Skip to main content
Log in

Involvement of phosphoinositide-3-kinase and p70 S6 kinase in regulation of proliferation of rat lactotrophs in culture

  • Published:
Endocrine Aims and scope Submit manuscript

Abstract

Phosphoinositide-3-kinase (PI-3K) and p70 S6 kinase (p7056k) are suggested as important molecules for mediating mitogenic actions of growth factors and cytokines in variety of cell types. The purpose of the present study was to investigate whether these kinases were involved in mediation of the mitogenic actions of not only the growth factor insulin but also cyclic adenosine monophosphate (cAMP) and estrogen on rat cultured lactotrophs. Treatment with wortmannin or LY294002, a PI-3K inhibtor, or rapamycin, a p70S6k inhibitor, decreased basal levels of 5-bromo-2-deoxyuridine (BrdU)-labeling indices of lactotrophs in a dose-dependent manner. These inhibitors were effective in blocking an increase in BrdU-labeling indices induced by insulin. LY294002 and rapamycin also suppressed an increase in BrdU-labeling indices induced by forskolin, an adenylate cyclase activator, or dibutyryl cAMP, a membrane-permeable cAMP analog, as well as that induced by estradiol, a physiologic extracellular activator of lactotroph proliferation. However, the dibutyryl cAMP-, but not insulin-induced proliferation, acquired a resistance to LY294002 and rapamycin by pretreatment with bromocriptine, a dopaminergic agonist that is able to suppress lactotroph proliferation. These results suggest that the mitogenic actions of cAMP and estradiol on rat lactotrophs are mediated by PI-3K and p70S6k, and that dopaminergic inhibition modifies the PI-3K and p70S6k dependence of the regulation of lactotroph proliferation.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Wiklund, J., Wertz, N., and Gorski, J. (1981). Endocrinology 109, 1700–1707.

