The influence of androgens, anti-androgens, and castration on cell proliferation in the jejunal and colonic crypt epithelia, and in dimethylhydrazine-induced adenocarcinoma of rat colon

Role of gonadally synthesized steroid hormones in the colorectal cancer microenvironment

Objective

To understand the relationship between steroid hormones synthesized by the gonads and colorectal cancer as well as its tumor microenvironment, in the expectation of providing new ideas in order to detect and treat colorectal cancer.

Methods

Through reviewing the relevant literature at home and abroad, we summarized that androgens promote the growth of colorectal cancer, and estrogens and progesterone help prevent bowel cancer from developing; these three hormones also have a relevant role in the cellular and other non-cellular components of the tumor microenvironment of colorectal cancer.

Conclusion

The current literature suggests that androgens, estrogens, and progesterone are valuable in diagnosing and treating colorectal cancer, and that androgens promote the growth of colorectal cancer whereas estrogens and progesterone inhibit colorectal cancer, and that, in addition, the receptors associated with them are implicated in the modulation of a variety of cellular components of the microenvironment of colorectal cancer.

A Metabolomic Signature of Obesity and Risk of Colorectal Cancer: Two Nested Case-Control Studies

Obesity is a leading contributor to colorectal cancer (CRC) risk, but the metabolic mechanisms linking obesity to CRC are not fully understood. We leveraged untargeted metabolomics data from two 1:1 matched, nested case-control studies for CRC, including 223 pairs from the US Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial and 190 pairs from a prospective Chinese cohort. We explored serum metabolites related to body mass index (BMI), constructed a metabolomic signature of obesity, and examined the association between the signature and CRC risk. In total, 72 of 278 named metabolites were correlated with BMI after multiple testing corrections (p FDR < 0.05). The metabolomic signature was calculated by including 39 metabolites that were independently associated with BMI. There was a linear positive association between the signature and CRC risk in both cohorts (p for linear < 0.05). Per 1-SD increment of the signature was associated with 38% (95% CI: 9-75%) and 28% (95% CI: 2-62%) higher risks of CRC in the US and Chinese cohorts, respectively. In conclusion, we identified a metabolomic signature for obesity and demonstrated the association between the signature and CRC risk. The findings offer new insights into the underlying mechanisms of CRC, which is critical for improved CRC prevention.

Sex disparities in the incidence of 21 cancer types: Quantification of the contribution of risk factors

BACKGROUND

Cancer incidence is higher in men than in women at most shared anatomic sites for currently unknown reasons. The authors quantified the extent to which behaviors (smoking and alcohol use), anthropometrics (body mass index and height), lifestyles (physical activity, diet, medications), and medical history collectively explain the male predominance of risk at 21 shared cancer sites.

METHODS

Prospective cohort analyses (n = 171,274 male and n = 122,826 female participants; age range, 50-71 years) in the National Institutes of Health-AARP Diet and Health Study (1995-2011). Cancer-specific Cox regression models were used to estimate male-to-female hazard ratios (HRs). The degree to which risk factors explained the observed male-female risk disparity was quantified using the Peters-Belson method.

RESULTS

There were 26,693 incident cancers (17,951 in men and 8742 in women). Incidence was significantly lower in men than in women only for thyroid and gallbladder cancers. At most other anatomic sites, the risks were higher in men than in women (adjusted HR range, 1.3-10.8), with the strongest increases for bladder cancer (HR, 3.33; 95% confidence interval [CI], 2.93-3.79), gastric cardia cancer (HR, 3.49; 95% CI, 2.26-5.37), larynx cancer (HR, 3.53; 95% CI, 2.46-5.06), and esophageal adenocarcinoma (HR, 10.80; 95% CI, 7.33-15.90). Risk factors explained a statistically significant (nonzero) proportion of the observed male excess for esophageal adenocarcinoma and cancers of liver, other biliary tract, bladder, skin, colon, rectum, and lung. However, only a modest proportion of the male excess was explained by risk factors (ranging from 50% for lung cancer to 11% for esophageal adenocarcinoma).

CONCLUSIONS

Men have a higher risk of cancer than women at most shared anatomic sites. Such male predominance is largely unexplained by risk factors, underscoring a role for sex-related biologic factors.

Plasma sex hormones and risk of conventional and serrated precursors of colorectal cancer in postmenopausal women

BACKGROUND

Sex hormones have been suggested to play a role in colorectal cancer (CRC), but their influence on early initiation of CRC remains unknown.

