Endocrine hormones are important factors in maintaining pregnancy as well as initiation of parturition. Progesterone is the major hormone maintaining myometrium quiescence, while glucocorticoids, prostaglandins and estrogen are among the major hormones involved in the initiation of parturition. Therefore progesterone withdrawal at the end of pregnancy is the prerequisite for the initiation of parturition. However, unlike most of the other species of mammals that the withdrawal of progesterone is achieved via reduction of progesterone synthesis or increased conversion of progesterone to estrogen, some mammals including the primates maintain high progesterone level throughout gestation and even during parturition. Accumulating lines of evidence indicate that the withdrawal of progesterone in human being is attained via the changes of the expression ratio of progesterone receptor subtypes and the changes of co-activators required for the activation of transcriptional activity of progesterone receptor. Here we reviewed the three major mechanisms, namely luteolysis, upregulation of placental P450c17 hydroxylase and changes of progesterone receptor functions, underlying progesterone withdrawal in late pregnancy in mammals.
Animals ; Female ; Humans ; Luteolysis ; physiology ; Parturition ; metabolism ; physiology ; Pregnancy ; Pregnancy Trimester, Third ; metabolism ; physiology ; Progesterone ; metabolism ; Receptors, Progesterone ; metabolism ; physiology ; Species Specificity ; Steroid 17-alpha-Hydroxylase ; metabolism

A single measurement of serum 17alpha-hydroxyprogesterone (17OHP) level can be unreliable because of its marked diurnal variation. We investigated the relationship of serum level of 17OHP with that of androstenedione (AD), which shows a smaller diurnal variation. And we tested whether the responses of these two hormones to low-dose ACTH stimulation are correlated in patients with 21-hydroxylase deficiency. Baseline serum 17OHP and AD levels were measured in 87 patients and a low-dose ACTH stimulation test was performed in 41 patients. The basal 17OHP level correlated positively with the basal AD level independently of sex, type of 21-hydroxylase deficiency, and the time of day of blood sampling (n = 87, R2 = 0.75, P < 0.001). The area under the curve of 17OHP and AD correlated positively with their respective basal levels. The fold-change increase in 17OHP after ACTH injection correlated negatively with the basal 17OHP level, but that of AD did not correlate with the basal AD level. The random serum 17OHP level, used in the clinic, is a reliable guide and a low-dose ACTH stimulation test provides no extra benefit for assessing the treatment adequacy in patients with 21-hydroxylase deficiency.
17-alpha-Hydroxyprogesterone/*blood ; Adolescent ; Adrenal Hyperplasia, Congenital/*diagnosis/drug therapy ; Adrenocorticotropic Hormone/*diagnostic use ; Androstenedione/*blood ; Circadian Rhythm ; Female ; Humans ; Male ; Steroid 21-Hydroxylase/metabolism ; Young Adult

OBJECTIVETo investigate the clinical and genetic characteristics of 7 patients from 5 families with 17a-hydroxylase/17,20 lyase deficiency (17OHD) and the CYP17A1 mutation in Chinese.

METHODSClinical features and laboratory data were collected from 5 families with 17OHD. PCR direct sequencing was performed to screen the mutation of CYP17A1 gene of the patients. Polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) and sequencing were performed to screen the mutations of CYP17A1 gene in 288 healthy individuals from Shandong province.

RESULTSSeven patients (5 of them were 46,XX; 2 were 46,XY) had typical clinical presentation of sexual infantilism, hypertension and hypokalemia. Hormone profile indicated decreased plasma cortisol and sex hormones, and elevated blood adrenocorticotrophic hormone (ACTH). TAC329AA and H373L in exon 6 and D487_F489del in exon 8 were identified from the patients. One heterozygote for D487_F489del was identified in 288 healthy controls.

CONCLUSIONThe TAC329AA and D487_F489del of the CYP17A1 gene were the most frequent mutations in Chinese with 17OHD.There might be certain frequency of heterozygotes for D487_F489del in Chinese population.

