Tau protein as a potential predictive marker in epithelial ovarian cancer patients treated with paclitaxel/platinum first-line chemotherapy

Background

The aim of the study was to evaluate predictive and prognostic significance of microtubule-associated protein Tau in epithelial ovarian cancer (EOC) patients treated with paclitaxel and platinum-based chemotherapy.

Methods

74 patients with EOC (stage I-IV) who underwent cytoreductive surgery followed by standard paclitaxel/platinum chemotherapy were included in the retrospective analysis. Their formalin-fixed, paraffin-embedded tissue specimens were immunohistochemically stained for Tau protein, using semi-quantitative DAKO test. Tau expression was acknowledged as negative (0 and 1+) or positive (2+ and 3+). The correlation between Tau expression, progression free survival (PFS) and overall survival (OS) was evaluated. Statistical analysis included Kaplan-Meyer estimator, long rank test, Mann Whitney test and Cox proportional hazards model.

Results

25.7% (19/74) and 74.3% (55/74) of the patients were classified as Tau-negative and Tau-positive, respectively. Median PFS was 28.7 months for Tau-negative group and 15.9 months for Tau-positive group (p = 0.0355). In the univariate analysis 3-year OS in Tau-negative and Tau-positive groups was 80.2% and 52.4%, respectively (p = 0.0198). Low expression of protein Tau was associated with better OS, whereas an advanced stage at diagnosis, suboptimal surgery, serous histological type and resistance to first line chemotherapy were each correlated with worse OS (p <0,05). In multivariate analysis only resistance to first line chemotherapy remained significant (HR 22.59; 95% CI, 8.71-58.55; p <0.0001).

Conclusions

Negative tau protein seems to be both good prognostic factor and a predictor of response to paclitaxel/platinum-based chemotherapy in EOC patients.     

Genome-wide cDNA microarray analysis of gene-expression profiles involved in ovarian endometriosis

Using a cDNA microarray consisting of 23,040 genes, we analyzed gene-expression profiles of ovarian endometrial cysts from 23 patients in order to identify genes involved in endometriosis. By comparing expression patterns between endometriotic tissues and corresponding eutopic endometria, we identified 15 genes that were commonly up-regulated in the endometrial cysts during both proliferative and secretory phases of the menstrual cycle, 42 that were up-regulated only in the proliferative phase, and 40 that were up-regulated only in the secretory phase. The up-regulated elements included genes encoding some HLA antigens, complement factors, ribosomal proteins, and TGFBI. On the other hand, 337 genes were commonly down-regulated throughout the menstrual cycle, 144 only in the proliferative phase, and 835 only in the secretory phase. The down-regulated elements included the tumor suppressor TP53, genes related to apoptosis such as GADD34, GADD45A, GADD45B and PIG11, and the gene encoding OVGP1, a protein involved in maintenance of early pregnancy. Semi-quantitative RT-PCR experiments supported the results of our microarray analysis. These data should provide useful information for finding candidate genes whose products might serve as molecular targets for diagnosis or treatment of endometriosis.     

High-temperature-required protein A2 as a predictive marker for response to chemotherapy and prognosis in patients with high-grade serous ovarian cancers

Background:

High-temperature-required protein A2 (HtrA2), a protein relating with apoptosis in a caspases-dependent and non-dependent manner, has been reported to be associated with chemosensitivity in several human cancers.

Methods:

Tissue microarrays made from 142 patients with high-grade serous ovarian adenocarcinoma were evaluated to assess whether HtrA2 expression was related with several clinical parameters.

Results:

Negative HtrA2 expression was observed in 36 cases (25%) of the patients, and related with significantly lower response rates of primary chemotherapy than those with positive HtrA2 expression (56% vs 83%, P<0.01). In addition, negative HtrA2 expression was identified as an independent worse prognostic factor for progression-free survival and overall survival by multivariate analyses. Furthermore, HtrA2 downregulation modulated sensitivity to platinum in serous ovarian cancer cells in vitro.

Conclusions:

HtrA2 expression was a predictor for sensitivity to chemotherapy, and could be a candidate of molecular target in the treatment of high-grade serous ovarian cancers.     

