Effect of treatment with LHRH analogue Zoladex on binding of oestradiol, progesterone and epidermal growth factor to uterine fibromyomata

A comparative study of the effect of raloxifene and gosereline on uterine leiomyoma volume changes and estrogen receptor, progesterone receptor, bcl-2 and p53 expression immunohistochemically in premenopausal women

OBJECTIVE

To compare the mechanism of action of raloxifene and gosereline induced shrinkage of leiomyomas via estrogen receptor, progesterone receptor, bcl-2 and p53 expression immunohistochemically.

STUDY DESIGN

Thirty-two premenopausal women affected by uterine leiomyomas were randomized into two equal groups. Group A was treated with gosereline (3.6 mg subcutaneous injection monthly) and group B was treated with raloxifene (60 mg daily per os) for 3 months before undergoing surgery. At entry and at the end of the treatment the leiomyoma volume was measured ultrasonografically and the volume change was calculated. Immunohistochemical detection of estrogen receptor (ER), progesterone receptor (PR), bcl-2 and p53 were performed on leiomyoma tissue samples from group A, group B and the matched-control group. H-scores for ER, PR, bcl-2 and p53 were calculated. The mean volume changes of leiomyomas and immunohistochemical H-score differences of ER, PR, bcl-2 and p53 were compared between groups.

RESULTS

The leiomyoma volume decreased significantly after treatment in gosereline group from baseline of 65 cm(3) to 35 cm(3), and in raloxifene group from 68 cm(3) to 50 cm(3), p<0.05. The difference between the before and after treatment leiomyoma volumes between the two treatments was not statistically significant. H-score of ER expression was significantly lower in gosereline group compared to control group (54.4 versus 113.2, p = 0.001), whereas H-score of PR expression was significantly lower with both gosereline and raloxifene groups compared to control group (64.8 for gosereline versus 94.6 for control, 73.6 for raloxifene versus 94.6 for control, p = 0.001). The bcl-2 expression was higher in both gosereline and raloxifene groups compared to control group (173.7 for gosereline versus 94.7 for control, 179.7 for raloxifene versus 94.7 for control, p = 0.001). The p53 expression was only lower with gosereline than the control group (169.4 versus 205.6, p = 0.001), whereas there was no significant change between the raloxifene group and the control group (201.9 versus 205.6) (p>0.05).

CONCLUSION

Raloxifene was as effective as gosereline in reducing leiomyoma volumes. Decreased PR expression may be a mechanism for tumor growth reduction in raloxifene treatment. In both treatment modalities, the mechanism of shrinkage of leiomyomas could not be increased apoptosis mediated by bcl-2 and p53 expression and should be investigated by further studies.

Increased expression of cyclin G1 in leiomyoma compared with normal myometrium

OBJECTIVE

The purpose of this study was to detect the expression of cyclin G1 in leiomyoma and to investigate the alteration of its expression compared with normal myometrial tissue that was obtained from the same patient.

STUDY DESIGN

With the use of Northern blot analysis, Western blot analysis, and immunohistochemistry, we analyzed the expression of cyclin G1 in 24 patients who underwent hysterectomies.

RESULTS

We found that messenger RNA levels of cyclin G1 were elevated in human leiomyomas compared with their adjacent normal myometrial tissues. Consistent with elevated messenger RNA levels, high levels of cyclin G1 protein expression were detected by immunoblot analysis in all leiomyoma samples. Immunohistochemistry revealed that cyclin G1 is located mainly in the nucleus in both normal myometrium and leiomyoma. However, higher levels of cyclin G1 were apparent in tumor regions compared with adjacent normal myometrial regions. In addition, we found the expression levels of other cyclins (A and E) and CDK2 were elevated in leiomyomas compared with normal myometrium. Because cyclin G1 is a transcriptional target of the p53 tumor suppressor, we examined the p53 status of all eight leiomyoma samples and found no p53 mutations.

CONCLUSION

These results suggest that cyclin G1 is frequently overexpressed in uterine leiomyoma in a p53-independent manner and that this abnormality could be attributed to the severe proliferation of human uterine leiomyomas.

Allelotype of uterine leiomyomas

Uterine leiomyomas are the most common benign tumor that arise from smooth muscle cells of the myometrium. Little is known about the etiology and pathogenesis of this tumor. To investigate the molecular pathogenesis of these tumors, we have conducted an allelotype of 102 leiomyomas from 12 patients, using 67 fluorescently-tagged oligonucleotide primers amplifying microsatellite loci covering all autosomes. No areas of the genome showed frequent loss of heterozygosity (LOH); however, the highest rate of LOH (9%) was observed on 7q, consistent with previous cytogenetic observations. Uterine leiomyomas are sometimes multiple. In general, multiplicity of other types of neoplasm is associated with genetic predisposition to the disease. Because multiple tumors were available from each of the 12 patients studied, we looked for evidence of allele-specific LOH, which might indicate the presence of an underlying predisposition gene. However, no evidence for allele-specific LOH was detected, indicating that if cases of multiple uterine leiomyoma are due to an underlying predisposition gene, it is unlikely to be a recessive oncogene.

