Unknown,Transcriptomics,Genomics,Proteomics

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Gene expression profile of N+ and N0 HNSCC

ABSTRACT: Head and neck squamous cell carcinomas (HNSCCs) is the seventh most common solid malignancy in the United States, accounting for more than 47,000 new cancer cases. Surgery of patients clinically diagnosed with lymph node metastasis (N+) also involves neck dissection, which causes disfigurement and pain. However, after histological examination, more than 30% of clinically N+ patients turn out to be metastasis-free (N0). Clinically negative lymph node patients have occult node metastasis in up to 50% of the cases. Within two years of follow-up these patients may or may not develop metastatic disease. On the other hand, around 50% of N0 patients do not have occult node metastasis. Therefore, many N0 patients undergo neck dissection unnecessarily. Due to limitations in detecting lymph node metastasis before surgery, both N+ and N0 patients may receive inappropriate treatment. This indicates that a better understanding of the biology of HNSCC is urgently needed. Despite tumor complexity, many studies have tried unsuccessfully to test single genes to be used as prognostic markers in HNSCC. A group of tumor samples can be characterized in terms of the behavior of modules. These modules include clusters of coexpressed genes, such as genes that belong to the same pathway or functional category. Cancer is a multifaceted phenomenon that involves activation and/or disruption of various cellular processes. Thus, the identification of pathways or group of genes such as those involved in the development of lymph node metastasis and recurrent disease may help understanding the complex biology of cancer. Samples were obtained during surgery and neck dissection of 81 patients with primary untreated HNSCC at the Head and Neck Surgery Department from the Hospital AC Camargo (São Paulo, Brazil) between 1998 and 2003. Diagnosis of HNSCC was determined by biopsy. All patients signed a pre-informed consent and the study was approved by our institutional review board. After surgery, all patients were treated with adjuvant radiotherapy. Tumor samples were snap-frozen in liquid nitrogen. Before RNA extraction, diagnosis was confirmed by hematoxylin-eosin staining. Frozen samples were hand dissected for removal of normal cells, necrosis, and infiltrating inflammatory cells. Total RNA was extracted using TRIzol. RNA quality was accessed by spectrophotometry and gel electrophoresis. To be considered as high-quality, the RNA had to have a 260/280 ratio higher than 1.7 and a 18S/28S rRNA ratio ~2. Amplifictaion of the mRNA was done using a T7-based protocol and cDNA was indirectly labeled with Alexa Dye 555 or 647. Samples and a common RNA reference were hybridized overnight at 42oC in dye-swap to a 4,800-element in-house printed microarray, enriched with cancer-related ESTs derived from the Human Cancer Genome Project. After washing, slides were scanned on a confocal laser scanner and data were extracted.

ORGANISM(S): Homo sapiens

SUBMITTER: Anna Coló

PROVIDER: E-GEOD-18020 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Project description:Head and neck squamous cell carcinomas (HNSCCs) is the seventh most common solid malignancy in the United States, accounting for more than 47,000 new cancer cases. HNSCC shows significant diversity in its clinical behavior after treatment, which cannot be predicted using the current clinical or pathological markers. Despite tumor complexity, many studies have tried unsuccessfully to test single genes to be used as prognostic markers in HNSCC. A group of tumor samples can be characterized in terms of the behavior of modules. These modules include clusters of coexpressed genes, such as genes that belong to the same pathway or functional category. Cancer is a multifaceted phenomenon that involves activation and/or disruption of various cellular processes. Thus, the identification of pathways or group of genes such as those involved in the development of lymph node metastasis and recurrent disease may help understanding the complex biology of cancer. Samples were obtained during surgery and neck dissection of 47 patients with primary untreated HNSCC at the Head and Neck Surgery Department from the Hospital AC Camargo (São Paulo, Brazil) between 1998 and 2003. Diagnosis of HNSCC was determined by biopsy. All patients signed a pre-informed consent and the study was approved by our institutional review board. After surgery, all patients were treated with adjuvant radiotherapy. Recurrence were diagnosed by imaging or biopsy. Tumor samples were snap-frozen in liquid nitrogen. Before RNA extraction, diagnosis was confirmed by hematoxylin-eosin staining. Frozen samples were hand dissected for removal of normal cells, necrosis, and infiltrating inflammatory cells. Total RNA was extracted using TRIzol. RNA quality was accessed by spectrophotometry and gel electrophoresis. To be considered as high-quality, the RNA had to have a 260/280 ratio higher than 1.7 and a 18S/28S rRNA ratio ~2. Amplifictaion of the mRNA was done using a T7-based protocol and cDNA was indirectly labeled with Alexa Dye 555 or 647. Samples and a common RNA reference were hybridized overnight at 42oC in dye-swap to a 4,800-element in-house printed microarray, enriched with cancer-related ESTs derived from the Human Cancer Genome Project. After washing, slides were scanned on a confocal laser scanner and data were extracted.

