Gene and protein expression of p53 and p21 in fibroadenomas and adjacent normal mammary tissue

Association analyses of a genetic variant in long non-coding RNA MEG3 with breast cancer susceptibility and serum MEG3 expression level in the Egyptian population

BACKGROUND

LncRNA MEG3 rs7158663 has been shown to confer cancer susceptibility, maybe through altering its gene expression level.

OBJECTIVE

We aimed to weigh the effect of rs7158663 on MEG3 serum level and breast cancer susceptibility.

METHODS

We genotyped rs7158663 G > A and measured serum MEG3 in 150 breast cancer, 95 fibroadenoma , and 154 controls by the TaqMan method.

RESULTS

The presence of rs7158663 G > A is a risk factor for breast cancer among fibroadenoma patients and controls, AA vs. GG genotypes (OR = 6.320, 95% CI = 2.587-15.439, P< 0.0001 when compared to controls and OR = 10.825, 95% CI = 1.929-60.742, P= 0.007 when compared to fibroadenoma). Decreased serum MEG3 was observed in breast cancer group when compared with fibroadenoma and/or controls [median (IQR) = 0.43 (0.27-0.55)] (P< 0.0001). However, increased serum MEG3 was noted in fibroadenoma group when compared with controls (P< 0.0001). A significance decreased serum MEG3 was found to be associated with mutant A allele than with wild G allele (P< 0.0001). The results showed that rs7158663 and lower MEG3 were significantly associated with patients with higher TNM staging and larger tumor size > 5 cm.

CONCLUSION

The presence of both rs7158663 and low MEG3 are diagnostic and unfavorable prognostic factors for BC patients.

Genetics and genomics of breast fibroadenomas

Fibroadenomas of the breast are benign fibroepithelial tumours most frequently encountered in women of reproductive age, although they may be diagnosed at any age. The fibroadenoma comprises a proliferation of both stromal and epithelial components. The mechanisms underlying fibroadenoma pathogenesis remain incompletely understood. In the clinical setting, distinguishing cellular fibroadenomas from benign phyllodes tumours is a common diagnostic challenge due to subjective histopathological criteria and interobserver differences. Recent sequencing studies have demonstrated the presence of highly recurrent mutations in fibroadenomas, and also delineated the genomic landscapes of fibroadenomas and the closely related phyllodes tumours, revealing differences at the gene level, which may be of potential adjunctive diagnostic use. The present article provides an overview of key studies uncovering genetic and genomic abnormalities in fibroadenomas, from initial karyotype reports revealing myriad cytogenetic aberrations to next-generation sequencing-based approaches that led to the discovery of highly recurrent MED12 mutations. A thorough understanding of these abnormalities is important to further elucidate the mechanisms by which fibroadenomas arise and to refine diagnostic assessment of this very common tumour.

Protein expression of estrogen receptors α and β and aromatase in myometrium and uterine leiomyoma

BACKGROUND

Leiomyomas are the most common tumors of the female reproductive tract and a major public health problem. The mechanism of tumorigenesis is unknown, but evidence suggests that estrogens regulate cell proliferation and myoma growth. This effect might be due to different amounts of estrogen receptors (ERα and ERβ) in normal and myoma tissues and overexpression of aromatase P450 in myomas.

PURPOSE

To assess protein expression of ERs and aromatase in leiomyomas and normal adjacent myometrium of premenopausal women.

METHODS

Samples were collected from 12 premenopausal women admitted for abdominal hysterectomy due to fibroids.

RESULTS

The protein expression of ERα, ERβ and aromatase was similar in leiomyoma and normal myometrium (p = 0.239, p = 0.695 and p = 0.203, respectively).

CONCLUSIONS

In this analysis of 12 matched leiomyoma and myometrial samples, the data do not support the theory that overexpression ERα, ERβ and aromatase in uterine leiomyomas compared to adjacent myometrium are the cause of tumor growth. The estrogens may exert their growth-stimulatory effects on leiomyomas intermediated by other elements, such as cytokines and growth or apoptosis factors. The effect of estrogen on the growth and development of fibroids is complex and far from being completely understood.

Gene and protein expression of progesterone receptor isoforms A and B, p53 and p21 in myometrium and uterine leiomyoma

PURPOSE

To assess gene and protein expression of progesterone receptor isoforms A and B, cell cycle regulators p53 and p21 in leiomyoma and myometrium.

METHODS

Samples were collected from 14 patients in reproductive age who underwent abdominal hysterectomy. Gene expression of PRA, PRB, p53 and p21 was analyzed by real-time PCR. Protein expression was assessed by Western blots.

RESULTS

There was no change in gene and protein expression of PRA and PRB in both tissues. The ratio between isoforms (PRA:PRB) was not different between tissues and showed a strong correlation (r = 0.767, P = 0.004). The analysis of gene expression and protein showed increased levels of mRNA and protein p53 in leiomyoma compared to myometrium (P = 0.030 and P = 0.002, respectively). The same increase was observed in p21 mRNA levels (P = 0.016) and protein p21 levels (P = 0.026) in samples of uterine leiomyoma.

CONCLUSIONS

PRA:PRB ratio is similar in normal myometrium and leiomyomas. p53 and p21 mRNA and protein levels are increased in leiomyomas.

Progesterone receptors A and B and estrogen receptor alpha expression in normal breast tissue and fibroadenomas

Fibroadenomas are the most common benign breast tumors, occurring mainly in young women. Their responses to the hormonal environment are similar to those of normal breast tissue, which suggests that steroid receptors may play a role in tumor development. We evaluated the gene and protein expression of progesterone receptors A and B (PRA and PRB) and the protein expression of estrogen receptor alpha (ER-alpha) in fibroadenoma samples, comparing with adjacent normal breast tissue, from 11 premenopausal women. Progesterone and estradiol levels were determined. No alterations in the PRs gene and protein expression and the ER-alpha protein expression were observed between the follicular and luteal phases, in normal breast versus fibroadenomas. Protein levels of PRA and PRB were higher in fibroadenomas compared to normal breast tissue (P = 0.038 and P = 0.031), while the PRs mRNA levels were similar in both tissues (P = 0.721 and P = 0.139). There were no differences in ER-alpha protein expression between normal breast tissue and fibroadenomas (P = 0.508). The PRA:PRB ratio was similar in the tissues, and also showed a strong correlation in both (r = 0.964, P = 0.0001). Our data suggest a role of PRs in the growth and development of fibroadenomas, although without alterations of the PRA:PRB ratio in these tumors. The absence of alterations in ER-alpha protein levels could be a characteristic behavior of fibroadenomas, unlike breast cancer.