcinoma (NSCLC). A total of 74 patients was categorized randomly into two arms undergoing regimens of vinorelbine and cisplatin (Navelbine and platinum [NP]) with rh-endostatin or single NP. The response rate, perfusion imaging indexes and activated CEC (aCEC) during treatment were recorded. Progression-free survival (PFS) was determined through follow up. Correlations among the above indicators, response and PFS were analyzed: aCEC increased significantly in cases of progressive disease after single NP chemotherapy (P = 0.024). Tumor BV decreased significantly in cases with a clinical benefit in the combined arm (P = 0.026), whereas inverse correlations existed between ∆aCEC (post-therapeutic value minus the pre-therapeutic value) and PFS (P = 0.005) and between ∆BV and PFS (P = 0.044); a positive correlation existed between ∆aCEC and ∆BV. Therefore, both aCEC and tumor BV can serve as predictors, and detection of both indicators can help evaluate the chemo-antiangiogenic efficacy in NSCLC more accurately.

[Gd@C82(OH)22]n, a fullerene-based nanoparticle, exhibits potent anti-tumor effects in mouse tumor-bearing models without detectable toxicity and the pathological studies revealed a massive infiltration of leukocytes in the residual tumors of [Gd@C82(OH)22]n-treated mice. We report here that [Gd@C82(OH)22]n promotes macrophages secreting pro-inflammatory cytokines IL-6 and TNF-alpha, enhances the expression of MHC-II and costimulatory molecules such as CD40 and CD54, increases endocytosis and cell adhesion. Furthermore, [Gd@C82(OH)22]n-treated macrophages became functionally activated as illustrated by their capacity to activate allogeneic T cells. Taken together, our results indicate that [Gd@C82(OH)22]n nanoparticle is a potent activator of macrophages, which may in part account for its potent anti-tumor effect.

Objective To screen specific polypeptide target binding to breast cancer xenografts in vivo from a phage-displayed peptide library in order to provide peptide sequences for breast cancer tumor-targeting diagnosis and therapy.

The cellular Fas-associated death domain-like interleukin-1beta-converting enzyme inhibitory protein-long form (c-FLIP(L)) is a key regulator of Fas signaling, although owing a dominant-negative homologue of caspase-8, the role of c-FLIP(L) remains controversial. In the present study, two pairs of small interfering RNA (siRNA) directed against c-FLIP(L) were used to assess the effect of c-FLIP(L) on Fas-mediated apoptosis of colon carcinoma in vitro. HT-29 cell line was selected for overexpression of c-FLIP(L) and Fas with RT-PCR and flow cytometry analyses. After electroporation, the mRNA level of c-FLIP(L) was significantly decreased (control siRNA versus c-FLIP(L) siRNA, 77.97+/-5.61% versus 26.22+/-3.79%) and the maximum interfering efficiency was around 66.49% using semi-quantitative RT-PCR analysis. Knockdown of c-FLIP(L) with the specific siRNA sensitized colon carcinoma cells to Fas-mediated apoptosis (control siRNA versus c-FLIP(L) siRNA, 5.68+/-2.11% versus 29.50+/-2.27%) using DNA content analysis and Annexin V-FITC analysis. In conclusion, our study indicated that c-FLIP(L) might be a suppressor of Fas-mediated apoptosis in Fas antigen expressing colon carcinoma and therefore a potential target for novel anticancer therapies.

To investigate the changes and values of the expression of α-tubulin and γ-tubulin in atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) of the breast. The relationship between centrosome abnormalities and breast tumor development was further discussed. There were three groups including ADH, DCIS and IDC with 30 cases in each group. They were analyzed by immuno-fluorescence quantity analysis. The expression levels of α-tubulin and γ-tubulin protein in these tissues were detected by flow cytometry immuno-fluorescence analysis and compared with the results from normal tissues. Immunohistochemistry was also performed in this research. The results showed significant differences of the average of the positive (FITC labeled) cells (P=0.000) among the four groups. The level of the IDC group was the highest, while normal breast tissue showed the lowest level. The results suggested that the expression levels of α-tubulin and γ-tubulin both increased as the grade of cellular proliferation and differentiation increased. The expressions showed significant differences among all the groups, except between the ADH and DCIS. There were no significant differences between α-tubulin and γ-tubulin expression in each group (P

