T. Utsumi

Elevated steroid sulfatase expression in breast cancers

In situ estrogen synthesis makes an important contribution to the high estrogen concentration found in breast cancer tissues. Steroid sulfatase which hydrolyzes several sulfated steroids such as estrone sulfate, dehydroepiandrosterone sulfate, and cholesterol sulfate may be involved. In the present study, we therefore, assessed steroid sulfatase mRNA levels in breast malignancies and background tissues from 38 patients by reverse transcription and polymerase chain reaction. The levels in breast cancer tissues were significantly increased at 1458.4+/-2119.7 attomoles/mg RNA (mean +/- SD) as compared with 535.6+/-663.4 attomoles/mg RNA for non-malignant tissues (P<0.001). Thus, increased steroid sulfatase expression may be partly responsible for local overproduction of estrogen and provide a growth advantage for tumor cells.

Bladder and male sexual functions after autonomic nerve-sparing TME with or without lateral node dissection for rectal cancer

Abstract.Background: We evaluated to what extent lateral lymph node dissection (LND) interferes with bladder and male sexual functions after radical rectal excision with adoption of careful total autonomic nerve preservation. Methods: The study comprised 77 patients resected for mid-rectal or lower rectal cancer. Bladder and male sexual functions were studied by means of a questionnaire more than one year after surgery. Outcomes were compared between patients who received lateral LND (group 1, 65 patients) and those who did not (group 2, 12 patients). Results: Only minor disturbances of bladder function were reported in 10 patients (15%) of group 1, and in 3 patients (25%) of group 2. Ten out of 37 preoperatively sexually active patients (27%) in group 1 males and one of 5 patients (20%) in group 2 males had partial or total impotency after surgery and retrograde ejaculation occurred in 3 of 27 patients (11%) and one of 4 patients (25%), respectively. Erectile impotency occurred less frequently when patients were operated during the period 1993–1996 than during 1988-1992 (11% vs. 42%, p<0.05). The age was significantly greater among patients who had loss of ejaculation. Conclusions: If lateral lymph node dissection should be used with the aim of improving radicality in rectal excision for cancer, it should be combined with careful nerve-preserving technique - which may reduce the risk of bladder and male sexual dysfunctions.

Molecular and epidemiological analyses of abnormal expression of aromatase in breast cancer.

One-third of human breast cancers exhibit estrogen-dependent proliferation. It appears that estrogen functions as a mitogenic factor in these carcinomas. As aromatase is the rate-limiting enzyme in estrogen biosynthesis. It could play an important role in the pathogenesis of estrogen-dependent breast cancer. The aromatase gene consists of at least six exons 1, each containing a promoter, and the tissue-specific expression is regulated by alternative use of these multiple promoters. The expression of aromatase in the breast and abdominal adipose tissues is regulated by a promoter flanking exon 1b. Molecular and epidemiological analyses of tissue-specific utilization of multiple exons 1 and promoters revealed a switching from use of the adipose-specific exon 1b to exon 1c in adipose tissues adjacent to the carcinomas in most breast cancer patients. Exon 1c has been shown to be specific for the ovary. Aromatase mRNA in adipose tissues distal to the tumour of the same patients was normally transcribed from exon 1b as was breast tissue in healthy controls. It is noteworthy that a switching from exon 1b to exon 1c was often observed in breast cancer patients having metastatic lymph nodes. These data suggest that switching from an adipose-specific exon 1b to exon 1c could cause a deviation from strict regulation of tissue-specific expression of the adipose aromatase leading to over-expression of the adipose aromatase. Consequently overproduction of local estrogen may promote carcinogenesis or proliferation of breast cancer cells.

Sex steroid hormones in pairs of tumor and serum from breast cancer patients and pathobiological role of androstene-3β, 17β-diol.

