Cardiac and kidney hormones cure up to 86% of human small-cell lung cancers in mice.

BACKGROUND: Four cardiac hormones synthesized by the same gene, i.e. atrial natriuretic peptide, vessel dilator, long acting natriuretic peptide and kaliuretic peptide, and the kidney hormone urodilatin have anticancer effects in vitro. MATERIALS AND METHODS: These cardiac hormones and urodilatin were infused subcutaneously for 28 days with weekly fresh hormones since they lose biological effects at body temperature for more than a week at 0.3 nm kg(-1) body weight in athymic mice bearing human small-cell lung carcinomas. RESULTS: Long acting natriuretic peptide, vessel dilator, kaliuretic peptide, atrial natriuretic peptide and urodilatin eliminated 86%, 71%, 57%, 43% (P < 0.001 for the cardiac hormones) and 25% (P < 0.05; urodilatin) of the human small-cell lung carcinomas. The treated small-cell lung carcinomas that were not cured grew rapidly, similar to the untreated controls, whose volume was 7 fold larger in 1 week, 18-fold increased in 2 weeks, 39-fold increased in 3 weeks, 63-fold increased in 1 month and 97-fold increased in volume in 6 weeks. One vessel dilator treated small-cell lung carcinoma animal developed a large tumour (8428 mm3 volume) on treatment and this tumour was eliminated with utilizing atrial natriuretic peptide and then long acting natriuretic peptide sequentially. CONCLUSIONS: Four cardiac hormones eliminate up to 86% of human small-cell lung carcinomas in athymic mice. Urodilatin can also eliminate small-cell lung carcinomas but at a lower cure rate of 25%. Unresponsive lesions can be eliminated by utilizing different hormones synthesized by the atrial natriuretic peptide gene in a sequential manner.

Urodilatin and four cardiac hormones decrease human renal carcinoma cell numbers.

BACKGROUND: Mortality from renal-cell cancer remains a significant problem with an estimated 12,600 deaths in the United States in 2005 even with current treatment(s) of surgery, chemotherapy, radiation and immunotherapy. Four cardiac natriuretic peptides, that is, atrial natriuretic peptide, vessel dilator, long-acting natriuretic peptide and kaliuretic peptide have significant anti-cancer effects in breast, pancreatic, prostate and colon adenocarcinomas. MATERIALS AND METHODS: These four peptide hormones plus brain natriuretic peptide (BNP), C-natriuretic peptide (CNP) and urodilatin, a peptide hormone formed in the kidney by a different post-translational processing of the atrial natriuretic peptide prohormone, were evaluated for their anti-cancer effects in renal carcinomas. RESULTS: Dose-response curves revealed a significant (P < 0.0001) decrease in human renal carcinoma cells with each 10-fold increase in concentration from 1 microm to 100 microm of five of these peptide hormones. There was an 81%, 74%, 66%, 70% and 70% elimination within 24 h in renal carcinoma cells secondary to vessel dilator, kaliuretic peptide, urodilatin, atrial natriuretic peptide and long-acting natriuretic peptide, respectively (P < 0.0001 for each), whereas BNP had no effect and CNP decreased renal cancer cell number by 10% (P = 0.04) at their 100 microm concentrations. Three days after treatment with these peptide hormones, the cancer cells began to proliferate again. The four cardiac hormones and urodilatin decreased DNA synthesis from 65-84% (P < 0.00001), whereas BNP and CNP decreased DNA synthesis 3% and 12% (both non-significant). Western blots revealed for the first time natriuretic peptide receptors (NPR)-A, -B and -C were present in the renal cancer cells. CONCLUSIONS: These results indicate that urodilatin and the four cardiac hormones have potent anti-cancer effects by eliminating up to 81% of renal carcinoma cells within 24 h of treatment.

Four peptide hormones' specific decrease (up to 97%) of human prostate carcinoma cells.

BACKGROUND: Mortality from prostate cancer remains a significant problem with current treatment(s), with an expected 30 350 deaths from prostate cancer in 2005. Long-acting natriuretic peptide, vessel dilator, kaliuretic peptide and atrial natriuretic peptide have significant anticancer effects in breast and pancreatic adenocarcinomas. Whether these effects are specific and whether they have anticancer effects in prostate adenocarcinoma cells has not been determined. MATERIALS AND METHODS: These peptide hormones were evaluated to determine if they have specific anticancer effects in human prostate adenocarcinomas. RESULTS: Dose-response curves revealed a significant (P < 0.05) decrease in human prostate cancer number with each tenfold increase in the concentration from 1 microM to 1000 microM (i.e. 1 mM) of these four peptide hormones. There was a 97.4%, 87%, 88% and 89% (P < 0.001 for each) decrease in prostate cancer cells secondary to vessel dilator, long-acting natriuretic peptide, kaliuretic peptide and atrial natriuretic peptide, respectively, at their 1-mM concentrations within 24 h, without any proliferation in the 3 days following this decrease. These same hormones decreased DNA synthesis from 68% to 89% (P < 0.001). When utilized with their respective antibodies their ability to decrease prostate adenocarcinoma cells or inhibit their DNA synthesis was completely blocked. Western blots revealed that for the first time natriuretic peptide receptors (NPR) A- and C- were present in prostate cancer cells. CONCLUSIONS: These results indicate that these peptide hormones' anticancer effects are specific. Furthermore, they have very potent effects of eliminating up to 97% of prostate cancer cells within 24 h of treatment.

Five cardiac hormones decrease the number of human small-cell lung cancer cells.

BACKGROUND: Four peptide hormones of a family of six hormones, i.e. atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), C-natriuretic peptide (CNP), long acting natriuretic peptide (LANP), vessel dilator and kaliuretic peptide, significantly decrease the number of adenocarcinoma cells in culture. The present investigation was designed to determine whether these peptide hormones' effects are specific to adenocarcinomas or whether they might decrease the number of cancer cells of a different type of cancer, i.e. small-cell lung cancer. METHODS AND MATERIALS: These six hormones were evaluated for their ability to decrease the number and/or proliferation of human small-cell lung cancer cells in culture for 24, 48, 72, and 96 h. RESULTS: Within 24 h, vessel dilator, LANP, kaliuretic peptide, ANP and their intracellular mediator cyclic GMP, each at 1 microM, decreased the number of small-cell lung cancer cells by 63% (P < 0.001), 21% (P < 0.05), 30% (P < 0.05), 39% (P < 0.05), and 31% (P < 0.05), respectively. There was no proliferation in the 3 days following this decrease in cell number. These same hormones decreased DNA synthesis 68% to 82% (P < 0.001). Brain natriuretic peptide and CNP did not decrease the number of small-cell lung cancer cells or inhibit their DNA synthesis at 1 microM or 10 microM concentrations. Dose-response curves revealed that at 100 microM, the vessel dilator decreased 92% of the cancer cells in 24 h while BNP had no effect, but CNP caused a 39% decrease. Western blots revealed that the natriuretic peptide receptors A- and C- were present in these cancer cells. CONCLUSIONS: Five peptide hormones significantly decrease the number of human small-cell lung cancer cells within 24 h and inhibit their proliferation for at least 96 h. Their mechanism of doing so involves inhibition of DNA synthesis mediated in part by cyclic GMP.