Analysis of genetic alterations in uterine leiomyomas and leiomyosarcomas by comparative genomic hybridization

Uterine leiomyomas are the most prevalent tumor type in women of reproductive age and are the most common reason for hysterectomies. Although uterine leiomyomas are considered to be benign, they are a major public health concern for women. In contrast, leiomyosarcomas are rare but highly malignant uterine tumors. They may arise in uteri with preexisting leiomyomas and histologically sometimes resemble leiomyomas, thus causing controversy about whether leiomyosarcomas arise within leiomyomas. In this study, we used comparative genomic hybridization (CGH) to identify genetic alterations unique to each tumor type and alterations that are common between the two tumors. We analyzed 14 cases of uterine leiomyomas and eight cases of uterine leiomyosarcomas. Only two of the 14 leiomyomas exhibited genetic alterations, and those were restricted to gains on chromosomes 14 and 19 and losses on chromosomes 1 and 4. In addition, 68 leiomyomas were examined for loss of heterozygosity on chromosomes 1 and 4, and only three tumors exhibited any losses. In contrast, all eight leiomyosarcomas showed gains and losses of DNA by CGH, and in many cases multiple changes were observed. The most commonly observed genetic aberration, occurring in five tumors, was gains on both arms of chromosome 1, suggesting that this chromosome contains loci involved in the development of leiomyosarcoma. Our results do not provide evidence for the progression from benign leiomyoma to malignant leiomyosarcoma. Moreover, the large number of random chromosomal alterations in the leiomyosarcomas suggests that increased genetic instability plays a role in the formation of these tumors.

Progesterone receptor messenger ribonucleic acid and protein are overexpressed in human uterine leiomyomas

OBJECTIVE

Our purpose was to identify molecular mechanisms underlying abnormal growth of uterine leiomyomas.

STUDY DESIGN

Biopsy samples of tumor and adjacent "normal" myometrium from nine patients were analyzed for progesterone receptor gene expression and for proliferation-associated antigen Ki-67.

RESULTS

Northern analysis indicated that progesterone receptor messenger ribonucleic acid levels were increased twofold to 15-fold in leiomyoma compared with adjacent myometrial biopsy tissue from all patients (n = 9), whereas beta-actin messenger ribonucleic acid was at similar levels in these samples. Quantitative immunoassay, immunohistochemistry studies, and Western blot analyses revealed increased amounts of progesterone receptor protein in the tumor tissue. Both the progesterone receptor A and B forms were expressed in the leiomyoma and adjacent myometrium. Corresponding to increased progesterone receptor gene expression, the proliferation-associated antigen Ki-67 was also significantly elevated in the leiomyoma tissue.

CONCLUSION

These data provide the first evidence that progesterone receptor messenger ribonucleic acid is overexpressed in uterine leiomyomas, suggesting that amplified progesterone-mediated signaling is instrumental in the abnormal growth of these tumors.

Sequential Gn-RH superagonist and medroxyprogesterone acetate treatment of uterine leiomyomata

A group of 48 women with symptomatic leiomyomata were treated during 6 months with the short-acting Gn-RH superagonist analog buserelin. The first (group C) was followed up for an additional six months of no medication. The second (group M) was treated for 6 additional months with medroxyprogesterone acetate (MPA) at doses decreasing from 200 to 25 mg/day. Buserelin therapy significantly decreased uterine size (P less than 0.001) in all patients, the average final volume being 48.5% of the original (from 262 +/- 147 ml to 127 +/- 85.4 ml). In group C there was a significant (P less than 0.001) re-growth during the post-treatment observation period (from 120 +/- 81.0 ml to 198 +/- 77.2 ml); a significant (P less than 0.01) re-growth was also observed in group M during MPA medication (from 132 +/- 77.2 ml to 170 +/- 96.0 ml). The agonist had also a marked effect on fibroids: on average they decreased from 75.1 +/- 74.3 ml to 24.7 +/- 23.3 ml (P less than 0.025). In group C during the post-buserelin period of observation without treatment, there was a significant re-growth from 23.7 +/- 21.6 ml to 47.7 +/- 27.5 ml (P less than 0.001), whereas in group M treatment with MPA prevented any significant re-growth (from 25.6 +/- 24.8 to 30.6 +/- 32.9 ml; P greater than 0.3).