Project description:Distant metastasis is a major factor associated with poor prognosis in head and neck squamous cell carcinoma (HNSCC), but little is known of its molecular mechanisms. New markers that predict clinical outcome, in particular the ability of primary tumors to develop metastatic tumors, are urgently needed. Here, we identified neurotensin, highly expressed in HNSCCs in comparison with normal tissues, as an invasion-promoting factor in HNSCC by using microarray analysis of clinical samples. Indeed, neurotensin overexpression associated with lymph node metastasis of neck, and tumors exhibiting neurotensin overexpression had a poor distant metastasis-free survival rate. In HNSCC cells which expressed neurotensin receptor 1 (NTSR1), neurotensin promoted cellular invasion, migration, and induction of matrix metalloproteinases transcripts. Disruption of NTSR1 signaling by silencing RNA caused the reversion of the invasion of HNSCC cells. By further microarray analysis using neurotensin-treated cells, neurotensin caused increased expression of genes implicated in tumor progression and metastasis including cell growth, migration, invasion, adhesion, angiogenesis, and apoptosis. Our findings have revealed a critical role of neurotensin/NTSR1 for invasion and migration in the metastatic process of HNSCC. This study raises the possibility that neurotensin/NTSR1 could be used as a possible predictive marker and a molecular therapeutic target in the antimetastatic strategies of HNSCC. Keywords: Identification of a novel therapeutic target for head and neck squamous cell carcinomas A total of 21 primary HNSCC samples were obtained from patients who underwent tumor resection at Chiba University Hospital (Chiba, Japan). 21 samples of normal-appearing mucosa at the margin of the surgical resection several centimeters from the tumor were also collected and designated histologically normal mucosa. 21 HNSCCs and paired normal tissues were used for microarray experiment. The clinicopathological grade was classified according to the criteria of the Japan Society for Head and Neck Cancer. The Ethics Committee of Chiba University approved our study, and informed consent was obtained from all patients for use of their tissue samples and clinical data. Tissue samples were immediately snap frozen in liquid nitrogen and stored at -80Â°C until use.

Project description:Purpose: Presence of pelvic lymph node metastases is the main prognostic factor in early stage cervical cancer patients, primarily treated with surgery. Aim of this study was to identify cellular tumor pathways associated with pelvic lymph node metastasis in early stage cervical cancer. Experimental Design: Gene expression profiles (Affymetrix U133 plus 2.0) of 20 patients with negative (N0) and 19 with positive lymph nodes (N+), were compared with gene sets that represent all 285 presently available pathway signatures. Validation immunostaining of tumors of 274 consecutive early stage cervical cancer patients was performed for representatives of the identified pathways. Results: Analysis of 285 pathways resulted in identification of five pathways (TGF-β, NFAT, ALK, BAD, and PAR1) that were dysregulated in the N0, and two pathways (β-catenin and Glycosphingolipid Biosynthesis Neo Lactoseries) in the N+ group. Class comparison analysis revealed that five of 149 genes that were most significantly differentially expressed between N0 and N+ tumors (P<0.001) were involved in β-catenin signaling (TCF4, CTNNAL1, CTNND1/p120, DKK3 and WNT5a). Immunohistochemical validation of two well-known cellular tumor pathways (TGF-β and β-catenin) confirmed that the TGF-β pathway (positivity of Smad4) was related to N0 (OR:0.20, 95%CI:0.06-0.66) and the β-catenin pathway (p120 positivity) to N+ (OR:1.79, 95%CI:1.05-3.05). Conclusions: Our study provides new, validated insights in the molecular mechanism of lymph node metastasis in cervical cancer. Pathway analysis of the microarray expression profile suggested that the TGF-β and p120-associated non-canonical β-catenin pathways are important in pelvic lymph node metastasis in early stage cervical cancer. For the microarray experiment, we selected fresh frozen primary cervical cancer tissue, containing at least 80% tumor cells, of patients with histologically confirmed N0 (n=20) and of patients with N+ (n=19). The N0 and N+ groups were matched for age, FIGO stage and histology (all squamous cell carcinoma).

Project description:The biology underlying nodal metastasis is poorly understood. Transcriptome profiling has helped to characterize both primary tumors seeding nodal metastasis and the metastasis themselves. The interpretation of these data, however, is not without ambiguities. Here we profiled the transcriptomes of 17 papillary thyroid cancer (PTC) nodal metastases, associated primary tumors and primary tumors from N0 patients. We also included patient-matched normal thyroid and lymph node samples as controls to address some limits of previous studies. We found that the transcriptomes of patient-matched primary tumors and metastases were more similar than of unrelated metastases/primary pairs, a result also reported in other organ systems, and that part of this similarity reflected patient background. We found that the comparison of patient-matched primary tumors and metastases was heavily confounded by the presence of lymphoid tissues in the metastasis samples. An original data adjustment procedure was developed to circumvent this problem. It revealed a differential expression of stroma-related gene expression signatures also regulated in other organ systems. The comparison of N0 vs. N+ primary tumors uncovered a signal irreproducible across independent PTC datasets. This signal was also detectable when comparing the normal thyroid tissues adjacent to N0 and N+ tumors, suggesting a cohort specific bias also likely to be present in previous studies with similar statistical power. Classification of N0 vs. N+ yielded an accuracy of 63%, but additional statistical controls not presented in previous studies, revealed that this is likely to occur by chance alone. To address this issue, we used large datasets from The Cancer Genome Atlas and showed that N0 vs. N+ classification rates could not be reached randomly for most cancers. Yet, it was significant, but of limited accuracy (<70%) for thyroid, breast and head and neck cancers. We profiled the transcriptomes of 11 primary PTCs with no detectable nodal invasion, 17 primary PTCs with nodal invasion and 17 patient-matched nodal metastases. We also profiled a number of control samples. These included 24 patient-matched normal thyroid tissues (11 from N0, 13 from N+ patients), and 4 normal lymph nodes; technical and biological replicates including additional nodal metastasis for 3 patients, adjacent blocks for 5 primary tumors, 4 normal thyroid tissues and 1 nodal metastasis.

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Gene expression profile of N+ and N0 HNSCC

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