Igor Snitcovsky

Gene Expression Profile Associated with Response to Doxorubicin-Based Therapy in Breast Cancer

Purpose: This study was designed to identify genes that could predict response to doxorubicin-based primary chemotherapy in breast cancer patients. Experimental Design: Biopsy samples were obtained before primary treatment with doxorubicin and cyclophosphamide. RNA was extracted and amplified and gene expression was analyzed using cDNA microarrays. Results: Response to chemotherapy was evaluated in 51 patients, and based on Response Evaluation Criteria in Solid Tumors guidelines, 42 patients, who presented at least a partial response (≥30% reduction in tumor dimension), were classified as responsive. Gene profile of samples, divided into training set (n = 38) and independent validation set (n = 13), were at first analyzed against a cDNA microarray platform containing 692 genes. Unsupervised clustering could not separate responders from nonresponders. A classifier was identified comprising EMILIN1, FAM14B, and PBEF, which however could not correctly classify samples included in the validation set. Our next step was to analyze gene profile in a more comprehensive cDNA microarray platform, containing 4,608 open reading frame expressed sequence tags. Seven samples of the initial training set (all responder patients) could not be analyzed. Unsupervised clustering could correctly group all the resistant samples as well as at least 85% of the sensitive samples. Additionally, a classifier, including PRSS11, MTSS1, and CLPTM1, could correctly distinguish 95.4% of the 44 samples analyzed, with only two misclassifications, one sensitive sample and one resistant tumor. The robustness of this classifier is 2.5 greater than the first one. Conclusion: A trio of genes might potentially distinguish doxorubicin-responsive from nonresponsive tumors, but further validation by a larger number of samples is still needed.

Antiproliferative effects of 1,25-dihydroxyvitamin D3 on breast cells: a mini review

The hormone 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3), the active form of vitamin D3, is an important regulator of calcium homeostasis, exerts antiproliferative effects on various cell systems and can induce differentiation in some kinds of hematopoietic cells. These effects are triggered by its receptor, vitamin D receptor (VDR), a phosphoprotein member of the nuclear receptor superfamily, which functions as a transcriptional factor. VDR binds as a heterodimer with retinoid X receptor (R X R) to hexameric repeats, characterized as vitamin D-responsive elements present in the regulatory region of target genes such as osteocalcin, osteopontin, calbindin-D28K, calbindin-D9K, p21WAF1/CIP1, TGF-beta2 and vitamin D 24-hydroxylase. Many factors such as glucocorticoids, estrogens, retinoids, proliferation rate and cell transformation can modulate VDR levels. VDR is expressed in mammary tissue and breast cancer cells, which are potential targets to hormone action. Besides having antiproliferative properties, vitamin D might also reduce the invasiveness of cancer cells and act as an anti-angiogenesis agent. All of these antitumoral features suggest that the properties of vitamin D could be explored for chemopreventive and therapeutic purposes in cancer. However, hypercalcemia is an undesirable side effect associated with pharmacological doses of 1,25-(OH)2D3. Some promising 1,25-(OH)2D3 analogs have been developed, which are less hypercalcemic in spite of being potent antiproliferative agents. They represent a new field of investigation.

ERCC1 protein, mRNA expression and T19007C polymorphism as prognostic markers in head and neck squamous cell carcinoma patients treated with surgery and adjuvant cisplatin-based chemoradiation

Adjuvant cisplatin-based chemoradiation improves survival in HNSCC patients presenting with risk features. ERCC1 (excision repair cross-complementation group 1) is associated with resistance to chemo- and radiation therapy and may have a prognostic value in HNSCC patients. Here we studied ERCC1 expression and the polymorphism T19007C as prognostic markers in these patients. This is a retrospective and translational analysis, where ERCC1 protein expression was evaluated by immunohistochemistry, using an H-score, and mRNA expression was determined by RT-PCR. T19007C genotypes were detected by PCR-RFLP carried out using DNA template extracted from normal lymph nodes. A high H-score was seen in 32 patients (54%), who presented better 5-year overall survival (5-y OS: 50% vs. 18%, HR 0.43, p=0.026). Fifteen out of 45 patients (33%), with high mRNA expression, presented better 5-year overall survival (OS) (86% vs. 30%, HR 0.26, p=0.052). No OS difference was detected among T19007C genotypes. High H-score and mRNA expression remained significant as favorable prognostic factors in a multivariate analysis. Collectively, our results suggest that high ERCC1 expression seems to be associated with better OS rates in HNSCC patients submitted to adjuvant cisplatin-based chemoradiation.