    PubMed  CAS  Google Scholar 

  2. Lieberman, M. E., Maurer, R. A., Claude, P., and Gorski, J. (1982). Mol. Cell. Endocrinol. 25, 277–294.

    Article  PubMed  CAS  Google Scholar 

  3. Sarkar, D. K., Gottschall, P. E., and Meites, J. (1982). Science 218, 684–686.

    Article  PubMed  CAS  Google Scholar 

  4. Song, J., Jin, L., and Lloyd, R. V. (1989). Cancer Res. 49, 1247–1253.

    PubMed  CAS  Google Scholar 

  5. Arita, J., Kojima, Y., and Kimura, F. (1990). Neuroendocrinology 52, 249–255.

    PubMed  CAS  Google Scholar 

  6. Ben-Jonathan, N. (1985). Endocr. Rev. 6, 564–589.

    PubMed  CAS  Google Scholar 

  7. MacLeod, R. M. and Lehmeyer, J. E. (1973). Cancer Res. 33, 849–855.

    PubMed  CAS  Google Scholar 

  8. Lloyd, H. M., Meares, J. D., and Jacobi, J. (1975). Nature 255, 497–498.

    Article  PubMed  CAS  Google Scholar 

  9. Melmed, S. (1981). Endocrinology 109, 2258–2260.

    PubMed  CAS  Google Scholar 

  10. Arita, J., Hashi, A., Hoshi, K., Mazawa, S., and Suzuki, S. (1998). Neuroendocrinology 68, 163–171.

    Article  PubMed  CAS  Google Scholar 

  11. Bevan, J. S., Webster, J., Burke, C. W., and Scanlon, M. F. (1992). Endocr. Rev. 13, 220–240.

    Article  PubMed  CAS  Google Scholar 

  12. Ray, D., and Melmed, S. (1997). Endocr. Rev. 18, 206–228.

    Article  PubMed  CAS  Google Scholar 

  13. Suzuki, S., Yamamoto, I., and Arita, J. (1999). Endocrinology 140, 2850–2858.

    Article  PubMed  CAS  Google Scholar 

  14. Carpenter, C. L. and Cantley, L. C. (1996). Biochim. Biophys. Acta. 1288, M11-M16.

    PubMed  Google Scholar 

  15. Karnitz, L. M., Burns, L. A., Sutor, S. L., Blenis, J., and Abraham, R. T. (1995). Mol. Cell. Biol. 15, 3049–3057.

    PubMed  CAS  Google Scholar 

  16. Roche, S., Koegl,M., and Courtneidge, S. A. (1994). Proc. Natl. Acad. Sci. USA 91, 9185–9189.

    Article  PubMed  CAS  Google Scholar 

  17. Valius, M. and Kazlauskas, A. (1993). Cell. 73, 321–334.

    Article  PubMed  CAS  Google Scholar 

  18. Vlahos, C. J., Matter, W. F., Hui, K. Y., and Brown, R. F. (1994). J. Biol. Chem. 269, 5241–5248.

    PubMed  CAS  Google Scholar 

  19. Chou, M. M. and Blenis, J. (1995). Curr. Opin. Cell Biol. 7, 806–814.

    Article  PubMed  CAS  Google Scholar 

  20. Kuo, C. J., Chung, J., Fiorentino, D. F., Flanagan, W. M., Blenis, J., and Crabtree, G. R. (1992). Nature 358, 70–73.

    Article  PubMed  CAS  Google Scholar 

  21. Lane, H. A., Fernandez, A., Lamb, N. J. C., and Thomas, G. (1993). Nature 363, 170–172.

    Article  PubMed  CAS  Google Scholar 

  22. Price, D. J., Grove, J. R., Calvo, V., Avruch, J., and Biere, B. E. (1992). Science 257, 973–977.

    Article  PubMed  CAS  Google Scholar 

  23. Chung, J., Grammer, T. C., Lemon, K. P., Kazlauskas, A., and Blenis, J. (1994). Nature 370, 71–75.

    Article  PubMed  CAS  Google Scholar 

  24. Ui, M., Okada, T., Hazeki, K., and Hazeki, O. (1995). Trends Biochem. Sci. 20, 303–307.

    Article  PubMed  CAS  Google Scholar 

  25. Yano, H., Nakanishi, S., Kimura, K., Hanai, N., Saitoh, Y., Fukui, Y., Nonomura, Y., and Matsuda, Y. (1993). J. Biol. Chem. 268, 25,846–26,856.

    CAS  Google Scholar 

  26. Bonser, R. W., Thompson, N. T., Randall, R. W., Tateson, J. E., Spacey, G. D., Hodson, H. F., and Garland, L. G. (1991). Br. J. Pharmacol. 103, 1237–1241

    PubMed  CAS  Google Scholar 

  27. Hunter, T. (1995). Cell 83, 1–4.

    Article  PubMed  CAS  Google Scholar 

  28. Brown, E. J., Beal, P. A. Keith, C. T., Chen, J., Shin, T. B., and Schreiber, S. L. (1995). Nature 377, 441–446.

    Article  PubMed  CAS  Google Scholar 

  29. Cass, L. A. and Meinkoth, J. L. (1998). Endorinology 139, 1991–1998.

    Article  CAS  Google Scholar 

  30. Monfar, M., Lemon, K. P., Grammer, T. C., Cheatham, L., Chung, J., Vlahos, C. J., and Blenis, J. (1995). Mol. Cell. Biol. 15, 326–337.

    PubMed  CAS  Google Scholar 

  31. Kimura, K., Hattori, S., Kabuyama, Y., Shizawa, Y., Takayanagi, J., Nakamura, S., Toki, S., Matsuda, Y., Onodera, K., and Fukui, Y. (1994). J. Biol. Chem. 269, 18,961–18,967.

    CAS  Google Scholar 

  32. Sara, V. R. and Hall, K. (1990). Physiol. Rev. 70, 591–614.

    PubMed  CAS  Google Scholar 

  33. Bach, M. A. and Bondy, C. A. (1992). Endocrinology 131, 2588–2594.

    Article  PubMed  CAS  Google Scholar 

  34. Geary, E. S., Lim, M., Ceda, G. P., Ro, S., Rosenfeld, R. G., and Hoffman, A. R. (1989). J. Neuroendocrinol. 1, 179–184.