METHODS

We retrospectively examined the associations with risk of CRC precursors, including conventional adenomas and serrated polyps, for plasma estrone, estradiol, free estradiol, testosterone, free testosterone, sex hormone-binding globulin (SHBG), and the ratio of estradiol to testosterone among 5404 postmenopausal women from the Nurses' Health Study I and II. Multivariable logistic regression was used to calculate the odds ratio (OR) and 95% confidence intervals (CI). Given multiple testing, P < 0.005 was considered statistically significant.

RESULTS

During 20 years of follow-up, we documented 535 conventional adenoma cases and 402 serrated polyp cases. Higher concentrations of SHBG were associated with lower risk of conventional adenomas, particularly advanced adenomas (multivariable OR comparing the highest to the lowest quartile, 0.40, 95% CI 0.24-0.67, P for trend < 0.0001). A nominally significant association was found for SHBG with lower risk of large serrated polyps (≥ 10 mm) (OR, 0.47, 95% CI 0.17-1.35, P for trend = 0.02) as well as free estradiol and free testosterone with higher risk of conventional adenomas (OR, 1.54, 95% CI 1.02-2.31, P for trend = 0.03 and OR, 1.33, 95% CI 0.99-1.78, P for trend = 0.03, respectively).

CONCLUSIONS

The findings suggest a potential role of sex hormones, particularly SHBG, in early colorectal carcinogenesis.

Hormonal and reproductive factors and risk of upper gastrointestinal cancers in men: A prospective cohort study within the UK Biobank

Incidence of upper gastrointestinal cancers of the oesophagus and stomach show a strong unexplained male predominance. Hormonal and reproductive factors have been associated with upper gastrointestinal cancers in women but there is little available data on men. To investigate this, we included 219,425 men enrolled in the UK Biobank in 2006-2010. Baseline assessments provided information on hormonal and reproductive factors (specifically hair baldness, number of children fathered, relative age at first facial hair and relative age voice broke) and incident oesophageal or gastric cancers were identified through linkage to U.K. cancer registries. Unadjusted and adjusted hazard ratios (HR) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models. During 8 years of follow-up, 309 oesophageal 210 gastric cancers occurred. There was some evidence that male pattern baldness, was associated with gastric cancer risk (adjusted HR 1.35, 95% CI 0.97, 1.88), particularly for frontal male pattern baldness (adjusted HR 1.52, 95% CI 1.02, 2.28). There was little evidence of association between other hormonal and reproductive factors and risk of oesophageal or gastric cancer, overall or by histological subtype. In the first study of a range of male hormonal and reproductive factors and gastric cancer, there was a suggestion that male pattern baldness, often used as a proxy of sex hormone levels, may be associated with gastric cancer. Future prospective studies that directly test circulating sex steroid hormone levels in relation to upper gastrointestinal cancer risk are warranted.

Whole exome sequencing and single nucleotide polymorphism array analyses to identify germline alterations in genes associated with testosterone metabolism in a patient with androgen insensitivity syndrome and early-onset colorectal cancer

Background

Androgen insensitivity syndrome (AIS), a disorder of sexual development in 46, XY individuals, is caused by loss-of-function mutations in the androgen receptor (AR) gene. A variety of tumors have been reported in association with AIS, but no cases with colorectal cancer (CRC) have been described.

Case presentation

Here, we present a male patient with AIS who developed multiple early-onset CRCs and his pedigree. His first cousin was diagnosed with AIS and harbored the same AR gene mutation, but with no signs of CRC. The difference in clinical management for the two patients was that testosterone treatment was given to the proband for a much longer time compared with the cousin. The CRC family history was negative, and no germline mutations in well-known CRC-related genes were identified. A single nucleotide polymorphism array revealed a microduplication on chromosome 22q11.22 that encompassed a microRNA potentially related to CRC pathogenesis. In the proband, whole exome sequencing identified a polymorphism in an oncogene and 13 rare loss-of-function variants, of which two were in CRC-related genes and four were in genes associated with other human cancers.

Conclusions

By pathway analysis, all inherited germline genetic events were connected in a unique network whose alteration in the proband, together with continuous testosterone stimulation, may have played a role in CRC pathogenesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s40880-016-0115-1) contains supplementary material, which is available to authorized users.

