Project description:A classifier was build on 82 training samples to differentiate between lymph node negative (N0) and lymph node metastasis (N+) head and neck squamous-cell carcinomas (HNSCC). The 102 predictor genes that resulted from this classifier where then validated against a independent validation set.
Project description:An experiment was performed to investigate the perservation of gene expression upon metastasis of primary head and neck squamous cell carcinomas to the cervical lymph node.
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. 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.
Project description:MicroRNA expression in two pair of head and neck squamous cell carcinoma cell lines were analyzed. 4A/4B and 37A/37B cells were from two different head and neck squamous cell carcinoma patients. A cells were from patients' primary focus. B cells were from patients' lymph node metastasis. B cells have higher migratory and invasive abilities and CCR7 expression levels than A cell.
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. 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.
Project description:Metabolic flexibility is a common hallmark of aggressive and metastatic cancers. Here, we reveal that dynamic changes in mitochondrial translation rates drive the switch between glycolytic and mitochondrial energy production required for metastasis. We find that loss of 5-methylcytosine (m5C) in mitochondrial tRNAMet is sufficient to repress mitochondrial translation and trigger the switch from oxidative phosphorylation (OXPHOS) to glycolysis. Glycolytic tumour cells form primary tumours but fail to metastasize in an orthotopic mouse model of human oral cancer. Instead, a small subpopulation of non-dividing tumour cells requires high OXPHOS levels for invasion and metastasis. Although this metastasis-initiating metabolic switch is highly dynamic and reversible, we identify a mitochondria-driven gene signature predictive for lymph node metastasis and disease progression. Finally, we demonstrate that pharmacological inhibition of mitochondrial translation blocks metastasis in orthotopic transplants. Together, our results indicate that metastasis-initiating cells can be eradicated by blocking mitochondrial translation.
Project description:Background: Cervical lymph node metastasis is a potent prognostic factor in oral squamous cell carcinoma (OSCC). However, lymph nodes resected by sentinel node biopsy or neck dissection are usually diagnosed by examining only one or two sections of the maximal cut surface. Accurate diagnosis of the metastasis in lymph nodes is important but depends on a heavy workload of the pathologist. In this study, we have attempted to identify novel molecular markers to find the harboring cancer cells in the lymph node and establish rapid detection method. Methods: We determined the gene expression profiles of 7 metastatic lymph nodes from patients with OSCC and 1 normal lymph node and 5 salivary glands from non-cancerous patients by microarray analysis. We found the overexpression genes in all metastatic lymph nodes. Subsequently, we examined the expression of these genes in newly 23 metastatic lymph nodes and 9 normal lymph nodes by real-time quantitative RT-PCR (qRT-PCR) assay. Moreover, the rapid detection of lymph node metastasis by these genes was examined using the reverse transcription loop-mediated isothermal amplification (RT-LAMP) method. Result: Among the 4 genes identified by microarray analysis, annexin A8 (ANXA8) and desmoglein 3 (DSG3) were detected in all metastatic lymph nodes at a much higher level but not in normal lymph nodes at all by qRT-PCR. Furthermore, RT-LAMP method targeting ANXA8 rapidly detected almost lymph nodes with metastasis. Conclusions: ANXA8 could be a useful marker for detecting lymph node metastasis in OSCC. Using AB1700 system, we determined the gene expression profiles of lymph nodes with metastasis of OSCC. Normal lymph node and salivary gland tissues were used as control samples.
Project description:Several studies have demonstrated that melanoma-derived exosomes home in sentinel lymph nodes favoring metastasis. Here, we determined the proteomic signature in exosomes derived from lymph node metastatic models. We found a signature of genes over-expressed and proteins hyper-secreted in exosomes related to lymph node metastasis in the B16 mouse melanoma model. Out of these candidates, we found that Emilin1, a protein with an important function in lymph node physiology, was hyper-secreted in exosomes. Interestingly, we found that Emilin1 is degraded and secreted in exosomes as a mechanism favoring metastasis. Indeed, we found that Emilin1 has a tumor suppressor-like role regulating negatively cell viability and migration. Importantly, our in vivo studies demonstrate that Emilin1 overexpression reduced primary tumor growth and metastasis in mouse melanoma models. Analysis in human melanoma samples showed that cells expressing high levels of EMILIN1 are reduced in metastatic lesions. Overall, our analysis suggests a novel mechanism involved in the inactivation of Emilin1 in melanoma favouring melanoma progression and metastasis.
Project description:Using a mouse model of breast cancer that develops spontaneous lymph node metastasis, we performed high-resolution single-cell RNA sequencing (scRNA-Seq) of the primary tumor and TDLN to measure how cancer cells adapt to the dynamic lymph node microenvironment. To understand the dynamic change of lymph node microenvironment after cancer cell invasion, we also compared the gene-expression alteration between naive lymph node and TDLN at single-cell level.