Gene expression profiling of luminal B breast cancers reveals NHERF1 as a new marker of endocrine resistance

The luminal B subtype represents a group of high proliferating estrogen receptor positive breast cancers which are associated with a poor prognosis. Genes exclusively expressed in this subtype should help to better understand these tumors. In a finding cohort of 171 breast cancers luminal B specific genes were identified displaying strong expression in highly proliferating Ki-67 positive/ER positive tumors but no expression either in Ki-67 negative/ER positive or in Ki-67 positive/ER negative samples. The clinical relevance of the scaffold protein NHERF1 identified by this strategy was assessed in a total of 3,030 breast cancers. NHERF1 expression was associated with the luminal B subtype both in the finding and validation cohort. A positive correlation of NHERF1 expression with tumor size (P < 0.001), grade (P < 0.001), and HER2 status (P = 0.033) was observed. NHERF1 expression was associated with a worse survival in ER positive breast cancer (P < 0.001) and retained its prognostic value in multivariate analysis. For ER positive samples with low NHERF1 expression a benefit of endocrine therapy was detected (P = 0.007). In contrast no differences in disease free survival were found for high NHERF1 expressing breast cancers which were either treated with endocrine therapy or no systemic therapy. Our data indicate that NHERF1 expressing breast cancers seem to have a greater risk to develop resistance to endocrine therapy. However, based on previous findings of NHERF1 functioning in PI3K signalling from basic research, these tumors might be appropriate candidates for a targeted therapy of the PI3K/Akt pathway.     

Comparison of gene-expression profiles between diffuse- and intestinal-type gastric cancers using a genome-wide cDNA microarray

Gastric cancer is the fourth leading cause of cancer-related death in the world. Two histologically distinct types of gastric carcinoma, 'intestinal' and 'diffuse', have different epidemiological and pathophysiological features that suggest different mechanisms of carcinogenesis. A number of studies have investigated intestinal-type gastric cancers at the molecular level, but little is known about mechanisms involved in the diffuse type, which has a more invasive phenotype and poorer prognosis. To clarify the mechanisms that underlie its development and/or progression, we compared the expression profiles of 20 laser-microbeam-microdissected diffuse-type gastric-cancer tissues with corresponding noncancerous mucosae by means of a cDNA microarray containing 23,040 genes. We identified 153 genes that were commonly upregulated and more than 1500 that were commonly downregulated in the tumors. We also identified a number of genes related to tumor progression. Furthermore, comparison of the expression profiles of diffuse-type with those of intestinal-type gastric cancers identified 46 genes that may represent distinct molecular signatures of each histological type. The putative signature of diffuse-type cancer exhibited altered expression of genes related to cell-matrix interaction and extracellular-matrix (ECM) components, whereas that of intestinal-type cancer represented enhancement of cell growth. These data provide insight into different mechanisms underlying gastric carcinogenesis and may also serve as a starting point for identifying novel diagnostic markers and/or therapeutic targets for diffuse-type gastric cancers.     

Classification of sensitivity or resistance of cervical cancers to ionizing radiation according to expression profiles of 62 genes selected by cDNA microarray analysis

To identify a set of genes related to radiosensitivity of cervical squamous cell carcinomas and to establish a predictive method, we compared expression profiles of 9 radiosensitive and 10 radioresistant tumors obtained by biopsy before treatment, on a cDNA microarray consisting of 23,040 human genes. We identified 121 genes whose expression was significantly greater in radiosensitive cells than in radioresistant cells, and 50 genes that showed higher levels of expression in radioresistant cells than in radiosensitive cells. Some of these genes had already known to be associated with the radiation response, such as aldehyde dehydrogenase 1 (ALDH1) and X-ray repair cross-complementing 5 (XRCC5) (P<.05, Mann-Whitney test). The validity of the total of 171 genes as radiosensitivity related genes were certified by permutation test (P<.05). Furthermore, we selected 62 genes on the basis of a clustering analysis, and confirmed the validity of these genes with cross-validation test. The cross-validation test also indicates the possibility of making prediction of radiosensitivity for discriminating radiation-sensitive from radiation resistant biopsy samples by predicting score (PS) values calculated from expression values of 62 genes in 19 samples, because the prediction successfully and unequivocally discriminated the radiosensitive phenotype from the radioresistant phenotype in our test panel of 19 cervical carcinomas. The extensive list of genes identified in these experiments provides a large body of potentially valuable information for studying the mechanism(s) of radiosensitivity, and selected 62 genes opens the possibility of providing appropriate and effective radiotherapy to cancer patients.     