Smad2 and Smad6 as predictors of overall survival in oral squamous cell carcinoma patients

BackgroundTo test if the expression of Smad1-8 mRNAs were predictive of survival in patients with oral squamous cell carcinoma (SCC).Patients and MethodsWe analyzed, prospectively, the expression of Smad1-8, by means of Ribonuclease Protection Assay in 48 primary, operable, oral SCC. In addition, 21 larynx, 10 oropharynx and 4 hypopharynx SCC and 65 matched adjacent mucosa, available for study, were also included. For survival analysis, patients were categorized as positive or negative for each Smad, according to median mRNA expression. We also performed real-time quantitative PCR (QRTPCR) to asses the pattern of TGFβ1, TGFβ2, TGFβ3 in oral SCC.ResultsOur results showed that Smad2 and Smad6 mRNA expression were both associated with survival in Oral SCC patients. Cox Multivariate analysis revealed that Smad6 positivity and Smad2 negativity were both predictive of good prognosis for oral SCC patients, independent of lymph nodal status (P = 0.003 and P = 0.029, respectively). In addition, simultaneously Smad2- and Smad6+ oral SCC group of patients did not reach median overall survival (mOS) whereas the mOS of Smad2+/Smad6- subgroup was 11.6 months (P = 0.004, univariate analysis). Regarding to TGFβ isoforms, we found that Smad2 mRNA and TGFβ1 mRNA were inversely correlated (p = 0.05, R = -0.33), and that seven of the eight TGFβ1+ patients were Smad2-. In larynx SCC, Smad7- patients did not reach mOS whereas mOS of Smad7+ patients were only 7.0 months (P = 0.04). No other correlations were found among Smad expression, clinico-pathological characteristics and survival in oral, larynx, hypopharynx, oropharynx or the entire head and neck SCC population.ConclusionSmad6 together with Smad2 may be prognostic factors, independent of nodal status in oral SCC after curative resection. The underlying mechanism which involves aberrant TGFβ signaling should be better clarified in the future.

Molecular targets of 1,25(OH)2D3 in HC11 normal mouse mammary cell line

Our aim was to determine the molecular targets involved in the antiproliferative effects of 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)), in a normal murine mammary epithelial cell line, HC11. Among the early response genes analyzed, c-myc, junB, junD, c-jun, c-fos, fosB, fra, as well as max, mad1-4, sin3, only c-jun and fra-2 mRNAs were up-regulated after 1,25(OH)(2)D(3) exposure. Cyclin C was reduced and cyclin A2 and E were slightly enhanced; however, cyclins D1, D3, B1, B2, F, G1, G2, I and H, as well as TGF beta 1, TGF beta 3, T beta RI and T beta RII transcripts were not modulated by 1,25(OH)(2)D(3). Although p27(KIP1) protein content was unchanged, enhancement of p21(WAF1/CIP1) low basal levels in cell extracts and IGFBP-3 abundance on the culture medium was detected after 1,25(OH)(2)D(3) induction. Using differential display analysis, we identified eight down-modulated clones in exposed cells: 26S proteasome non-ATPase subunit Pad1, ubiquitin-conjugating enzyme Ube2i, extracellular proteinase inhibitor Expi or Wdnm1, cytochrome-c oxidase Cox7c, microtubule-associated protein-1 light chain-3 (Map1lc3), nascent-associated complex alpha Naca, transforming acidic coiled-coil Tacc3, stearoyl-CoA desaturase (Scd), keratin 6 alpha, and 1 up-regulated, fork head transcription factor Hfh-1L. Hence, the antiproliferative effect of 1,25(OH)(2)D(3) seems associated to enhancement of c-jun, Fra-2, IGFBP3 and p21(WAF1/CIP1). Decreased Pad1 and Ube2i might account for increased stability of cell cycle inhibitory proteins while reduced Wdnm1, Tacc3 and Scd might be secondary to accumulation of cells in G0/G1 phase.

