Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Malignant melanoma is a neuroendocrine tumor that contains somatostatin receptors (SSTRs). Adjuvant therapy for melanoma is limited. Because melanomas arise from neural crest cells, we sought to evaluate the distribution of SSTR subtypes found in these tumors and their functional significance by imaging with 111In-pentetreotide scintigraphy (OctreoScan). Octreotide binds with greatest affinity to SSTR2 and SSTR5. Studying the expression of SSTRs in melanoma may demonstrate a potential role for octreotide in the treatment of melanoma. A series of 23 melanomas from 17 patients who underwent resection of regional or distant metastases were evaluated for the presence of SSTRs by the reverse transcriptase-polymerase chain reaction (RT-PCR) using primers specific for SSTR1 through SSTR5. Identity of RT-PCR products was confirmed by Southern blot analysis. Sixteen patients underwent preoperative OctreoScan. SSTR1 was expressed in 96% of tumors, SSTR2 in 83%, SSTR3 in 61%, SSTR4 in 57%, and SSTR5 in 9%. OctreoScan imaged 63% of tumors. There was no correlation between SSTR subtype expression and OctreoScan result. Most of the melanomas expressed mRNA for SSTR1 and SSTR2, with approximately half expressing SSTR3 and SSTR4. The SSTR mRNA for SSTR2 appears to be transcribed into functional protein that binds 111In-pentetreotide in more than half of these patients. Although OctreoScan has limited sensitivity for localizing melanomas, tumors that can be imaged by OctreoScan may be amenable to adjuvant therapy with octreotide or targeted therapy with high-energy radioisotope-labeled octreotide. These studies clearly define melanoma as a neuroendocrine tumor, which may open new avenues for tumor control.
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PMID:Distribution and functional significance of somatostatin receptors in malignant melanoma. 1134 89

Neuroendocrine tumors in the lung fall into four categories: typical carcinoid tumor (TC), atypical carcinoid tumor (AC), large-cell neuroendocrine carcinoma (LCNEC) and small-cell lung carcinoma (SCLC), in ascending order of malignancy. The drs gene was originally isolated as a suppressor against v-src transformation and was shown to induce apoptosis in human cancer cells. The expression of drs was markedly downregulated in various human cancer tissues and cell lines. Furthermore, drs knockout mice showed a tumor-prone phenotype, indicating that drs acts as a tumor suppressor gene in malignant tumor formation. To clarify the role of the drs gene in the development of human pulmonary neuroendocrine tumors, we examined the expression of drs mRNA in tissue specimens from 3 cases of TC, 4 cases of AC, 2 cases of LCNEC, and 11 cases of SCLC by in situ mRNA hybridization. Four cases of normal lung and bronchial epithelia, 8 samples of normal brain tissue, and 2 cases of tumorlets in the lung were also examined. The drs mRNA was definitely expressed in all normal tissues of the lung and brain, and 3 TC and 2 tumorlet tissues. The expression of drs mRNA was also detected in 2 of 2 LCNEC tissues and 3 of 4 AC tissues, although the signals were weak. On the other hand, drs mRNA was not detected in 10 of 11 SCLC tissues. Downregulation of drs mRNA was also observed in 3 of 4 SCLC cell lines that were examined by reverse transcriptase-polymerase chain reaction (RT-PCR). Neither gross deletion nor rearrangement of the drs genome was detected in these cell lines by Southern blot analysis. Our results indicate that the downregulation of drs is correlated with the development of SCLC, a highly malignant pulmonary neuroendocrine tumor.
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PMID:Downregulation of drs tumor suppressor gene in highly malignant human pulmonary neuroendocrine tumors. 1942 11

Patient was a 55-year-old man with history of pancreas neuroendocrine tumor grade 2, Ki-67 index 10%. He was treated with surgical resection. Ga-DOTANOC PET/CT was performed as part of follow-up of known disease. The images showed opacities in both lungs' parenchyma with moderate uptake of radiotracer and mediastinal lymph nodes with high uptake suggestive of infection. Two weeks before a high-resolution CT was performed, these findings in the lungs were not present. The patient was asymptomatic and was referred to the emergency department for reverse transcriptase-polymerase chain reaction COVID-19 test, and the result was positive.
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PMID:68Ga-DOTANOC PET/CT With Lung Involvement in the Era of COVID-19 Pandemic. 3323 42