Identification of secernin 1 as a novel immunotherapy target for gastric cancer using the expression profiles of cDNA microarray

Despite the discovery of multiple TAAs, only a limited number is available for clinical application, particularly against epithelial malignancies. In this study we searched for novel TAAs using expression profiles of gastric cancer examined with cDNA microarray, and identified the SCRN1 gene as a candidate. SCRN1 was confirmed to be expressed in five out of seven gastric cancers with semiquantitative RT-PCR. With Northern blot analysis, it was detected abundantly in the testis and ovary, but it was barely detectable in 14 other normal human adult organs. Colony formation assay revealed that its augmented expression is associated with promoted cell growth. As these expression profiles and functional features of SCRN1 appeared to be compatible with the characteristics of the hypothesized ideal TAAs, we examined whether SCRN1 protein contains antigenic epitope peptides restricted to HLA-A*0201. We synthesized the candidate peptides derived from SCRN1, and tried to induce CTLs with each peptide. The CTL clones were successfully induced with a peptide SCRN1-196 (KMDAEHPEL), and they lyzed not only the peptide-pulsed targets but also the tumor cells expressing both SCRN1 and HLA-A*0201 endogenously. These results strongly suggest that SCRN1-196 is an epitope peptide restricted to HLA-A*0201. Furthermore, we synthesized an anchor-modified peptide SCRN1-9 V (KMDAEHPEV), in which leucine at position 9 was substituted for valine to increase the binding affinity to the HLA-A*0201 molecules. The CTL clones induced by SCRN1-9 V also recognized tumor cells expressing its natural SCRN1 protein endogenously. These results strongly suggest that SCRN1 is a novel TAA and these peptides, both native and modified, may be applicable for cancer vaccines to treat gastric cancer.     

Gene expression profiling in polycythemia vera using cDNA microarray technology

Polycythemia vera (PV) is a myeloproliferative disorder characterized by an increased proliferation of all three myeloid lineages. The molecular pathogenesis of PV is unknown. Using cDNA microarrays comprising 6000 human genes, we studied the gene expression profile of granulocytes obtained from 11 PV patients compared with granulocytes obtained from healthy individuals. We found that 147 genes were up-regulated by >/==" BORDER="0">2.5 fold in the majority of PV patients. Eleven of these 147 genes were up-regulated in all PV patients studied and may represent a molecular signature for this disorder. An increase in the expression of several protease inhibitors with affinity for proteases that promote apoptosis in neutrophils (e.g., cystatin F, secretory leukocyte protease inhibitor), as well as the up-regulation of a number of antiapoptotic and survival factors was found (e.g., adrenomedullin, p38 mitogen-activated protein kinase). We speculate that the deregulation of these factors may inhibit normal apoptosis and promote cell survival in the granulocytes of patients with PV. These PV-specific expression changes are likely to be biologically important in the pathophysiology of this disorder.     

BubR1 as a prognostic marker for recurrence-free survival rates in epithelial ovarian cancers

Background:

Epithelial ovarian cancer is one of the most lethal malignancies, and has a high recurrence rate. Thus, prognostic markers for recurrence are crucial for the care of ovarian cancer. As ovarian cancers frequently exhibit chromosome instability, we aimed at assessing the prognostic significance of two key mitotic kinases, BubR1 and Aurora A.

Methods:

We analysed paraffin-embedded tissue sections from 160 ovarian cancer patients whose clinical outcomes had been tracked after first-line treatment.

Results:

The median recurrence-free survival in patients with a positive and negative expression of BubR1 was 27 and 83 months, respectively (P<0.001). A positive BubR1 expression was also associated with advanced stage, serous histology and high grade. In contrast, Aurora A immunostaining did not correlate with any of the clinical parameters analysed.

Conclusion:

BubR1, but not Aurora A, is a prognostic marker for recurrence-free survival rates in epithelial ovarian cancers.     

Gene expression profiles in human non-small and small-cell lung cancers

Suppression subtractive hybridisation (SSH) was performed comparing normal bronchial epithelial cells with a lung squamous cell carcinoma (SCC) and a metastatic small-cell lung carcinoma (SCLC). The sequence analysis of four cDNA libraries revealed 869 individual sequences. Of these, 342 were tested using northern blots of lung cancer cell lines representing the three major subtypes (SCC, adenocarcinoma, SCLC) which confirmed the differential expression of 236 cDNAs. The extended analysis of 31 randomly chosen fragments confirmed the validity of the approach to identify genes associated with lung cancer development. Additionally, five novel full-length cDNA were isolated encoding the microtubule-associated proteins 1A/1B light chain 3, the epithelial V-like antigen 1 (EVA1), the GTP-binding protein SAR1, a new member of the S100-type calcium binding protein family and a new homeobox-containing gene.     