The Regulation of Steroid Action by Sulfation and Desulfation

Steroid sulfation and desulfation are fundamental pathways vital for a functional vertebrate endocrine system. After biosynthesis, hydrophobic steroids are sulfated to expedite circulatory transit. Target cells express transmembrane organic anion-transporting polypeptides that facilitate cellular uptake of sulfated steroids. Once intracellular, sulfatases hydrolyze these steroid sulfate esters to their unconjugated, and usually active, forms. Because most steroids can be sulfated, including cholesterol, pregnenolone, dehydroepiandrosterone, and estrone, understanding the function, tissue distribution, and regulation of sulfation and desulfation processes provides significant insights into normal endocrine function. Not surprisingly, dysregulation of these pathways is associated with numerous pathologies, including steroid-dependent cancers, polycystic ovary syndrome, and X-linked ichthyosis. Here we provide a comprehensive examination of our current knowledge of endocrine-related sulfation and desulfation pathways. We describe the interplay between sulfatases and sulfotransferases, showing how their expression and regulation influences steroid action. Furthermore, we address the role that organic anion-transporting polypeptides play in regulating intracellular steroid concentrations and how their expression patterns influence many pathologies, especially cancer. Finally, the recent advances in pharmacologically targeting steroidogenic pathways will be examined.

Plasma testosterone in the general population, cancer prognosis and cancer risk: a prospective cohort study

BACKGROUND

Testosterone is an important anabolic hormone in humans and in vitro testosterone stimulates growth of lung and colon cancer cells. We tested the hypothesis that plasma testosterone associate with increased risk of cancer and with increased risk of early death after cancer.

MATERIALS AND METHODS

Plasma testosterone was measured in 8771 20- to 94-year-old men and women who participated in a prospective study of the general population. Participants were included in 1981-1983 and followed for a median of 22 years (range: 0-30 years).

RESULTS

During follow-up, 1140 men and 809 women developed cancer. For risk of early death after cancer, for men, after adjustment for age at diagnosis, tumour stage at diagnosis, and time since blood-sampling, the hazard ratio was 1.30 [95% confidence interval (CI) 1.03-1.65] for the 2nd quintile, 1.31 (1.02-1.67) for the 3rd quintile, 1.52 (1.19-1.93) for the 4th quintile, and 1.52 (1.20-1.91) for the 5th quintile, versus the 1st quintile. For women, corresponding hazard ratios were 1.09 (0.81-1.46), 1.17 (0.86-1.59), 1.03 (0.76-1.39), and 1.80 (1.32-2.46). For risk of cancer, multifactorially adjusted hazard ratios for risk of any cancer were 1.07 (95% CI 0.98-1.18) and 1.06 (0.93-1.22) for men and women, respectively, when testosterone doubled. For both men and women, a doubling of testosterone was not associated with risk of any cancer type.

CONCLUSIONS

In this prospective study of 8771 men and women from the general population followed for >30 years, increased levels of testosterone were associated with a 30%-80% increased risk of early death after cancer, but unchanged risk of incident cancer.

Androgen induces ornithine decarboxylase gene expression in colonic cell line HT-29

Carcinoma of the colon is the second most common cancer among men and women combined in the United States.

PURPOSE

Ornithine decarboxylase (ODC) is the first and key regulatory enzyme in the polyamine biosynthesis pathway and is regulated by various factors. Polyamines are believed to participate in cellular proliferation and differentiation. High levels of polyamines and ODC activity are associated with rapid cell growth, particularly in tumor tissues. Regulation of this enzyme in vivo has important clinical implications. In the present study, we used Northern analysis and mobility shift assay to investigate whether ODC gene expression is regulated by androgens in the three human colonic cell lines, SW620, HT-29, and Caco-2.

METHODS

Cell lines were maintained in Dulbecco's Modified Eagle's medium/F12 supplemented with 5 percent fetal bovine serum. At 60 percent confluency, medium was replaced with steroid-depleted medium, and incubation continued for 24 hours. Following this period, medium was replaced with fresh steroid-free medium containing 1 nM dihydrotestosterone.

RESULTS

Dihydrotestosterone stimulated ODC messenger ribonucleic acid expression only in HT-29 colonic cell line. Studies using electrophoretic mobility shift assays of nuclear extracts also showed a binding pattern with SP1 and NF-kappaB regulatory sequences only in testosterone-treated HT-29 cells.

CONCLUSION

These results suggest that androgens may play an important role in the growth of HT-29 colonic cell lines.