OBJECTIVE To investigate the efficiency of gene silencing by CXCR4-siRNAs (small interfering RNA), and to examine the invasive ability and the expression of other metastatic associated genes in siRNA-treated breast cancer cells. METHODS Three siRNAs were designed and cloned into the pSilenc™ 3.1-H1 neo vector. The reconstructed plasmids were purified and trans-fected into the T47D breast cancer cell line, which highly expressed CXCR4. The amount of CXCR4 expression in the transfected cells was measured by flow cytometry and Real-time PCR. Cell invasive ability was evaluated us -ing 24-well Matrigel invasion chambers. In addition, the expression of other metastatic-associated genes, such as E-cad, IGFBP-5, FN and MMP-2, was assessed by Real-time PCR. RESULTS The suppression rates of CXCR4 mRNA expression reached 95.7%, 85.9% and 98.3%compared with control-siRNA cells in the 3 CXCR4-siRNA T47D cells respectively. FCM assays for CXCR4 protein expression showed a similar inhibitory effect. The invasion indexes of these CXCR4-siRNA cells were 0.037, 0.290 and 0.188respectively compared with control-siRNA cells. After treatment of the cells with CXCR4-siRNA, the expression of E-cad showed an upward tendency and that of IGFBP-5 had a downward trend, while alteration in expression of FN and MMP2 varied without a con -sistant effect. CONCLUSION CXCR4 plays an important role in modulating migra-tion of human breast cancer cells. Small interfering RNA can significantly silence the CXCR4 gene in the human T47D breast cancer cell line. The results of this study strengthen the need for further research on novel gene therapy against breast cancer metastasis.

In order to investigate the role of mitochondrial DNA (mtDNA) in human breast cancer cell proliferation and apoptosis, a mtDNA-deficient cell line, T47D rho(0), was generated following a long-term exposure to ethidium bromide (EtBr). T47D rho(0) cells showed a marked decrease in mitochondrial membrane potential (DeltaPsi(m)). However, the apoptosis rate of T47D rho(0) cells was the same as that of their parental cells, suggesting that the change in DeltaPsi(m) was insufficient to induce cell death. Electromicroscopy revealed a profound alteration of mitochondrial morphology, which was consistent with the loss of mtDNA and the decrease in DeltaPsi(m). Disruption of mtDNA resulted in a slower proliferation rate in tissue culture and a reduction in anchorage-independent growth. An in vivo assay revealed a severe impairment of tumorigenicity in T47D rho(0) cells, indicating the biological relevance of in vitro studies. Taken together, our results suggest that the integrity of mtDNA plays a critical role in human breast cancer cell proliferation and tumorigenesis.

Objective To study the expression levels of Twist and epithelialmesenchymal transitions in multidrug-resistant MCF-7/ADR breast cancer cells, and to study the relationship between multidrug resistance (MDR) and metastatic potential of the cells.

OBJECTIVE Hepatocellular carcinoma (HCC) is a hypervascular tumor for which angiogenesis plays an important role in its progression. The aim of this study was to investigate the expression of TWIST and VEGF and determine their roles in angiogenesis of HCC. METHODS Expression Twist and VEGF mRNA was determined by realtime RT-PCR in 30 pairs of hepatocellular carcinoma and matched noncancerous tissues. Immunohistochemistry was carried out to analyze the protein expression of Twist and VEGF in 40 hepatocellular carcinoma cases. Staining of endothelial cells for CD34 was used to evaluate the microvessel density (MVD). RESULTS We found that the HCC specimens showing positive Twist expression in tumor cells had a higher microvessel density than those without Twist expression. Furthermore, we found that overexpression of the Twist protein positively correlated with up-regulation of VEGF in the HCC tissues (r=0.479, P=0.002). CONCLUSION Our results demonstrate that Twist may play an important role in the angiogenesis of HCC and a high-level of Twist expression may be related to the malignant potential of tumor cells.

OBJECTIVE To investigate the effect of proteasome inhibition on the sensitivity of carcinoma cells to TRAIL-inducing apoptosis, and to study the mechanism of the response.

Objective The aim of this research was to clone and express the antigen of the previously prepared monoclonal antibody named M4G3.

