Optical Metabolic Synthesis

Another factor that contributes to the development of breast cancer is actually the hormone estrogen. This seems unusual because estrogen is a hormone that is essential to the bodies of women in various ways. Estrogen is necessary for normal growth and development of breasts and reproductive organs, as well as for the maintenance of a healthy heart and bones. However, lifetime estrogen exposure may increase a woman’s risk of developing breast cancer. It does not actually produce the mutation in the DNA, nevertheless Estrogen stimulates the proliferation of breast cells that already contain a mutation. These mutated cells will continue to reproduce and have an increased chance of becoming cancerous.

To grow and reproduce, breast cancer cells require the female hormone estrogen. Tamoxifen is an "anti-estrogen" and works by competing with estrogen to bind to estrogen receptors in breast cancer cells. Tamoxifen is formally known as a selective estrogen receptor modulator (SERM). By blocking estrogen in the breast, tamoxifen helps slow the growth and reproduction of breast cancer cells. While tamoxifen fights estrogen in breast cancer cells, it also mimics the positive effects of estrogen in other body systems. Post-menopausal women who take tamoxifen may decrease their risk of heart disease or osteoporosis (a degenerative bone disease) without having to use hormone replacement therapy (HRT ).

Breast cancer is a popular disease that many people are afraid of. It is the growth of altered genes that create malignant tumors starting in a female or male’s breast tissue. Cancer has a reputation of being caused by hormones, but that may not always be the case. Hormones are chemicals that work as chemical messengers in the body and affect the duties of cells and tissues. The ovaries in premenopausal and postmenopausal women usually produce the hormones, like estrogen and progesterone. The hormone estrogen develops and maintains the female sex features and progesterone have to do with women 's menstrual cycle and pregnancy. In a breast cancer cell, it

“The Breast are considered to be in the reproductive system because they are able to produce milk during childbirth” ("Breast Pictures, Anatomy & Anatomy | Body Maps," 2005). There are many risk factors that increase a woman’s chances of developing breast cancer, but it is not yet known exactly how some of these risk factors cause cells to become cancerous. Some of the few risk factors that are included are taking

“Although most of the breast cancers are not hereditary there are genes that determine the likelihood of getting breast cancer. This includes genes like BRCA1 and BRCA2 that can increase the risk of developing both breast and ovarian cancer” (Mandal, 2013). Furthermore, exposure to diethylstilbestrol (DES) can increase an individual’s chances of getting breast cancer. Age and height are also another risk factor. Taller and older women are more likely to be diagnosed with the disease (Mandal, 2013). Lastly, increased exposure to estrogen can cause breast cancer. Women who get their period at and young age and enter menopause at a later age are exposed to longer durations of estrogen (Mandal, 2013).

Throughout the years, the leading cause of death in both male and females across the globe is cancer. Even though the ordinary human body possesses forty-six chromosomes, cancer can arise from genetic mutations or DNA chromosome damage. Furthermore, cancer is considered one of the deadliest and lethal diseases since cancer cells create malignant tumors within the body leading up to organ failure if cancer cells avoid detection. In females, the leading cause of breast cancer is the level of estrogen in the female body as well as estrogen exposure with the environment. Breast cancer occurs in women since the breasts of a woman are mammary glands surrounded by fatty and fibrous connective tissue. Similar to other body parts, the female breasts

Tamoxifin selectively and competitively bind/block estrogen receptor resulting in inhibition of estrogen mediated gene expression and proliferation thereby suppressing growth of tumor in breast tissues. Although Tamoxifen is highly efficient in its performance but recently it has been demonstrated that patients with all stages of ER positive breast cancer become immune to Tamoxifen under prolonged Tamoxifen treatment. The mechanism of this resistance is still not clear however; recently workers have demonstrated that Tamoxifen effect is overridden by increase in other growth factor signaling pathways. This Tamoxifen override can be rescued by inhibiting growth factor signaling pathways. Cumulative clinical studies suggests that the most common growth factors associated with Tamoxifen resistance include overexpression of EGFR, HER-2, and elevated levels of Akt or ERK in few cases if not all. In vivo studies have shown overexpression of HER-2 in 10% of Tamoxifen treated ER positive breast cancers, one mechanism of Tamoxifin resistance where Tamoxifen acts as estrogen and activates HER-2 which in turn phosphorylates ER and A1B1 (SRC3) protein, leading to proliferation of cells. Stress and/or signaling pathways also contribute to Tamoxifen resistance. Studies support the hypothesis that phosphorylated members of jun N-terminal kinase (JNK) and mitogen- activated protein kinase (MAPK) also contribute to Tamoxifen

