Pregnancy Inhibits Mammary Carcinogenesis by Persistently Altering the Hypothalamic–Pituitary Axis
Early full-term pregnancy is known to reduce the lifetime risk of breast cancer. Although the phenomenon of parity-induced protection is well-established, the physiological mechanisms involved in this protection are not clear. Earlier reports have shown that pregnancy results in alterations of hormo...
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| Format: | Article |
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MDPI AG
2021-06-01
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| Series: | Cancers |
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| Online Access: | https://www.mdpi.com/2072-6694/13/13/3207 |
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| author | Ramadevi Subramani Adriana Estrada Madeline Dixon Maria Parada Sheryl Rodriguez Diego A. Pedroza Matthew D. Ramirez Alexa Clift Lilia Garcia Rajkumar Lakshmanaswamy |
| author_facet | Ramadevi Subramani Adriana Estrada Madeline Dixon Maria Parada Sheryl Rodriguez Diego A. Pedroza Matthew D. Ramirez Alexa Clift Lilia Garcia Rajkumar Lakshmanaswamy |
| author_sort | Ramadevi Subramani |
| collection | DOAJ |
| description | Early full-term pregnancy is known to reduce the lifetime risk of breast cancer. Although the phenomenon of parity-induced protection is well-established, the physiological mechanisms involved in this protection are not clear. Earlier reports have shown that pregnancy results in alterations of hormone levels. How pregnancy affects hypothalamic hormones and how the change, if any, influences breast cancer is not well understood. Seven-week-old female Lewis rats were given N-methyl-N-nitrosourea. Two weeks post carcinogen exposure, a set of females were housed with males to generate the parous rats and another set of rats served as the nulliparous controls. Mammary tumorigenesis was assessed for 9 months. Hypothalamic and pituitary levels of hormones were measured at various timepoints. Further, animals were also challenged with growth hormone and prolactin secretagogues to test the effect of pregnancy on the hypothalamic–pituitary hormonal axis. Persistent alterations in the level of growth hormone-releasing hormone, thyrotropin releasing hormone, dopamine, and somatostatin in the hypothalamus of parous animals was observed. Further, we also observed that pregnancy had a significant effect on the pituitary gland and its response to growth hormone and prolactin secretagogues. Our studies using the rodent model system demonstrate that pregnancy could be reducing the risk of breast cancer by persistently altering the hypothalamic–pituitary axis, which could have implications for breast cancers in humans as well. |
| first_indexed | 2024-03-10T10:01:44Z |
| format | Article |
| id | doaj.art-89d1f20fc958445b9a787a9b7be8ac43 |
| institution | Directory Open Access Journal |
| issn | 2072-6694 |
| language | English |
| last_indexed | 2024-03-10T10:01:44Z |
| publishDate | 2021-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Cancers |
| spelling | doaj.art-89d1f20fc958445b9a787a9b7be8ac432023-11-22T01:54:55ZengMDPI AGCancers2072-66942021-06-011313320710.3390/cancers13133207Pregnancy Inhibits Mammary Carcinogenesis by Persistently Altering the Hypothalamic–Pituitary AxisRamadevi Subramani0Adriana Estrada1Madeline Dixon2Maria Parada3Sheryl Rodriguez4Diego A. Pedroza5Matthew D. Ramirez6Alexa Clift7Lilia Garcia8Rajkumar Lakshmanaswamy9Center of Emphasis in Cancer, Department of Molecular and Translational Medicine, Paul L Foster School of Medicine, Texas Tech University Health Sciences Center El Paso, El Paso, TX 79905, USADepartment of Cell Biology & Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USAPaul L Foster School of Medicine, Texas Tech University Health Sciences Center El Paso, El Paso, TX 79905 USAGraduate School of Biomedical Sciences, Texas Tech University Health Sciences Center El Paso, El Paso, TX 79905, USACenter of Emphasis in Cancer, Department of Molecular and Translational Medicine, Paul L Foster School of Medicine, Texas Tech University Health Sciences Center El Paso, El Paso, TX 79905, USAGraduate School of Biomedical Sciences, Texas Tech University Health Sciences Center El Paso, El Paso, TX 79905, USAPaul L Foster School of Medicine, Texas Tech University Health Sciences Center El Paso, El Paso, TX 79905 USAGraduate School of Biomedical Sciences, Texas Tech University Health Sciences Center El Paso, El Paso, TX 79905, USAGraduate School of Biomedical Sciences, Texas Tech University Health Sciences Center El Paso, El Paso, TX 79905, USACenter of Emphasis in Cancer, Department of Molecular and Translational Medicine, Paul L Foster School of Medicine, Texas Tech University Health Sciences Center El Paso, El Paso, TX 79905, USAEarly full-term pregnancy is known to reduce the lifetime risk of breast cancer. Although the phenomenon of parity-induced protection is well-established, the physiological mechanisms involved in this protection are not clear. Earlier reports have shown that pregnancy results in alterations of hormone levels. How pregnancy affects hypothalamic hormones and how the change, if any, influences breast cancer is not well understood. Seven-week-old female Lewis rats were given N-methyl-N-nitrosourea. Two weeks post carcinogen exposure, a set of females were housed with males to generate the parous rats and another set of rats served as the nulliparous controls. Mammary tumorigenesis was assessed for 9 months. Hypothalamic and pituitary levels of hormones were measured at various timepoints. Further, animals were also challenged with growth hormone and prolactin secretagogues to test the effect of pregnancy on the hypothalamic–pituitary hormonal axis. Persistent alterations in the level of growth hormone-releasing hormone, thyrotropin releasing hormone, dopamine, and somatostatin in the hypothalamus of parous animals was observed. Further, we also observed that pregnancy had a significant effect on the pituitary gland and its response to growth hormone and prolactin secretagogues. Our studies using the rodent model system demonstrate that pregnancy could be reducing the risk of breast cancer by persistently altering the hypothalamic–pituitary axis, which could have implications for breast cancers in humans as well.https://www.mdpi.com/2072-6694/13/13/3207pregnancymammary cancerhypothalamuspituitaryhormones |
| spellingShingle | Ramadevi Subramani Adriana Estrada Madeline Dixon Maria Parada Sheryl Rodriguez Diego A. Pedroza Matthew D. Ramirez Alexa Clift Lilia Garcia Rajkumar Lakshmanaswamy Pregnancy Inhibits Mammary Carcinogenesis by Persistently Altering the Hypothalamic–Pituitary Axis Cancers pregnancy mammary cancer hypothalamus pituitary hormones |
| title | Pregnancy Inhibits Mammary Carcinogenesis by Persistently Altering the Hypothalamic–Pituitary Axis |
| title_full | Pregnancy Inhibits Mammary Carcinogenesis by Persistently Altering the Hypothalamic–Pituitary Axis |
| title_fullStr | Pregnancy Inhibits Mammary Carcinogenesis by Persistently Altering the Hypothalamic–Pituitary Axis |
| title_full_unstemmed | Pregnancy Inhibits Mammary Carcinogenesis by Persistently Altering the Hypothalamic–Pituitary Axis |
| title_short | Pregnancy Inhibits Mammary Carcinogenesis by Persistently Altering the Hypothalamic–Pituitary Axis |
| title_sort | pregnancy inhibits mammary carcinogenesis by persistently altering the hypothalamic pituitary axis |
| topic | pregnancy mammary cancer hypothalamus pituitary hormones |
| url | https://www.mdpi.com/2072-6694/13/13/3207 |
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