To investigate the expression of apoptotic regulator c-FLIP(L) in invasive breast carcinoma tissues, and to evaluate its correlation with molecular subtyping and clinical prognosis.Immunohistochemistry using EnVision staining for c-FLIP(L) was performed in 264 cases of invasive breast carcinomas and matched adjacent normal breast tissue samples from January 1996 to December 1999. ER, PR, HER2, Ki-67, CK5/6 and EGFR were evaluated by immunohistochemistry in order to classify the tumors into five molecular subtypes and the difference of c-FLIP(L) expression in these molecular subtypes was also analyzed. The influence of c-FLIP(L) expression on prognosis was evaluated by Kaplan-Meier curves and multi-factor Cox proportional risk model.High expression of c-FLIP(L) was observed in 84.5% (223/264) of cases of invasive breast carcinomas which were significantly higher than the 45.1% (119/264) of cases in adjacent normal epithelium of breast (χ² = 89.78, P = 0.000). The expression of c-FLIP(L) in luminal B (HER2 positive) and basal-like breast cancers was 78.1% (25/32) and 46.2% (18/39), respectively, with significant difference (P0.05). Moreover, the expression of c-FLIP(L) in luminal B (HER2 positive) was higher than in luminal A cancers (P0.05), and the expression of c-FLIP(L) in HER2 positive cancers was higher than in basal-like cancers (P0.01). C-FLIP(L) showed deep yellow staining in node positive breast cancer with a high-expression rate of 93.1% (134/144); whereas the expression was sporadic and light yellow in node negative breast cancer with a lower high-expressed rate of 72.5% (87/120, P0.01). C-FLIP(L) expression had significant influence on disease-free survival time, with c-FLIP(L)-positive patients showing poor prognosis (P0.01). Multi-factor Cox proportional risk model analysis showed that expression of c-FLIP(L), lymph nodes status and molecular subtypes were independent prognostic factors for invasive breast carcinomas (P0.05).C-FLIP(L) is highly expressed in invasive breast carcinomas, and its expression level is closely related to the molecular subtypes and clinical prognosis of breast cancer patients. Thus, c-FLIP(L) could be used as an important tumor marker for personalized cancer therapy and prognostic prediction.

Breast cancers with HER2 amplification have a poorer prognosis than the luminal phenotypes. TRAIL activates apoptosis upon binding its receptors in some but not all breast cancer cell lines. Herein, we investigated the expression pattern of c-FLIP(L) in a cohort of 251 invasive breast cancer tissues and explored its potential role in TRAIL resistance. C-FLIP(L) was relatively high-expressed in HER2-positive breast cancer in comparison with other molecular subtypes, co-expressed with TRAIL death receptors, and inversely correlated with the apoptosis index. Downregulation of c-FLIP(L) sensitized SKBR3 cells to TRAIL-induced apoptosis in a concentration- and time-dependent manner and enhanced the activities and cleavages of caspase-8 and caspase-3, without altering the surface expression of death receptors. Together, our results indicate that c-FLIP(L) promotes TRAIL resistance and inhibits caspase-3 and caspase-8 activation in HER2-positive breast cancer.

Aim To investigate the role of neurotensin (NTS) in hepatocellular carcinoma (HCC) sub- grouping and the clinical and pathological significance of activation of NTS/IL-8 pathway in HCC. Methods The genome-wide gene expression profiling were conducted in 10 pairs of cancer tissues and corresponding normal adjacent tissues samples using Affymetrix GeneChip® Human Genome U133 Plus 2.0 microarray to screen differentially expressing genes and enrich dysfunctional activated pathways among different HCC subgroups. The levels of NTS protein and multiple inflammation and epithelial mesenchymal transition (EMT) related proteins, including IL-8, VEGF, MMP9, CD68, E-Cadherin, β-Catenin and Vimentin were examined in 64 cases of paraffin-embedded HCC samples using immunohistochemistry (IHC) staining method. The clinical outcome and overall survival (OS) were compared. Results A subgroup of HCC characterized by up-regulated NTS expression was accompanied by up-regulated inflammatory responses and EMT. The direct interaction between NTS and IL-8 was identified by pathway enrichment analysis. Significantly increased IL-8 protein was confirmed in 90.91% of NTS(+) HCC samples and significantly positively correlated to the levels of NTS protein in cancer tissues (P = 0.036), which implied activation of NTS/IL-8 pathway in HCC. The levels of VEGF and MMP9 correlated with co-expression of NTS and IL-8. Increased infiltration of CD68(+) macrophages and more cancer cells displaying EMT features were found in NTS(+)IL-8(+) samples. The co-expression of NTS and IL-8 in cancer significantly correlated with the clinical outcomes, as the mortality rate of NTS(+)IL-8(+) HCC patients is 2.5-fold higher than the others after the surgery (P = 0.022). Accordingly, the OS of NTS(+)IL-8(+) HCC patients significantly decreased who are under a higher hazard of death at an expected hazard ratio (HR) of 3.457. Conclusion Dysfunctional activation of the NTS/IL-8 pathway was detected in HCC which is associated with increased inflammatory response in microenvironment, enhanced EMT in cancer, and worse prognosis in HCC patients.