The most common subtype is a well-differentiated carcinoma (grade 1 or 2 endometrioid histology) that behaves in an indolent fashion, causes bleeding symptoms in its early stages, and is curable in most cases. Risk factors for this low-risk subtype are well known and are related to an increase in circulating estrogens: obesity, chronic anovulation and nulliparity, estrogen replacement therapy (unopposed by progesterone), and tamoxifen use. PTEN gene mutation in 30 -80% of cases

It is known that cancer, in general, is a group of diseases that is characterized by the out-of-control growth and spread of a group of abnormal cells, which can often times result in death. More specifically, breast cancer is a hormonally dependent disease, which causes malignancy in the epithelial cells of the ducts and/or lobules of the breast (Lippman, 2012). Therefore, “women without functioning ovaries, who never receive estrogen-replacement therapy, do not develop breast cancer” (Lippman, 2012).

In United Kingdom, breast cancer is the most common cancer. In 2013, there were around 53, 400 cases diagnosed in females and 340 cases diagnosed in males (Cancer Research UK, 2013). The survival rate is five years or more for almost all women with breast cancer diagnosed at an earlier stage, as compared to three in twenty women with breast cancer diagnosed at the latest stage. Breast cancer is the second most common cause of death in females after lung cancer. The risk factors of breast cancer are due to lifestyle and other risk factors. Lifestyle factors include obesity, diet, alcohol consumption and occupational exposures such as ionizing radiation. Other risk factors include age, genetics, oral contraceptives and certain hormone replacement therapy.

Studies have shown that high estrogen levels correspond with an increased risk for breast cancer in mammalian species (3). The hormone estrogen plays a key role in mammary gland development by binding to the estrogen receptor, which has previously been identified as a transcription factor. In normal cells, when estrogen binds to the receptor, a dimer forms and a conformational change occurs. The estrogen receptor travels to the nucleus where its DNA binding domain interacts with a DNA sequence found in the promoter of several genes. The estrogen receptor must form a complex with various proteins prior to initiation of transcription. In cancerous cells, the estrogen receptor becomes overly-activated by estrogen and leads to tumor formation via multiple mechanisms (3).

Chemicals are also suspected to cause breast cancer. Xenoestrogens are chemicals with estrogen-like effects, they are found in pesticides and other common industrial products. Other estrogen-like chemicals that have a stronger association with breast cancer include dieldrin and beta-hexachloraocyclohexane. Although these chemicals are very weak estrogens, one study showed that exposure to single weak-estrogen compounds isn’t a big risk but a combination of two or more chemicals result in extremely high estrogenic

CYP2E1 is a major cytochorme found to be involved in carbon-chlorine bond reductive cleavage and biotransformation of CCl4 to trichloromethyl radical (CCl3•). These cytochrome systems catalyze many reactions involved in drug metabolism and synthesis of cholesterol and other lipid metabolites both in endogenous substrates, such as ethanol and acetone as well as exogenous substrates which includes carbon tetrachloride (Tang et al., 2013). In the presence of oxygen, CCl3• generates the highly reactive metabolites such as trichloromethyl peroxy (CCl3OO•) free radicals which covalently bind to the cellular macromolecules, lipids and polyunsaturated fatty acids in the cellular membrane. Trichloromethyl peroxy (CCl3OO•) free radicals react with suitable substrates to complete its electron pair. CCl3OO• is

The impact of certain estrogenic xenobiotics on the reproductive system development and health of animals has been clearly documented. Findings, such as ours demonstrate thathumans are also exposed at risk. As data accumulate regarding to infertility, genital tract malformations and increasing cancer rates in estrogen target tissues (especially the breast),

The concept of mTOR inhibition in breast cancer was firstly supported by preclinical evidence demonstrating activation of the PI3K/mTOR pathway after long-term estrogen deprivation [13,14]; estrogen-deprived cells relied heavily on the PI3K signaling pathway, making this an important mechanism of acquired endocrine resistance. Combined use of anti-estrogens (tamoxifen/ letrosole) with rapamycin analogues demonstrated increased anti-tumour activity and reversal of endocrine resistance secondary to PI3K/mTOR activation in preclinical models [15-18].