RANK expression as a prognostic and predictive marker in breast cancer

RANK ligand (RANKL) is crucial for the development of mouse mammary glands during pregnancy. RANKL functions as a major paracrine effector of the mitogenic action of progesterone in mammary epithelium via its receptor RANK and has a role in expansion and regenerative potential of mammary stem cells. Pharmacologic inhibition of RANKL attenuates the development of mammary carcinoma and inhibits metastatic progression in multiple mouse models. Primary breast carcinoma samples from the neoadjuvant GeparTrio study were analyzed to correlate the expression of human RANK and RANKL with pathological complete response (pCR), disease-free (DFS), and overall (OS) survival. Pre-treatment FFPE core biopsies (n = 601) were analyzed for percentage and intensity of immunohistochemical RANK and RANKL expression. Antibodies against human RANK (N-1H8; Amgen) and human RANKL (M366; Amgen) were used. RANK protein was expressed in 160 (27 %) patients. Increased RANK expression was observed in 14.5 % of patients and correlated with high tumor grade (p < 0.023) and negative hormone receptor (HR) status (p < 0.001). Patients with high RANK expression showed a higher pCR rate (23.0 % vs. 12.6 %, p = 0.010), shorter DFS (p = 0.038), and OS (p = 0.011). However, prognostic and predictive information was not an independent parameter. Only 6 % of samples expressed RANKL, which was not correlated with any clinical features. Higher RANK expression in the primary tumor is associated with a higher sensitivity to chemotherapy, but also a higher risk of relapse and death. Our study provides a basis for further exploration of the antitumor activity of clinical antibodies against RANKL.     

Gene expression profiles of human melanoma cells with different invasive potential reveal TSPAN8 as a novel mediator of invasion

Background:

Metastatic melanoma requires early detection, being treatment resistant. However, the earliest events of melanoma metastasis, and especially of dermal invasion, remain ill defined.

Results and methods:

Gene expression profiles of two clonal subpopulations, selected from the same human melanoma cell line, but differing in ability to cross the dermal–epidermal junction in skin reconstructs, were compared by oligonucleotide microarray. Of 26 496 cDNA probes, 461 were differentially expressed (>2-fold; P< 0.001), only 71 genes being upregulated in invasive cells. Among them, TSPAN8, a tetraspanin not yet described in melanoma, was upregulated at mRNA and protein levels in melanoma cells from the invasive clone, as assessed by RT–PCR, flow cytometry and western blot analysis. Interestingly, TSPAN8 was the only tetraspanin in which overexpression correlated with invasive phenotype. Flow cytometry of well-defined melanoma cell lines confirmed that TSPAN8 was exclusively expressed by invasive, but not non-invasive melanoma cells or normal melanocytes. Immunohistochemistry revealed that TSPAN8 was expressed by melanoma cells in primary melanomas and metastases, but not epidermal cells in healthy skin. The functional role of TSPAN8 was demonstrated by silencing endogenous TSPAN8 with siRNA, reducing invasive outgrowth from tumour spheroids within matrigel without affecting cell proliferation or survival.

Conclusion:

TSPAN8 expression may enable melanoma cells to cross the cutaneous basement membrane, leading to dermal invasion and progression to metastasis. TSPAN8 could be a promising target in early detection and treatment of melanoma.     

用高密度cDNA微阵列技术检测鼻咽癌差异表达基因

背景与目的：鼻咽癌的发生与发展涉及多个步骤,多个因素的参与,对此目前尚缺乏了解,本研究试图通过大规模检测鼻咽癌的基因差异表达来揭示鼻咽癌的差异表达基因谱,以发现与鼻咽癌发生,发展相关的新的候选基因。方法：用由18000个基因构建的高密度cDNA微阵列对21例鼻咽癌分3个样本池分别检测并与鼻咽非癌组织作对比分析。随机选2个基因用半定量RT－PCR验证检测结果。结果：3个样本池鼻咽癌差异表达基因分别为186个,95个和36个,总数达317个,表达上调的277个,表达下调的40个,差异表达基因中2个样本池以上有共同差异表达的基因有23个,表达上调的16个,表达下调的7个,其中3个样本池表达均有差异者6个,5个上调,1个下调,5个上调的基因中2个是已知基因,3个是未知基因,1个下调的是未知基因。结论：本研究揭示了鼻咽癌的基因表达谱,为了解鼻咽癌发生,发展的分子机理提供了大量信息,为寻找鼻咽癌相关基因提供了重要线索。     

Midkine as a potential diagnostic marker in epithelial ovarian cancer for cisplatin/paclitaxel combination clinical therapy