Estrogen receptors and polyamine levels in human gastric carcinoma

We evaluated polyamine (putrescine, spermidine, and spermine) levels, estrogen receptor concentrations, and their relationship in neoplastic tissue and surrounding mucosa from 30 patients with gastric adenocarcinoma. Cytosolic estrogen receptors were measured with an immunoenzymatic assay. Polyamine levels were evaluated with high-performance liquid chromatography. Estrogen receptor concentrations were statistically higher in surrounding mucosa than in neoplastic tissue (p = 0.023). Putrescine and spermidine levels and the spermidine to spermine ratio were statistically higher in neoplastic tissue than in surrounding mucosa (p < 0.004). Significant correlations were found between the levels of spermidine and total polyamines in neoplastic tissue and surrounding mucosa (r = 0.48, p = 0.014, and r = 0.45, p = 0.021, respectively). Polyamine levels were lower in estrogen-receptor-positive tumors than in estrogen-receptor-negative ones, although this decrease was statistically significant only in the case of spermine (p = 0.02). The significance of these findings is that the cellular activity of normal and neoplastic gastric mucosa may be partly controlled by estrogens.

Sex steroid hormone receptors, epidermal growth factor receptor, and polyamines in human colorectal cancer

We assayed the estrogen and progesterone cytosolic receptors by using the enzyme immunoassay method, the epidermal growth factor (EGF) cell surface receptors by using 125I-labeled hormone, and the levels of polyamines (putrescine, spermine, and spermidine) by using a high-pressure liquid chromatography (HPLC) procedure in neoplastic and surrounding normal tissues of patients with colorectal cancer. Our findings show that mean polyamine levels in neoplastic tissue were approximately two-fold greater than the levels in normal colonic mucosa. Estrogen and progesterone receptorial content in normal mucosa were twofold greater than those in neoplastic tissue. No significant differences in EGF receptors were found between colonic cancer tissue and the surrounding normal tissues. The correlations we found between 1) estrogen and polyamine levels and 2) estrogen and EGF binding suggest the existence of a modulation of the estrogens on colonic mucosa cell proliferation. Furthermore, there was no significant dependency of polyamine and receptor concentrations from the tumor site, the histologic differentiation, or the age and sex of patients.

Nuclear and cytosolic estrogen receptors in human colon carcinoma and in surrounding noncancerous colonic tissue

The measurement of estrogen as well as progesterone receptors has been applied clinically to predict the effectiveness of endocrine therapy in patients with breast or endometrial carcinoma. The presence of cytosolic estrogen receptors in human colorectal carcinomas has been reported by several different groups during the past 10 yr. The aim of our current study was to evaluate the estrogen binding activity in the nuclear and cytosolic fractions of these carcinomas, as well as in surrounding noncancerous colonic tissue. Twenty-six patients, operated on for colorectal carcinoma, were studied: 16 were men and 10 were postmenopausal women, mean age 61 yr (range 43-78 yr). In neoplastic tissue, cytosolic estradiol receptors were detected in 42.3% of the patients (women 40%, men 43.7%). The values for cytosolic estrogen receptor ranged from 118 to 1214 fmol/g wet colon. Nuclear estrogen receptors were detectable in 46.1% of the patients (women 40%, men 50%) and their values displayed a range from 3.4 to 2554 fmol/g wet colon. In 30.7% of the patients, both nuclear and cytosolic receptors were demonstrated. In 38.4% of the patients, receptors were found in neither cytosol nor nuclei. Receptor positivity in men was most frequently associated with tumors removed from the rectum, and those with Dukes' classification of C1. In the surrounding noncancerous tissue cytosolic estrogen receptors were also detected (range 133-1105 fmol/g wet colon) and were present in 34.6% of the patients (women 30%, men 37.5%). Nuclear estrogen receptors (range 225-1105 fmol/g wet colon) were detected in 57.6% of the patients (women 40%, men 68.7%). In 23% of the patients, both nuclear and cytosolic receptors were demonstrated. In 30.7% of the patients, no receptors were found in either cytosol or nucleus. Therefore, the presence of cytosolic or nuclear estrogen receptors, or both, in 61.6% of human colorectal cancer specimens emphasizes the need to evaluate both forms of these receptors for studies of potential hormone dependence in these tumors.