Estrogens play an important role in the pathobiology of breast cancer. In postmenopausal women, peripheral synthesis of estrogens from adrenal/ovarian androgens, dehydroepiandrosterone (DHEA) or androstenedione (Adione), by estrogen‐metabolizing enzymes is important. Besides estrone (E1) and estradiol (E2), androgen metabolites, such as androstene‐3β, 17β‐diol (Aenediol) or 5α‐androstane‐3β, 17β‐diol (Aanediol), are known to have estrogenic functions, although they have been studied much less in breast cancer. To precisely elucidate steroid metabolism in breast cancer patients and to identify the pathobiological role of estrogenic androgen metabolites, concentrations of DHEA, Adione, Aenediol, Aanediol, E1, and E2 in pairs of serum and tumor tissue from patients with primary breast cancer were measured by liquid chromatography‐tandem mass spectrometry. Cell proliferation assays using Aenediol were performed for four breast cancer cell lines. Serous E2 concentration was extremely low in postmenopausal women; however, a marked increase in tumor tissue was observed in hormone receptor‐positive cases. E1 concentration, in contrast, was sustained at a higher level, even in postmenopausal serum, and did not increase in tumor tissue irrespective of the hormone receptor status. Dehydroepiandrosterone was most abundant in all samples, and exhibited a similar pattern as Adione and Aenediol. 5α‐Androstane‐3β, 17β‐diol was undetectable in most samples. Androstene‐3β, 17β‐diol proliferated estrogen receptor‐α‐positive breast cancer cells in the absence of E2. The intratumoral increase of E2, but not E1, in hormone receptor‐positive postmenopausal breast cancer tissue, as well as the proliferative role of Aenediol, was elucidated. (Cancer Sci 2011; 102: 1848–1854)

The effects of 2-methoxyoestrogen sulphamates on the in vitro and in vivo proliferation of breast cancer cells.

2-Methoxyoestrogen sulphamates are a new class of compounds, which inhibit breast cancer cell proliferation and are also potent inhibitors of steroid sulphatase (STS) activity. In the present study, we have used two cell proliferation assays (MTS and AB) to identify potent new compounds in this class. Similar IC(50) values were obtained using these assays with two of the most potent compounds identified being 2-methoxyoestradiol-bis-sulphamate (2-MeOE2bisMATE) and 2-methoxyoestradiol-17beta-cyanomethyl-3-O-sulphamate (2-MeOE2CyMATE). Both compounds inhibited the proliferation of MCF-7 (ER+) and MDA-MB-231 (ER-) breast cancer cells. Using the AB assay, which allows repeat measurements of cell proliferation without killing cells, both compounds were shown to inhibit cell proliferation in an irreversible manner. As STS may be involved in the removal of the sulphamoyl moiety of these compounds, which could reduce their potency, their ability to inhibit the proliferation of MCF-7 cells transfected with the cDNA for STS was also examined. Although the STS activity was 20-fold higher in these cells than in non-transfected MCF-7 cells, no decrease in the ability of these compounds to inhibit cell proliferation was detected. To test the efficacy of these compounds in vivo, nude mice were inoculated with MCF-7 cells in Matrigel and stimulated to grow with oestradiol. Three weeks after the oral administration of 2-MeOE2bisMATE or 2-MeOE2CyMATE (20mg/kg/day, 5 days/week) tumour volumes had regressed by 52% and 22%, respectively. Both compounds also inhibited liver and tumour STS activity by >90%. The potent anti-proliferative effects of these compounds, and their ability to inhibit tumour growth and STS activity in vivo, indicates that they are suitable for development as novel therapeutic agents, which should be active against a wide range of cancers.

Correlation of cyclin D1 mRNA levels with clinico-pathological parameters and clinical outcome in human breast carcinomas