Adolescent ; Adult ; Asian Continental Ancestry Group ; genetics ; Exons ; Female ; Gene Frequency ; Humans ; Hypertension ; genetics ; Hypokalemia ; genetics ; Male ; Middle Aged ; Molecular Sequence Data ; Mutation ; Pedigree ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Sexual Infantilism ; genetics ; metabolism ; Steroid 17-alpha-Hydroxylase ; genetics ; metabolism ; Steroid 21-Hydroxylase ; genetics ; metabolism ; Young Adult

Animals ; Autophagy/genetics* ; Cholesterol/metabolism* ; Gene Expression Regulation ; Integrases/metabolism* ; Leydig Cells/metabolism* ; Male ; Mice, Knockout ; Multienzyme Complexes/metabolism* ; Phosphoproteins/metabolism* ; Primary Cell Culture ; Progesterone Reductase/metabolism* ; RNA Splicing Factors/metabolism* ; Scavenger Receptors, Class B/metabolism* ; Sequestosome-1 Protein/metabolism* ; Signal Transduction ; Sirtuin 1/genetics* ; Sodium-Hydrogen Exchangers/metabolism* ; Steroid 17-alpha-Hydroxylase/metabolism* ; Steroid Isomerases/metabolism* ; Testosterone/genetics*

OBJECTIVETo investigate the CYP17A1 gene mutations in a Chinese 46,XX patient with partial combined 17 alpha-hydroxylase/17,20-lyase deficiency.

METHODSClinical data were retrospectively analyzed. The genomic DNA of the patient and her parents was isolated from whole blood. Seven pairs of primers were used to amplify eight exons and exon-intron boundaries of the CYP17A1 gene. The amplified PCR products were purified by agarose gel and then directly sequenced. In order to confirm the DNA sequences of different alleles, some fragments were inserted into pMD 18-T vector and then subclone sequenced. Sequencing results were compared to the established human CYP17A1 sequence.

RESULTSThe patient was new compound heterozygous of 5994-5995 delAT/7541 C>T. The mutation 5994-5995 del AT, causing amino acid I259H, 274X, was proposed to result early truncated protein which was lack of the activity center site of P450C17, whereas missense mutation 7541 C>T causing A398V did not lie in the active site of the enzyme according to the computer model of human P450C17. The 46, XX case had irregular menstruation and slightly hypertension and hypokalemia. The ACTH stimulating test as well as the result of the sex hormones suggested that there was partial 17 alpha-hydroxylase/17, 20-lyase enzyme activities in the adrenal and sexual gland. We speculate that A398V might conserve partial of the enzyme's activities. The genotype was coincident with phenotype.

CONCLUSIONMore study should be done to have better understanding of the function of the mutated P450C17 enzymes.

Adrenal Hyperplasia, Congenital ; enzymology ; genetics ; Base Sequence ; DNA Mutational Analysis ; Exons ; genetics ; Female ; Heterozygote ; Humans ; Introns ; genetics ; Mutation ; Polymerase Chain Reaction ; Steroid 17-alpha-Hydroxylase ; genetics ; metabolism ; Young Adult

BACKGROUNDEndogenous estrogen plays a very important role in the carcinogenesis and progression of breast cancer. The enzymes involved in the biosynthesis and metabolism of estrogen have been proposed to contribute to this effect. To examine this hypothesis, we conducted a case-control study to investigate the relationship between polymorphisms of genes responsible for estrogen biosynthesis (CYP17, cytochrome P450c17a and CYP19, aromatase cytochrome P450) and estrogen sulfation of inactivation (SULT1A1, sulfotransferase1A1) and the risk of breast cancer in Chinese women.

METHODSThis study involved 213 breast cancer patients and 430 matched controls. PCR-based restriction fragment length polymorphism (RFLP) and short tandem repeat polymorphism (STRP) assays were used to detect the mononucleotide transition of CYP17 and SULT1A1 and tandem repeat polymorphism of CYP19. Logistic regression analyses were used to determine OR and 95% CI of each and all three high-risk genotypes, of all three genotypes combined, and of estrogen exposure factors. The relationship between each high-risk genotype and clinicalpathological characteristics were also assessed.

RESULTSThe frequency of A2 allele of CYP17 was 49.8% in cases and 49.1% in controls (P = 0.82). The frequency of His allele of SULT1A1 was significantly higher in cases (13.6%) than in controls (9.5%) (P < 0.05). There was also significant difference of the (TTTA) 10 allele of CYP19 which was 12.4% in cases and 8.2% in controls (P < 0.05). When the CYP17 A2 allele, CYP19 (TTTA) 10 and SULT1A1 His allele were considered as the "putative high-risk" genotype, there was an increased risk of breast cancer with the number of high-risk genotypes in a dose-response effect (trend, P = 0.05). In multivariate analysis, the SULT1A1 genotype remained the most significant determinant for breast cancer, with OR = 2.37 (95% CI 1.23-4.74), followed by CYP19, with OR = 1.75 (95% CI 1.27-3.56). The (TTTA) 10 allele of CYP19 was associated with tumor size, and the His allele of SULT1A1 associated with status of lymph node metastasis.