Androgen receptors in experimentally induced colon carcinogenesis

Sex hormones may play a role in colonic carcinogenesis, as evidenced by epidemiologic and experimental data showing different tumor rates in males and females. We investigated the effects of hormonal manipulation on tumor development and on androgen receptor binding in both colonic wall and experimentally induced tumors in male rats. Five of six groups, each with 40 animals, were given 10 weekly s.c. injections of azoxymethane (AOM), 7.5 mg/kg body weight. Group-I served as normal controls. Group-II received AOM only. Group-III was castrated 2 weeks prior to carcinogen treatment. Group-IV was castrated similarly and then hormone substituted with testosterone propionate. Group-V was chemically castrated with the anti androgen cyproterone acetate. Group-VI was castrated and given hormone vehicle. Scatchard analysis for androgen receptors in cytosol from normal colonic wall and tumor was performed with 3H-methyltrienolone as the ligand. Androgens were found to have an inhibitory effect on carcinogenesis: chemical castration increased colonic tumor development (P less than 0.05 for multiplicity), and testosterone administration produced a borderline statistically significant reduction in tumor incidence in surgically castrated rats (P less than 0.053), particularly in the right colon. Specific binding sites for androgen with high affinity and low capacity were found in the colonic wall of all groups. Receptor density was not altered by AOM administration, but increased after surgical castration. Receptor density was markedly lower in tumors than in normal colonic wall. Receptor binding sites in tumors were not altered by the various hormonal manipulations. Our study demonstrated that although cytoplasmic androgen receptors are present in colonic wall and in experimental tumors, AOM-induced colonic carcinogenesis appears to be only mildly affected by manipulation of androgens.

Androgen receptors in rectal and colonic cancer

To evaluate the potential effect of androgens on human colorectal cancer, the prevalence and concentration of cytosolic androgen receptors were analyzed in 23 rectal and 13 cecal adenocarcinomas by a hybrid radioligand assay. Androgen receptors were detected in nine of the rectal (39 percent) and five of the cecal tumors (38 percent). Androgen receptor levels demonstrated were low, ranging from three to 17 fmol/mg cytosol protein. Dissociation constants were 1 nM or less. The presence of androgen receptors was independent of age or sex of the patient, and of the state of histologic differentiation and Dukes' staging of the tumor. Androgen receptor prevalence was similar in mucosa adjacent to rectal and cecal adenocarcinomas and in mucosa from five of ten patients (50 percent) with diverticular disease. Our findings suggest that androgen dependency does not play a major role in endocrine control of the development of rectal cancer.

Steroid receptors in dimethylhydrazine-induced colon carcinogenesis

To investigate whether gonadal hormones are involved in the tumorigenesis of dimethylhydrazine (DMH)-induced colonic neoplasms, the authors measured steroid receptors in the neoplasms. 30- or 60-day-old BD-IX rats were injected with 20 mg of 1,2-DMH per kg of body weight once a week for 20 weeks. Fifty-seven rats were sacrificed at 40 to 45 weeks after the initial injection. Androgen receptor (AR), estrogen receptor (ER), and progesterone receptor (PR) were measured in colonic neoplasms. The total number of colonic neoplasms was 274 among 57 rats, 65.8% in male rats and 34.2% in female rats. The mean number of colonic neoplasms per rat was higher in male rats, i.e., 5.6, compared with 3.5 in female rats. A slightly higher number of colonic neoplasms per rat was seen in the rats that had the initial injection at 30 days of age. The number of large colonic neoplasms with a diameter of more than 1 cm was 77 (28.1%), 74% of which were seen in male rats. Thus, a higher incidence of tumors that were also larger were seen in male rats. Histologic findings showed that 53.6% of the neoplasms were carcinomas. The highest incidence of colonic neoplasms was in the distal colon in both sexes. Most of the well-differentiated adenocarcinoma were seen in the distal colon (82.2%), whereas mucinous carcinoma and undifferentiated adenocarcinoma were prominent in the proximal colon or cecum (56.1%). In rats with a normal colon, low levels of AR and PR were determined; but ER was not found in any regions of the colon. In DMH-induced colonic cancer, the incidence as well as the concentration was higher in male rats (60.6%, 16.9 +/- 3.6 fm/mg protein), compared with female rats (40.0%, 4.6 +/- 0.8 fm/mg protein). Similar incidences and levels of ER and PR were seen in both sexes. There was no relationship between steroid receptors and histologic findings in colonic neoplasms. These results suggest that the gonadal hormones, especially androgens, appear to be involved in DMH-induced colon tumorigenesis in male rats.

Effects of steroid hormone therapy on primarily xenotransplanted human colorectal adenocarcinomas

Primary xenotransplantation of six different human colorectal adenocarcinomas onto nude mice yielded a mean tumor take of 85%. Administration of steroid hormones induced tumor remissions in some cases. Neither the stage of the original patient's tumors nor their hormone receptor content seemed to be related to the result of the hormone therapies. It is concluded that some colorectal cancers can be treated as hormone-sensitive tumors.