The paclitaxel/cisplatin combination therapy commonly is used as the first-line treatment for advanced ovarian cancer patients. Midkine (MK), known as a novel tumor biomarker, has been elevated in the serum of patients with epithelial ovarian cancer (EOC). In this study, we aimed to detect the expression of MK in EOC tissues and evaluate clinical value of MK in diagnosis and therapy of EOC. We perform immunohistochemistry analysis to detect MK in EOC sample with postoperative platinum/paclitaxel combination therapy, we found that 71.4% (85 in 119 samples) of these samples were MK positive (> 10% of the cells were stained), and the expression of MK was significantly associated with disease histology (P = 0.038) as well as differentiation grade (P < 0.001). Moreover, MK positive samples show much more sensitive to cisplatin/paclitaxel combination therapy, compared with MK negative samples (P = 0.029). Those results indicated that MK expression might correlate with paclitaxel and/or cisplatin cytotoxicity in clinical therapy of EOC. Then, we evaluated the sensitivity to cisplatin and paclitaxel in 5 ovarian cancer cell lines (ES2, A2870, HO-8910, SKOV3 and SW626), and ES2, the highest MK expression among those cell lines, show the most sensitive to paclitaxel and cisplatin. Further, we confirmed this correlation between MK and paclitaxel and/or cisplatin cytotoxicity with the gain- and lost- of function. Finally, we demonstrated that MK enhanced the cytotoxicity of paclitaxel and/or cisplatin by accumulated cisplatin and paclitaxel through inhibited the expression of multidrug resistance-associated protein 3 (MRP3). In conclusion, MK could be an effective biomarker in diagnosis and therapy of EOC, especially for the drug selection at the time of initial diagnosis.     

Association of GSTP1 expression with resistance to docetaxel and paclitaxel in human breast cancers

Aims

It has been reported that glutathione S-transferase P1 (GSTP1) expression is implicated in resistance to taxanes (docetaxel and paclitaxel) in human breast cancer cells in vitro. In the study presented here, we examine whether GSTP1 expression is associated with resistance to docetaxel or paclitaxel in human breast cancers. We also investigated the relationship between GSTP1 methylation status and response to these taxanes.

Material and methods

Sixty two primary breast cancer patients were treated with docetaxel or paclitaxel as primary systemic treatment (PST). GSTP1 expression was detected immunohistochemically and the hypermethylation status GSTP1 gene was identified with a methylation specific primer assay.

Results

The mean tumor reduction rate for all patients (n = 62) was significantly (p < 0.001) higher in GSTP1 negative (0.73 ± 0.04; mean ± standard error) than GSTP1 positive (0.31 ± 0.09) tumors. The subset analysis showed that the mean reduction rate was significantly (p = 0.005) higher in GSTP1 negative (0.59 ± 0.06) than GSTP1 positive (0.11 ± 0.13) tumors in the docetaxel group as well as in the paclitaxel group (p = 0.006; GSTP1 negative tumors: 0.84 ± 0.05; GSTP1 positive tumors: 0.56 ± 0.08). On the other hand, GSTP1 methylation showed no significant association with the reduction rate.

Conclusion

Our present study has suggested that GSTP1 protein expression, but not GSTP1 methylation status, might be associated with response to docetaxel and paclitaxel. This suggests that GSTP1 immunohistochemical expression might be a potentially clinically useful predictive factor for response to docetaxel and paclitaxel.     

Genome-scale analysis of resveratrol-induced gene expression profile in human ovarian cancer cells using a cDNA microarray

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a natural compound found in large quantities, most notably in grapes and red wine, which has been shown to have anti-inflammatory, chemopreventive and anti-angiogenic effects. We examined whether resveratrol has any effect on growth and gene expression in the human ovarian cancer PA-1 cells. We show that resveratrol inhibits cell growth and induces apoptosis in PA-1 human ovarian cancer cells. We also investigated the effect of resveratrol on changes of global gene expression during resveratrol-induced growth inhibition and apoptosis in PA-1 cells using a human cDNA microarray with 7,448 sequence-verified clones. Out of the 7,448 genes screened, 118 genes were founded to be affected in their expression levels by more than 2-fold after 24-h treatment with 50 micro M resveratrol. Resveratrol treatment of PA-1 cells at the final concentration of 50 micro M for 6, 12, 24 and 48 h and gene expression patterns were analyzed by microarray. Clustering of the genes modulated more than 2-fold at three of the above times points divided the genes into 2 groups. Within these groups, there were specific subgroups of genes whose expressions were substantially changed at the specified time points. One of the most highly up-regulated genes found in this study was NAD(P)H quinone oxidoreductase 1(NQO-1), which has recently been shown to be involved in p53 regulation. Although the precise roles of genes whose expression levels were found to fluctuate after resveratrol treatment remain to be elucidated, we hope that the new view of gene expression in human ovarian cancer cells following resveratrol exposure, as offered by this study, provides clues for the mechanism of resveratrol action.