CONCLUSIONSThis study supports the hypothesis that breast cancer can be initiated by estrogen exposure and that estrogen metabolizing genes are involved in this mechanism. This multigenic model is useful for identifying individuals who are at higher risks of breast cancer.

Adult ; Aged ; Aromatase ; genetics ; Arylsulfotransferase ; genetics ; Breast Neoplasms ; etiology ; genetics ; Case-Control Studies ; Estrogens ; metabolism ; Female ; Genetic Predisposition to Disease ; Humans ; Middle Aged ; Polymorphism, Genetic ; Risk Factors ; Steroid 17-alpha-Hydroxylase ; genetics

The steroidal enzyme cytochrome P45017alpha catalyzes the conversion of progesterone and pregnenolone into androgens, androstenedione and dehydroepiandrosterone, respectively, the direct precursors of estrogens and testosterone. Dihydrotestosterone is the principal active androgen in the prostate, testosterone is also an active stimulant of the growth of prostatic cancer tissue. Inhibition of this enzyme as a mechanism for inhibiting androgen biosynthesis could be a worthwhile therapeutic strategy for the treatment of PCA. In this paper, four categories of steroidal inhibitors of cytochrome P45017alpha will be reviewed, a diverse range of steroidal inhibitors had been synthesized and shown to be potent inhibitors of P45017alpha.
Androstenedione ; biosynthesis ; Androstenes ; Androstenols ; chemical synthesis ; chemistry ; pharmacology ; Animals ; Antineoplastic Agents ; chemical synthesis ; chemistry ; pharmacology ; Dehydroepiandrosterone ; biosynthesis ; Dihydrotestosterone ; metabolism ; Enzyme Inhibitors ; chemical synthesis ; chemistry ; pharmacology ; Humans ; Male ; Molecular Structure ; Pregnenolone ; metabolism ; Progesterone ; metabolism ; Prostatic Neoplasms ; pathology ; Steroid 17-alpha-Hydroxylase ; antagonists & inhibitors ; Testosterone ; biosynthesis

CYP17 gene is involved in steroidogenesis and steroid metabolism. Epidemiologic results on the association between the CYP17 polymorphism and breast cancer risk have been inconsistent. We examined the association between the MspAI polymorphism at +27 relative to the start of transcription in the 5'-untranslated region of CYP17 gene and breast cancer risk in Korean women. Four hundred and sixty-two incident cases and 337 controls were recruited from three teaching hospitals in Seoul during 1994-2001. Polymorphism of the CYP17 gene was determined by a single base extension assay. Demographic and lifestyle characteristics were identified using structured questionnaire. Age-adjusted (aOR) and multivariate odds ratios (mOR) and 95% confidence intervals (CI) were estimated by unconditional logistic regression. The proportions of A1/A1, A1/A2 and A2/A2 genotypes among controls were 20.8%, 45.1% and 34.1%, respectively. Compared to the A1/A1 genotype, A1/A2 or A2/A2 genotype was not statistically significantly associated with overall breast cancer risk (i.e., mOR=1.01, 95% CI=0.69-1.47 and mOR=0.76, 95% CI=0.51-1.14, respectively). However, a significant association between CYP17 A2/A2 genotype and breast cancer was observed among women aged 50 years or less (mOR=0.58, 95% CI=0.34-0.99, P=0.04) and leaner women (body mass index < 22 kg/m2) (mOR=0.48, 95% CI=0.23-0.97, P=0.04). Our results suggest that genetic polymorphism in 5'-untranslated region of CYP17 might play a role in breast cancer development in Korean women among younger women aged less than 50 or leaner women with body mass index less than 22 kg/m2.
5' Untranslated Regions/*genetics ; Breast/metabolism/pathology ; Breast Neoplasms/enzymology/epidemiology/*genetics ; Case-Control Studies ; Comparative Study ; Demography ; Female ; *Genetic Predisposition to Disease ; Genotype ; Humans ; Korea/epidemiology ; Middle Aged ; Odds Ratio ; Polymorphism, Genetic/*genetics ; Questionnaires ; Research Support, Non-U.S. Gov't ; Risk Factors ; Steroid 17-alpha-Hydroxylase/*genetics

OBJECTIVETo investigate the CYP17A1 gene mutations in Chinese patients with 17 alpha-hydroxylase/17, 20-lyase deficiency.

