scholarly journals The influence of sex steroid hormones on ferrochelatase gene expression in Harderian gland of hamster (Mesocricetus auratus)

2006 ◽  
Vol 189 (1) ◽  
pp. 103-112 ◽  
Author(s):  
F Vilchis ◽  
L Ramos ◽  
C Timossi ◽  
B Chávez
Keyword(s):  
Amino Acid ◽  
Steroid Hormones ◽  
Protoporphyrin Ix ◽  
Harderian Gland ◽  
Active Role ◽  
Structural Features ◽  
Sex Steroid Hormones ◽  
Sex Steroid ◽  
Amino Acid Residues ◽  
Haem Proteins

Ferrochelatase (protohaem ferrolyase, EC 4.99.1.1), the terminal enzyme of the haem biosynthetic pathway, catalyses the insertion of ferrous iron into protoporphyrin IX to form protohaem. The Syrian hamster Harderian gland (HG) is known for its ability to produce and accumulate large amounts of protoporphyrins. In this species, the female gland contains up to 120 times more porphyrin than the male gland. Data from biochemical studies suggest that this gland possesses the enzymatic complex for haem biosynthesis but lacks ferrochelatase activity. The abundance of intraglandular haem proteins does not support this idea. To gain more insight into this process, we isolated cDNA for ferrochelatase from hamster liver, using the 5′- and 3′- rapid amplification of complementary DNA ends (RACE), and investigated its expression in HG from males and females. The full-length cDNA comprises an open reading frame of 1269 bp encoding a polypeptide of 422 amino-acid residues. Hamster DNA sequence exhibits 92% identity to mouse and 87% identity to human sequences. The predicted hamster enzyme was shown to have structural features of mammalian ferrochelatase, including a putative NH2- terminal presequence, a central core of about 330 amino-acid residues and an extra 30–50-amino-acid stretch at the carboxyl-terminus. RNA blotting experiments indicated that this cDNA hybridized to a liver mRNA of about 2.1 kb, while a weak hybridization signal was observed with mRNA from HG preparations. RT–PCR assays confirmed the expression of specific transcripts in both tissues. Male glands contained approximately twofold more enzyme mRNA than female glands. Likewise, the intraglandular content of mRNA varied during the oestrous cycle, with the highest levels found in the oestrous phase. These cyclic variations were less evident in liver. Ovariectomy plus treatment with progesterone or 17β-oestradiol plus progesterone increased ferrochelatase mRNA of the gland. In HG of short- or long-term castrated males, the administration of testosterone did not affect the ferrochelatase mRNA concentration. Based on mRNA expression levels, we conclude that Harderian ferrochelatase may play an active role in maintaining the physiological pool of haem required for processing cytochromes and other glandular haem proteins. Likewise, the sex-steroid hormones appear to have only a modest influence upon Harderian ferrochelatase.

scholarly journals Associations between female lung cancer risk and sex steroid hormones: a systematic review and meta-analysis of the worldwide epidemiological evidence on endogenous and exogenous sex steroid hormones

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hui Zeng ◽  
Zhuoyu Yang ◽  
Jiang Li ◽  
Yan Wen ◽  
Zheng Wu ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Cancer Risk ◽  
Steroid Hormones ◽  
Lung Cancer Risk ◽  
Meta Analysis ◽  
Sex Steroid Hormones ◽  
Sex Steroid ◽  
Sex Steroid Hormone ◽  
Hormone Exposure ◽  
Female Lung Cancer

Abstract Background Published findings suggest sex differences in lung cancer risk and a potential role for sex steroid hormones. Our aim was to perform a meta-analysis to investigate the effects of sex steroid hormone exposure specifically on the risk of lung cancer in women. Methods The PubMed, MEDLINE, Web of Science, and EMBASE databases were searched. The pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) for female lung cancer risk associated with sex steroid hormones were calculated overall and by study design, publication year, population, and smoking status. Sensitivity analysis, publication bias, and subgroup analysis were performed. Results Forty-eight studies published between 1987 and 2019 were included in the study with a total of 31,592 female lung cancer cases and 1,416,320 subjects without lung cancer. Overall, higher levels of sex steroid hormones, both endogenous (OR: 0.92, 95% CI: 0.87–0.98) and exogenous (OR: 0.86, 95% CI: 0.80–0.93), significantly decreased the risk of female lung cancer by 10% (OR: 0.90, 95% CI: 0.86–0.95). The risk of lung cancer decreased more significantly with a higher level of sex steroid hormones in non-smoking women (OR: 0.88, 95% CI: 0.78–0.99) than in smoking women (OR: 0.98, 95% CI: 0.77–1.03), especially in Asia women (OR: 0.84, 95% CI: 0.74–0.96). Conclusions Our meta-analysis reveals an association between higher levels of sex steroid hormone exposure and the decreased risk of female lung cancer. Surveillance of sex steroid hormones might be used for identifying populations at high risk for lung cancer, especially among non-smoking women.

Circulating Levels of Sex Steroid Hormones and Gastric Cancer

2021 ◽  
Author(s):  
Yelda A. Leal ◽  
Minkyo Song ◽  
Jovanny Zabaleta ◽  
Gilberto Medina-Escobedo ◽  
Patrick Caron ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Steroid Hormones ◽  
Sex Steroid Hormones ◽  
Sex Steroid ◽  
Circulating Levels

Associations between circulating sex steroid hormones and cognition in normal elderly women

Neurology ◽  
2000 ◽  
Vol 54 (3) ◽  
pp. 599-599 ◽  
Author(s):  
E. B. Drake ◽  
V. W. Henderson ◽  
F. Z. Stanczyk ◽  
C. A. McCleary ◽  
W. S. Brown ◽  
...  
Keyword(s):  
Steroid Hormones ◽  
Elderly Women ◽  
Sex Steroid Hormones ◽  
Sex Steroid

scholarly journals Multiple Distinct Sets of Stereotyped Antigen Receptors Indicate a Role for Antigen in Promoting Chronic Lymphocytic Leukemia

2004 ◽  
Vol 200 (4) ◽  
pp. 519-525 ◽  
Author(s):  
Bradley T. Messmer ◽  
Emilia Albesiano ◽  
Dimitar G. Efremov ◽  
Fabio Ghiotto ◽  
Steven L. Allen ◽  
...  
Keyword(s):  
Amino Acid ◽  
B Cell ◽  
Structural Features ◽  
Lymphocytic Leukemia ◽  
Cell Subpopulation ◽  
Amino Acid Residues ◽  
Antigen Receptors ◽  
Region Gene ◽  
V Region ◽  
Unique Amino Acid

Previous studies suggest that the diversity of the expressed variable (V) region repertoire of the immunoglobulin (Ig)H chain of B-CLL cells is restricted. Although limited examples of marked constraint in the primary structure of the H and L chain V regions exist, the possibility that this level of restriction is a general principle in this disease has not been accepted. This report describes five sets of patients, mostly with unmutated or minimally mutated IgV genes, with strikingly similar B cell antigen receptors (BCRs) arising from the use of common H and L chain V region gene segments that share CDR3 structural features such as length, amino acid composition, and unique amino acid residues at recombination junctions. Thus, a much more striking degree of structural restriction of the entire BCR and a much higher frequency of receptor sharing exists among patients than appreciated previously. The data imply that either a significant fraction of B-CLL cells was selected by a limited set of antigenic epitopes at some point in their development and/or that they derive from a distinct B cell subpopulation with limited Ig V region diversity. These shared, stereotyped Ig molecules may be valuable probes for antigen identification and important targets for cross-reactive idiotypic therapy.

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