In order to evaluate the prognostic significance of cyclin D1 mRNA expression in mammary neoplasia, its levels were measured in 97 breast cancers by reverse transcription‐polymerase chain reaction (PCR) using fluorescent primer and standard RNA along with estrogen receptor (ER). The median value of cyclin D1 mRNA was 1.60 amol/μg RNA (range, 0.01 to 5.63 amol/μg RNA). ER mRNA was detectable in 70 breast cancer samples (72.2%) and cyclin D1 mRNA levels were significantly higher in ER mRNA‐positive than in ER mRNA‐negative tumors (p = 0.009). Furthermore, cyclin D1 mRNA levels were significantly (p = 0.001) lower in patients who experienced a recurrence during the follow‐up period (mean of 40.8 months, median of 39 months) compared with those with no evidence of recurrent disease (mean of 49.2 months, median of 48 months), and in those who died from disease (mean follow‐up period of 30.5 months, median of 26 months) than in the survivors (mean of 50.5 months and median of 48 months) (p = 0.005). Setting the median value (=1.60 amol/μg RNA) as the cutoff point, expression was significantly associated with relapse‐free survival (p = 0.002). Similarly, a significant correlation was observed between the cyclin D1 mRNA level and overall survival (p = 0.015). The expression was found to be an independent factor for predicting relapse‐free survival using multivariate analysis. Int. J. Cancer (Pred. Oncol.) 89:39–43, 2000.

Expression level of enzymes related to in situ estrogen synthesis and clinicopathological parameters in breast cancer patients

In order to evaluate the importance of estrogen production in tumor and surrounding tissues, we measured mRNA expression levels of 5 enzymes participating to estrogen synthesis in situ and 4 breast cancer-related proteins in 27 pairs of tumor and non-malignant tissues. Steroid sulfatase (STS) mRNA was more frequently detected in tumor tissues rather than in their non-malignant counterparts. Estrogen sulfotransferase (EST) was constantly expressed with high level not only in tumor tissues but also in their surrounding non-malignant counterparts. In contrast, mRNA expression levels of aromatase, and 17beta-hydroxysteroid dehydrogenase type I and II were relatively low and detected only in small proportion of the patients. We also measured the mRNA expression levels of the same nine genes in tumor tissues of 197 breast cancer patients, and analyzed relationship between the mRNA expression level and the clinicopathological parameters. The mRNA expression levels of STS, aromatase and erbB2 in tumor tissues increased as breast cancer progressed. The tumoral mRNA expression levels of STS, estrogen receptor beta, and erbB2 in patients with recurrence were higher than those in patients without recurrence. Upregulation of STS expression plays an important role in tumor progression of human breast cancer and is considered to be responsible for estrogen production in tumor and surrounding tissues.

Local correction of a transverse loop colostomy prolapse by means of a stapler device

Abstract.Prolapse is a common complication in patients with a transverse loop colostomy. In most cases, the prolapse can be managed conservatively awaiting time for closure eventually. However, loop stoma may also be intentionally permanent or the patient may be too fragile to have the colostomy closed and in these cases a laparotomy is required for correction of the prolpase. A simple method allowing local correction of the prolapsed loop stoma is described.

Pathophysiology and prevention of loop stomal prolapse in the transverse colon

Abstract.We investigated both pathogenesis and prevention of loop transverse stomal prolapse. Seven patients with reducible prolapsed stoma were studied under fluoroscopy after staining the prolapsed stoma and the colon by barium medium while prolapsing or reducing the stoma with or without the stomal wall pressed on to the abdominal wall of fascial plane. All prolapses occurred in the distal limbs of the loop stoma with the distal transverse colons redundant. The prolapse started around the mucocutaneous suture with the stoma inflated and the colon in it depressed and proceeded in accordance with an addition of abdominal pressure, but did not occur by pressing of the stomal wall. Prolapse of transverse loop stoma occurs when redundant colon invades the stoma with an abdominal pressure. Stomal prolapse might be prevented by fixation of the colon to the fascia.

Significance of steroid sulfatase expression in human breast cancer

The sulfatase pathway has been thought to be a primary means of local production of estrone in human breast cancer tissue. We measured steroid sulfatase (STS) mRNA levels in 97 breast cancers and evaluated its association with disease-free survival. High levels of STS mRNA proved to be a significant predictor of reduced relapse-free survival, both as a continuous variable (log STS mRNA; P=0.028) and as a dichotomous variable with an optimized cutoff point (P=0.002). In multivariate analysis a high level of STS mRNA was an independent factor for predicting relapse-free survival. These results suggest a putative role of STS in breast cancer growth and metastasis, and administration of sulfatase inhibitors to breast cancer patients with high levels of STS mRNA might be an additional treatment option.