Cytestrol acetate is a

steroid A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and a ...

antiestrogen Antiestrogens, also known as estrogen antagonists or estrogen blockers, are a class of drugs which prevent estrogens like estradiol from mediating their biological effects in the body. They act by blocking the estrogen receptor (ER) and/or inhi ...

and a

cytostatic Cytostasis (cyto – cell; stasis – stoppage) is the inhibition of cell growth and multiplication. Cytostatic refers to a cellular component or medicine that inhibits cell division. Cytostasis is an important prerequisite for structured multic ...

antineoplastic agent Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (list of chemotherapeutic agents, chemotherapeutic agents or alkylating agents) as part of a standardized ...

(i.e.,

chemotherapeutic Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemotherap ...

) which was developed for the treatment of

breast cancer Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or a re ...

but was never marketed.Smirnova Z. S, (2003). xperimental Study of Hormonocytostatics for Treatment of Breast Cancer.Российский биотерапевтический журнал, 2(2).Смирнова, З. С., Ржезников, В. М., Толкачев, В. Н., Борисова, Л. М., Киселева, М. П., Семейкин, А. В., ... & Шимановский, Н. Л. (2014). Противоопухолевое и антипролиферативное действие стероидного антиэстрогена цитэстрола ацетата на моделях гормонозависимых опухолей. Экспериментальная и клиническая фармакология, 77(10), 31-35. It is an 11α-

hydroxyl In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy ...

ated

derivative In mathematics, the derivative of a function of a real variable measures the sensitivity to change of the function value (output value) with respect to a change in its argument (input value). Derivatives are a fundamental tool of calculus. F ...

ethinylestradiol Ethinylestradiol (EE) is an estrogen medication which is used widely in birth control pills in combination with progestins. In the past, EE was widely used for various indications such as the treatment of menopausal symptoms, gynecological disord ...

in which a bis(2-chloroethyl)amine

nitrogen mustard Nitrogen mustards are cytotoxic organic compounds with the chloroethylamine (Cl(CH2)2NR2) functional group. Although originally produced as chemical warfare agents, they were the first chemotherapeutic agents for treatment of cancer. Nitrogen m ...

moiety Moiety may refer to: Chemistry * Moiety (chemistry), a part or functional group of a molecule ** Moiety conservation, conservation of a subgroup in a chemical species Anthropology * Moiety (kinship), either of two groups into which a society is ...

has been attached as an

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ar ...

at the C3 position and

acetate An acetate is a salt (chemistry), salt formed by the combination of acetic acid with a base (e.g. Alkali metal, alkaline, Alkaline earth metal, earthy, Transition metal, metallic, nonmetallic or radical Radical (chemistry), base). "Acetate" als ...

esters have been attached at the C11α and C17β positions. The

mechanism of action In pharmacology, the term mechanism of action (MOA) refers to the specific biochemical interaction through which a drug substance produces its pharmacological effect. A mechanism of action usually includes mention of the specific molecular targe ...

of cytestrol acetate in breast cancer is two-fold: (1) acting as an antiestrogen similarly to

fulvestrant Fulvestrant, sold under the brand name Faslodex among others, is a medication used to treat hormone receptor (HR)-positive metastatic breast cancer in postmenopausal women with disease progression as well as HR-positive, HER2-negative advanced br ...

ICI-164384 ICI-164384, also known as ''N''-''n''-butyl-''N''-methyl-11-(3,17β-dihydroxyestra-1,3,5(10)-trien-7α-yl)undecanamide, is a steroidal antiestrogen and a synthetic derivative of estradiol which is closely related to fulvestrant and was never mark ...

; and (2) having

actions via the carbamate–nitrogen mustard moiety analogously to

estramustine phosphate Estramustine phosphate (EMP), also known as estradiol normustine phosphate and sold under the brand names Emcyt and Estracyt, is a dual estrogen and chemotherapy medication which is used in the treatment of prostate cancer in men. It is taken ...

. The drug shows potent

efficacy Efficacy is the ability to perform a task to a satisfactory or expected degree. The word comes from the same roots as ''effectiveness'', and it has often been used synonymously, although in pharmacology a pragmatic clinical trial#Efficacy versu ...

against breast cancer superior to that of

tamoxifen Tamoxifen, sold under the brand name Nolvadex among others, is a selective estrogen receptor modulator used to prevent breast cancer in women and treat breast cancer in women and men. It is also being studied for other types of cancer. It has b ...

in ''

in vitro ''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology an ...

'' models.

References

Acetate esters Antiestrogen esters Antiestrogens Antineoplastic drugs Carbamates Hormonal antineoplastic drugs Nitrogen mustards Organochlorides Prodrugs Russian drugs Chloroethyl compounds {{Antineoplastic-drug-stub

See also

References