pituitrin and Carcinoma--Non-Small-Cell-Lung

It is proposed that neuropeptide production by tumours is an important part of a special process of oncogenic transformation rather than a pre-existing condition of progenitor cells; this concept is called Selective Tumour gene Expression of Peptides essential for Survival (STEPS). All small-cell lung cancers and breast cancers evidently express the vasopressin gene, and this gene seems to be structurally normal in all but exceptional cases. Vasopressin gene expression in cancer cells leads to the production of both normal and abnormal forms of tumour vasopressin mRNA and proteins. Although the necessary post-translational processing enzymes are expressed in these cells, most processing seems to be extragranular, and most of the protein products become components of the plasma membrane. Small-cell lung cancer and breast cancer cells also express normal genes for all vasopressin receptors and produce normal vasopressin receptor mRNAs and V1a and V1b receptor proteins, and the vasopressin-activated calcium mobilising (VACM) protein; plus both normal and abnormal forms of the V2 receptor. Through these receptors, vasopressin exercises multifaceted effects on tumour growth and metabolism. A normal protein vasopressin gene promoter seems to be present in small-cell lung cancer cells, and this promoter contains all of the transcriptional elements known to be involved in gene regulation within hypothalamic neurones. Since these elements largely account for regulation of tumour gene expression observed in vitro, it is likely that as yet unknown factors are selectively produced by tumours in vivo to account for the observed seemingly autonomous or unregulated production of hormone in tumour patients. Promoter elements thought to be responsible for selective vasopressin gene expression in small-cell lung cancer probably include an E-box and a neurone restrictive silencer element close to the transcription start site. It is possible that transcription factors acting at these same elements can explain selective vasopressin expression, not only in small-cell tumours, but also in all other tumours such as breast cancer. By extrapolation, similar mechanisms might also be responsible for the expression of additional features that characterize the 'neuroendocrine' profile of these cancers.

Topics: Animals; Breast Neoplasms; Carcinoma, Non-Small-Cell Lung; Carcinoma, Small Cell; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; Receptors, Vasopressin; Vasopressins

Topics: Acrylamides; Aged; Aniline Compounds; Carcinoma, Non-Small-Cell Lung; Drug Substitution; Female; Humans; Inappropriate ADH Syndrome; Treatment Outcome; Vasopressins

Topics: Biopsy, Needle; Carcinoma, Non-Small-Cell Lung; Humans; Inappropriate ADH Syndrome; Lung Neoplasms; Vasopressins

The 99mTc-labeled conjugates of the vasopressin (AVP) peptide and of its analogue d(CH2)5[D-Tyr(Et2)-Ile4-Eda9]AVP (AVP(an)) have been synthesized using the technetium complexes with tetradentate tripodal chelator (the tris(2-mercaptoethyl)amine (NS3)) and the monodentate isocyanide ligand (CN-peptide). The conjugates exhibit high stability in the presence of 100 times the molar excess of standard amino acids cysteine or histidine and also satisfactory stability in human serum. The 99mTc(NS3)(CN-AVP) and 99mTc(NS3)(CN-AVP(an)) ability of binding to small-cell lung cancer (SCLC) cell line H69 was studied in vitro. The results suggest that the novel vasopressin conjugate 99mTc(NS3)(CN-AVP(an)) is a desirable compound for imaging oncogene receptors overexpressed in SCLC cells and can be an important basis for further consideration the conjugate as a potential diagnostic radiopharmaceutical for patients suffering from small-cell lung cancer.

Topics: Animals; Carcinoma, Non-Small-Cell Lung; Humans; Lung Neoplasms; Molecular Conformation; Oligopeptides; Organometallic Compounds; Radiopharmaceuticals; Rats; Rhenium; Technetium; Tumor Cells, Cultured; Vasopressins

A 60-year-old female underwent right upper lobectomy of the lung and lymph node dissection under a diagnosis of cancer in the upper lobe of the right lung. Pathological examination showed stage IIIA adenocarcinoma with mediastinal lymph node metastasis. One month after the operation, adjuvant chemotherapy with carboplatin (CBDCA) and paclitaxel (PTX) was initiated. Four days after the chemotherapy, hyponatremia progressed, and central nervous system disorder developed. A diagnosis of syndrome of inappropriate secretion of antidiuretic hormone (SIADH) was made. She recovered after fluid intake restriction and electrolyte correction. SIADH was considered to be due to the adverse effects of anticancer drugs. In postoperative adjuvant chemotherapy, attention should be paid to the serum Na level.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Animals; Antineoplastic Agents; Antineoplastic Agents, Phytogenic; Antineoplastic Combined Chemotherapy Protocols; Carboplatin; Carcinoma, Non-Small-Cell Lung; Combined Modality Therapy; Female; Humans; Hyponatremia; Inappropriate ADH Syndrome; Lung; Lung Neoplasms; Lymphatic Metastasis; Middle Aged; Paclitaxel; Vasopressins