Endostatin can normalize the tumor vasculature to some extent. However, exact length of its time window and corresponding markers for tumor vascular normalization are needed to be explored. The A549 lung adenocarcinoma xenograft murine model was treated with recombinant human endostatin (rh-endostatin) for 14 days. Cisplatin was combined in different schedules. The effects of rh-endostatin on circulating endothelial cells (CECs) by flow cytometry, tumor vasculature and angiogenesis-related factors by confocal microscope and immunohistochemistry, and anti-tumor efficacy of cytotoxic drugs were observed. The activated CECs (aCECs) were increased on day 7 and decreased on day 10, and apoptotic CECs were increased on day 10. Tumor vasculature was transiently normalized with increased collagen coverage, decreased vessel permeability, intratumoral hypoxia, and microvascular density from day 7 to 10 after rh-endostatin administration. Extracellular matrix metalloproteinase inducer, vascular endothelial growth factor, matrix metalloproteinase (MMP)-2, and MMP-9 were transiently decreased by rh-endostatin from day 4 to 10, whereas the opposite effects were observed with tissue inhibitors of matrix metalloproteinase (TIMP)-1 and TIMP-2. The maximal anti-tumor effects of cisplatin were observed on administration from day 5 to 9 after rh-endostatin initial administration. Rh-endostatin could transiently normalize tumor vasculature, probably via regulation of both pro- and anti-angiogenesis factors. The synergistic efficacy of anti-angiogenesis and chemotherapy was found during “the normalization window”. CEC could be a feasible blood biomarker for defining “vascular normalization window” and providing the evidence to make an optimizing combination therapeutic schedule in human tumor.

[Gd@C82(OH)22]n, a fullerene-based nanoparticle, exhibits potent anti-tumor effects in mouse tumor-bearing models without detectable toxicity and the pathological studies revealed a massive infiltration of leukocytes in the residual tumors of [Gd@C82(OH)22]n-treated mice. We report here that [Gd@C82(OH)22]n promotes macrophages secreting pro-inflammatory cytokines IL-6 and TNF-alpha, enhances the expression of MHC-II and costimulatory molecules such as CD40 and CD54, increases endocytosis and cell adhesion. Furthermore, [Gd@C82(OH)22]n-treated macrophages became functionally activated as illustrated by their capacity to activate allogeneic T cells. Taken together, our results indicate that [Gd@C82(OH)22]n nanoparticle is a potent activator of macrophages, which may in part account for its potent anti-tumor effect.

Multidrug resistance (MDR) is the major cause of failure in cancer chemotherapy. Recent reports even suggest that MDR is associated with elevated invasion and metastasis of tumor cells. In the current study, we used a proteomic approach to identify genes that play an important role in MDR induced cell migration. 2D-PAGE and MALDI-TOF/MS-based proteomics approach were used to separate and identify differentially expressed proteins between MCF-7 and MCF-7/ADR, a p-glycoprotein-overexpressing adriamycin-resistance breast cancer cell line. Annexin a2 (Anxa2) was identified as highly expressed in MCF-7/ADR cells, but not in MCF-7 cells. Small interference RNA-mediated gene suppression demonstrated that Anxa2 was required for enhanced cell proliferation and invasion of the MCF-7/ADR cells. Down-regulation of Anxa2 alone was not sufficient to revert the cell sensitivity to adriamycin, suggesting that Anxa2 was not required for MDR phenotype. Taken together, our results showed that expression of Anxa2 is enhanced when cancer cells, MCF-7, acquired drug resistance and it plays an essential role in MDR-induced tumor invasion.

The mutation and reduction of mitochondrial DNA (mtDNA) have been extensively detected in human cancers. The effects of mitochondrial dysfunction are particularly important in breast cancer, because estrogen-mediated metabolites generate large quantities of local reactive oxygen species in the breast, which directly bind to mtDNA and facilitate neoplastic transformation. To further elucidate the molecular roles of mtDNA in breast cancer, we determined the oxidative status of a breast tumor cell line lacking mtDNA (T47D ρ⁰) and analyzed its susceptibility after exposure to various anticancer drugs as well as different proapoptotic signals. Our data showed that T47D ρ⁰ cells generated significantly increased levels of lactate with concomitantly reduced oxygen consumption and ATP production compared with the wild-type (WT). The amount of reactive oxygen species generation in ρ cells was lowered to approximately 12% that of parental cells, as evidenced by the oxidation of redox-sensitive probes. Although mtDNA depletion did not affect the expression of superoxide dismutase or its activity, the activities of antioxidant enzymes, catalase and glutathione peroxidase, were significantly higher in ρ⁰ cells compared with WT cells. In addition, mtDNA-depleted cells displayed a decreased sensitivity and accumulation of chemotherapeutic drugs (doxorubicin, vincristine, and paclitaxel), potentially because of the upregulated expression of multidrug resistance 1 (MDR1) gene and its product P-glycoprotein. When compared with their WT counterparts, T47D ρ⁰ cells were also more resistant to apoptosis induced by varying concentrations of staurosporine and anti-Fas antibody. Altogether, our results indicate the importance of intact mtDNA for maintaining the proper intracellular oxidative status. These data provide evidence for a possible role of mtDNA content reduction in acquiring an apoptosis-resistant phenotype during breast tumor progression and might contribute to effective therapeutic strategies for this common malignancy.