    Article  CAS  PubMed  Google Scholar 

  35. Roger, P. P., Reuse, S., Maenhaut, C., and Dumont, J. E. (1995). Vitam. Horm. 51, 59–191.

    Article  PubMed  CAS  Google Scholar 

  36. Withers, D. J., Bloom, S. R., and Rozengurt, E. (1995). J. Biol. Chem. 270, 21,411–21,419.

    CAS  Google Scholar 

  37. Cook, S. J. and McComick, F. (1993). Science 262, 1069–1072.

    Article  PubMed  CAS  Google Scholar 

  38. Wu, J., Dent, P., Jelinek, T., Wolfman, A., Weber, M. J., and Sturgill, T. W. (1993). Science 262, 1065–1069.

    Article  PubMed  CAS  Google Scholar 

  39. Miller, M. J., Prigent, S., Kupperman, E., Rioux, L., Park, S.-H., Feramisco, J. R., White, M. A., Rutkowski, J. L., and Meinkoth, J. L. (1997). J. Biol. Chem. 272, 5600–5605.

    Article  PubMed  CAS  Google Scholar 

  40. Duckworth, B. C. and Cantley, L. C. (1997). J. Biol. Chem. 272, 27,665–27,670.

    Article  CAS  Google Scholar 

  41. Lopez-Ilasaca, M., Crespo, P., Pellici, P. G., Gutkind, J. S., and Wetzker, R. (1997). Science 275, 394–397.

    Article  PubMed  CAS  Google Scholar 

  42. Mukhopadhyay, N. K., Price, D. J., Kyriakis, J. M., Pelech, S., Sanghera, J., and Avruch, J. (1992). J. Biol. Chem. 267, 3325–3335.

    PubMed  CAS  Google Scholar 

  43. Dickson, R. B., and Lippman, M. E. (1995). Endocr. Rev. 16, 559–589.

    Article  PubMed  CAS  Google Scholar 

  44. Watson, P. H., Pon, R. T., and Shiu, R. P. C. (1991). Cancer Res. 51, 3996–4000.

    PubMed  CAS  Google Scholar 

  45. Webb, D. K., Moulton, B. C., and Khan, S. A. (1990). Biochem. Biophys. Res. Commun. 168, 721–726.

    Article  PubMed  CAS  Google Scholar 

  46. Weisz, A. and Bresciani, F. (1988). Mol. Endocrinol. 2, 816–824.

    Article  PubMed  CAS  Google Scholar 

  47. Canicio, J., Gallardo, E., Illa, I., Testar, X., Palacín, M., Zorzano, A., and Kaliman, P. (1998). Endocrinology 139, 5042–5049.

    Article  PubMed  CAS  Google Scholar 

  48. Neill, J. D., Smith, P. F., Luque, E. H., de Toro, M. M., Nagy, G., and Mulchahey, J. J. (1987). Recent Prog. Horm. Res. 43, 175–229.

    PubMed  CAS  Google Scholar 

  49. Ramírez, J. L., Castaño, J. P., Torronteras, R., Martínez-Fuentes, A. J., Frawley, L. S., Gacía-Navarro, S., and Gracia-Navarro, F. (1999). Endocrinology 140, 1752–1759.

    Article  PubMed  Google Scholar 

  50. Denef, C., Baes, M., and Schramme, C. (1984) Endocrinology 114, 1371–1378.

    Article  PubMed  CAS  Google Scholar 

  51. Hashi, A., Mazawa, S., Kato, J., and Arita, J. (1995), Endocrinology 136, 4665–4671.

    Article  PubMed  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Jun Arita.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Kawashima, K., Yamakawa, K. & Arita, J. Involvement of phosphoinositide-3-kinase and p70 S6 kinase in regulation of proliferation of rat lactotrophs in culture. Endocr 13, 385–392 (2000). https://doi.org/10.1385/ENDO:13:3:385

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1385/ENDO:13:3:385

Key words

Navigation