Plasma Osteopontin Levels in Patients With Head and Neck Cancer Undergoing Chemoradiotherapy

OBJECTIVES To explore the prognostic role of plasma levels of osteopontin (OPN), a phosphoglycoprotein with adhesive properties, in patients with head and neck squamous cell carcinoma (HNSCC) undergoing concomitant chemoradiotherapy. Previous studies have proposed OPN level as a prognostic factor in several cancers. DESIGN Prospective analysis of plasma OPN levels, before and within 12 weeks after treatment, in a cohort of patients with HNSCC undergoing platinum-based chemoradiotherapy at our center. SETTING Academic center. PATIENTS Sixty-nine patients diagnosed as having HNSCC. INTERVENTIONS Plasma levels of OPN were assessed before the start and after the conclusion of chemoradiotherapy by using an enzyme-linked immunosorbency assay kit. Chemoradiotherapy was exclusive (n = 52) or adjuvant to surgery (n = 17). MAIN OUTCOME MEASURES Levels of OPN were correlated with clinicopathological characteristics, response to treatment, and overall survival. RESULTS Pretreatment plasma OPN levels were higher in patients with advanced T and N stages compared with patients with early stages (P = .009 and .07, respectively). Mean (SD) plasma levels of OPN measured before (102.5 [68.1] ng/mL) and after (104.0 [53.6] ng/mL) treatment did not differ (P = .18, paired t test). Pretreatment and posttreatment levels of OPN were lower in patients who achieved a complete response compared with those who failed to respond (75.0 [41.5] vs 131.2 [82.9] ng/mL [P = .005] and 86.8 [40.5] vs 141.6 [58.4] ng/mL [P = .004], respectively). Patients with high pretreatment OPN levels (>82.1 ng/mL) had shorter survival time (P < .001). Posttreatment OPN levels were marginally (P = .10) associated with survival time in univariate analysis. CONCLUSIONS In patients with HNSCC undergoing chemoradiotherapy, a low pretreatment plasma OPN level is associated with treatment response and better survival. Modulation of OPN levels by chemoradiotherapy may also be associated with outcome. Further studies with serial measurement of OPN levels are warranted in these patients.

Four-gene expression model predictive of lymph node metastases in oral squamous cell carcinoma

Abstract Background. Previous knowledge of cervical lymph node compromise may be crucial to choose the best treatment strategy in oral squamous cell carcinoma (OSCC). Here we propose a set four genes, whose mRNA expression in the primary tumor predicts nodal status in OSCC, excluding tongue. Material and methods. We identified differentially expressed genes in OSCC with and without compromised lymph nodes using Differential Display RT-PCR. Known genes were chosen to be validated by means of Northern blotting or real time RT-PCR (qRT-PCR). Thereafter we constructed a Nodal Index (NI) using discriminant analysis in a learning set of 35 patients, which was further validated in a second independent group of 20 patients. Results. Of the 63 differentially expressed known genes identified comparing three lymph node positive (pN +) and three negative (pN0) primary tumors, 23 were analyzed by Northern analysis or RT-PCR in 49 primary tumors. Six genes confirmed as differentially expressed were used to construct a NI, as the best set predictive of lymph nodal status, with the final result including four genes. The NI was able to correctly classify 32 of 35 patients comprising the learning group (88.6%; p = 0.009). Casein kinase 1alpha1 and scavenger receptor class B, member 2 were found to be up regulated in pN + group in contrast to small proline-rich protein 2B and Ras-GTPase activating protein SH3 domain-binding protein 2 which were upregulated in the pN0 group. We validated further our NI in an independent set of 20 primary tumors, 11 of them pN0 and nine pN + with an accuracy of 80.0% (p = 0.012). Conclusions. The NI was an independent predictor of compromised lymph nodes, taking into the consideration tumor size and histological grade. The genes identified here that integrate our “Nodal Index” model are predictive of lymph node metastasis in OSCC.

ERCC1 protein, mRNA expression, and T19007C polymorphism as prognostic markers in head and neck squamous cell carcinoma (HNSCC) patients treated with surgery and adjuvant cisplatin-based chemoradiation (CRT).