Recent studies revealed high ectopic beta protein 1 (BP1) expression in breast cancer. Remarkably, up to 100% (18/18) of estrogen receptor (ER)-negative tumors and 89% (25/28) of tumors from African American women were BP1-positive. However, the role of BP1 in breast cancer development and its clinical significance still has not been well defined. In the present study, we analyzed the quantitative level of BP1 mRNA in breast carcinomas using real-time polymerase chain reaction and aimed to elucidate its association with tumor characteristics and patient prognosis. Our data showed that BP1 mRNA was expressed at significantly higher levels in tumors with lymph node metastasis, with a high histological grade, and in those that were of ER-negative status. Furthermore, overexpression of BP1 was significantly associated with poor outcome of patients harboring tumors with a high histological grade and negative ER. Using both in vitro and in vivo systems, we also showed that the transcript level of BP1 was positively correlated to the growth rate of breast tumor cells. Taken together, our results support the notion that BP1 might contribute to breast neoplastic transformation or tumor progression and suggest for the first time that BP1 mRNA level has potential as a prognostic predictor for breast cancer.

Mitochondrial DNA (mtDNA) is known for its high frequencies of polymorphisms and mutations. The non-coding displacement (D)-loop, especially a mononucleotide repeat (poly-C) between 303 and 315 nucleotides (D310), has been recently identified as a frequent hotspot of mutations in human neoplasia, including breast cancer. To further explore the sequence variations of mitochondrial D-loop region in familial breast cancer and their possible associations with breast cancer risk, PCR-SSCP and direct DNA sequencing methods were used to detect the variants of the mtDNA D-Loop in 23 familial breast cancer patients as well as three high-risk cancer families. Compared to that in sporadic breast tumors (53.3%, 16/30) and healthy blood donors (6.7%, 2/30), we identified a total of 126 sequence alterations in 23/23 (100%) of familial breast cancer patients, including eight novel nucleotide variants. Among these changes, A to G at nt.263, T to C at nt.489, T to C at nt.310, TC insertion at nt.311, CA deletion at nt.522, and C to G at nt.527 were highly frequent ones. In addition, among three high-risk cancer families, we found that individuals affected with breast cancer harbored more mtDNA sequence variants in mtDNA D310 area than other affected family members. Together, our data indicate that sequence variants within the mtDNA D-Loop region are frequent events in Chinese familial breast cancer patients. Some of these nucleotide abnormalities, particularly those in D310 segment, might be involved in the breast carcinogenesis and could be included in a panel of molecular biomarkers for cancer susceptibility early-detection strategy.

Somatic mutations and large-scale depletion in mitochondrial DNA (mtDNA) have been extensively detected in various human cancers. However, it still remains unclear whether the alterations in mtDNA content are related to the clinicopathological parameters and patient prognosis in breast cancer. In the present study, we analyzed the copy number of mtDNA in 59 cases of invasive breast tumors and paired nontumorous tissues using quantitative real-time PCR. Our data showed that the level of mtDNA was significantly decreased in tumor tissues as compared to the adjacent nontumorous counterparts (P = 0.001). The reduced copy number in mtDNA was associated with an older onset age (>or=50 years old, P = 0.035) as well as a higher histological grade (P = 0.012). Survival analysis measured by the Kaplan-Meier curves and the log-rank test indicated that patients with reduced mtDNA content had significantly poorer disease-free survival (DFS, P = 0.0079) and overall survival (OS, P = 0.011) rate. In addition, tumors harboring mutations in displacement (D)-loop region, particularly at the polycytidine stretch (T/N ratio = 64.3 +/- 8.2%) or close to the replication origins of the heavy-strand (T/N ratio = 68.7 +/- 5.5%), had a significantly lower copy number of mtDNA than the ones without D-loop alterations. Together, our results suggested that reduced copy number of mtDNA may be involved in breast neoplastic transformation or progression and mtDNA content might be potentially used as a tool to predict prognosis. Somatic mutation in the D-loop region probably is one of key contributing factors leading to decreased mtDNA level in breast tumors.