METHODSClinical data were retrospectively analyzed. The CYP17A1 gene mutations were detected in 5 cases with 17 alpha-hydroxylase/17, 20-lyase deficiency and their relatives. The genomic DNA of the patients was isolated from whole blood. Seven pairs of primers were used to amplify eight exons and exon-intron boundaries of the CYP17A1 gene. The amplified PCR products were purified by agarose gel and then directly sequenced. In order to confirm the DNA sequences of different alleles, some fragments were inserted into pMD 18-T vector and then sequenced. Sequencing results were compared to the established human CYP17A1 sequence.

RESULTSBriefly, we found 2 kinds of compound mutations, of which were: (1) 6436-6438(TAC-->AA), causing amino acid Y329K, 418X; (2) 6531-6532(GC-->A), causing amino acid L361F, 418X. Among the five cases, four were homozygous for 6436-6438(TAC-->AA), whereas one was compound heterozygous for 6436-6438(TAC-->AA)/6531-6532(GC-->A). The clinical characteristics of 5 cases were all completely combined defects of 17 alpha-hydroxylase/17, 20-lyase, and they all carried two alleles of CYP17A1 gene mutations that all shifted the reading frame and resulted in truncated protein which lack of the activity center site of P450C17, of which corresponding with their clinical feature.

CONCLUSIONNine alleles have the mutation of 6436-6438(TAC-->AA), accounting for 90% of total alleles (9/10). That suggests this kind of mutation may have racial specificity. More study should be done to have better understanding of the function of the truncated P450C17 enzymes.

Adolescent ; Adrenal Hyperplasia, Congenital ; enzymology ; genetics ; Alleles ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; DNA ; DNA Mutational Analysis ; DNA Primers ; Exons ; genetics ; Humans ; Male ; Molecular Sequence Data ; Mutation ; Point Mutation ; Polymerase Chain Reaction ; Sexual Infantilism ; genetics ; Steroid 17-alpha-Hydroxylase ; genetics ; metabolism ; Young Adult

Congenital adrenal insufficiency is caused by specific genetic mutations. Early suspicion and definite diagnosis are crucial because the disease can precipitate a life-threatening hypovolemic shock without prompt treatment. This study was designed to understand the clinical manifestations including growth patterns and to find the usefulness of ACTH stimulation test. Sixteen patients with confirmed genotyping were subdivided into three groups according to the genetic study results: congenital adrenal hyperplasia due to 21-hydroxylase deficiency (CAH, n=11), congenital lipoid adrenal hyperplasia (n=3) and X-linked adrenal hypoplasia congenita (n=2). Bone age advancement was prominent in patients with CAH especially after 60 months of chronologic age (n=6, 67%). They were diagnosed in older ages in group with bone age advancement (P<0.05). Comorbid conditions such as obesity, mental retardation, and central precocious puberty were also prominent in this group. In conclusion, this study showed the importance of understanding the clinical symptoms as well as genetic analysis for early diagnosis and management of congenital adrenal insufficiency. ACTH stimulation test played an important role to support the diagnosis and serum 17-hydroxyprogesterone levels were significantly elevated in all of the CAH patients. The test will be important for monitoring growth and puberty during follow up of patients with congenital adrenal insufficiency.
17-alpha-Hydroxyprogesterone/blood ; 46, XY Disorders of Sex Development/drug therapy/*genetics ; Adolescent ; Adrenal Hyperplasia, Congenital/drug therapy/*genetics ; Adrenal Insufficiency/*congenital/diagnosis/drug therapy/genetics ; Adrenocorticotropic Hormone/*metabolism ; Bone Development/genetics ; Child ; Child, Preschool ; DAX-1 Orphan Nuclear Receptor/genetics ; Female ; Genetic Diseases, X-Linked/drug therapy/*genetics ; Genotype ; Glucocorticoids/therapeutic use ; Humans ; Intellectual Disability/complications ; Male ; Mineralocorticoids/therapeutic use ; Obesity/complications ; Phosphoproteins/genetics ; Puberty, Precocious/complications ; Retrospective Studies ; Steroid 21-Hydroxylase/genetics