5540 Background: Adjuvant cisplatin-based CRT improves overall survival (OS) in some HNSCC patients (pts) presenting with risk features, but toxicity is not negligible. ERCC1 is involved in NER pathway and is associated with resistance to chemo- and RT. We studied ERCC1 expression and the SNP T19007C in these pts. Methods: It is a retrospective study in HNSCC pts submitted to surgery and presenting with pathologic risk features. They were treated with 60-70 Gy and concurrent cisplatin 100 mg/m2d1, 22, 43. ERCC1 protein, mRNA expression and the SNP were studied in archived tissue blocks. ERCC1 expression was evaluated by immunohistochemistry, using a semi-quantitative H- score, and its mRNA expression was determined by quantitative RT-PCR. T19007C genotypes were detected using PCR-RFLP carried out in genomic DNA extracted from normal lymph nodes. Results: 69 pts (median age 56 y, 81% male) were studied. Primary sites: oral cavity 41%, larynx 32%, hypopharynx 16%, oropharynx 12%; stage IV 86%, pT3-pT4 78% a...

CCR2-64I polymorphism and head and neck squamous cell carcinoma

OBJECTIVES: From the differential expression profiles between paired nasopharyngeal carcinoma (NPC) and pericancerous normal epithelium analyzed by cDNA microarray technology, we have found that CCL20 might be a potential biomarker. Since CCL20 is a secretory protein, we herein further examine whether it could be used as a serum marker for NPC detection and correlated with prognosis. METHODS: The study enrolled a prospective and a retrospective cohort, which totally comprises 275 NPC patients and 250 controls. CCL20 levels in sera were measured by ELISA. EBV DNA load and EBV VCA IgA were measured by qRT-PCR and immunofluorescent assay, respectively. RESULTS: Serum CCL20 levels were significantly higher in untreated patients, recurrent patients and patients with distant metastases versus non-NPC controls, patients with complete remission, and long-term disease-free patients. Serum CCL20 levels were significantly higher in untreated NPC patients with advanced TNM stage. Measurement of CCL20, EBV DNA and VCA IgA levels in serial serum/plasma samples from treated patients at six-month intervals revealed a high association between CCL20 serum level and disease status. Among 155 consecutive NPC patients, subjects with pre-treated CCL20 serum levels over 65 pg/ml had worse prognoses for overall survival and distant metastasis-free survival in univariate and multivariate analysis. CONCLUSIONS: In this study, we found that serum CCL20 levels were positively correlated with the current state-of-art NPC marker, EBV DNA load, implying its potential correlated with NPC tumor burden. CCL20 might be a novel serum marker for NPC detection and prediction of treatment outcome.

Possible role for chemokine receptor CCR7 mRNA expression in lymph node metastasis in head and neck squamous cell carcinoma

9677 Background: Chemokine receptor-ligand interactions may play a role in the spread of Head and Neck Squamous Cell Carcinomas to regional lymph nodes. METHODS In this work, we have analyzed the mRNA expression of chemokine receptors (CXCR1-5, CCR7 and CX3CR1), by Ribonuclease Protection Assay (Riboquant RPA system, Pharmingen), in fragments of primary tumor (T), normal adjacent mucosa (M) of 39 patients (pts) with operable HNSCC. These data and of 10 grossly compromised lymph nodes (LN) were correlated with clinical-pathological parameters. RESULTS Primary tumors, when compared to normal adjacent matched mucosa (n=37), showed higher CXCR4 mRNA expression (T: 0.216 ± 0.116 vs 0.139 ± 0.128:M, p=0.003, t-test paired). Considering all sites, we did not find differences between pN0 (n=16) vs pN+ (n=22) primary tumors. Compromised lymph nodes LN (n=10), as compared to matched primary tumors, expressed higher CCR7 mRNA densitometric values: (LN:0.054 ± 0.064 vs 0.007 ± 0.008:T, p = 0.044). CONCLUSIONS Chemokine receptor CXCR4 mRNA expression was significantly higher in tumors, as compared to normal adjacent mucosa. In addition, chemokine receptor CCR7, presented higher mRNA expression in compromised LN as compared to matched primary tumors. We conclude that these receptors are, respectively, candidate markers of neoplastic transformation and spread to lymph nodes in HNSCC. Further studies are warranted in this area to confirm these results. No significant financial relationships to disclose.