Atefe Abak

BACKGROUND:
miR-221 and miR-222 are homologous miRNAs located in tandem, within 1 kb from each other, on human x chromosome. Recent studies declared that microRNA-222 is aberrantly expressed in various malignancies. The goal of this research was to measure the expression level of has-miR-222-3P and reveal its diagnostic and prognostic importance in breast malignancy.

METHODS:
In this study, 40 pairs of cancerous and matched adjacent non-cancerous breast tissue were collected from patients, and real-time PCR was used to measure the relative expression of miR-222.

RESULTS:
Our study clarified that microRNA-222 is enhanced in tumor tissues in comparison with normal tissue margins (p ≤ 0.05) and overexpression of miR-222 was not associated with clinicopathological factors such as age, BMI, menopausal status, histological type, grade, stage, tumor size, lymph node metastasis (p > 0.05). The receiver operating characteristic (ROC) curve analysis displayed an optimum cutoff point of < 4.17 to prove that miR-222 is a useful biomarker in breast cancer diagnosis.

CONCLUSIONS:
Our findings on miR-222 suggest that it could be a potentially useful target for control and management of breast malignancy.

Cancer progression is a polygenic procedure in which the exosomes can function as substantial roles. Exosomes are tiny, phospholipid bilayer membrane nanovesicles of endocytic derivation with a diameter of 40–100 nm. These nanovesicles can transport bioactive molecules containing mRNAs, proteins, DNA fragments, and non-coding RNAs from a donor cell to recipient cells, and cause the alteration in genetic and epigenetic factors and reprogramming of the target cells. Many diverse cell types such as mesenchymal cells, immune cells, and cancer cells can induce the release of exosomes. Increasing evidence illustrated that the exosomes derived from tumor cells might trigger the tumor initiation, tumor cell growth and progression, metastasis, and drug resistance. The secreted nanovesicles of exosomes can play significant roles in cells communicate via shuttling the nucleic acid molecules and proteins to target cells and tissues. In this review, we discussed multiple mechanisms related to biogenesis, load, and shuttle of the exosomes. Also, we illustrated the diverse roles of exosomes in several types of human cancer development, tumor immunology, angiogenesis, and metastasis. The exosomes may act as the promising biomarkers for the prognosis of various types of cancers which suggested a new pathway for anti-tumor therapeutic of these nanovesicles and promoted exosome-based cancer for clinical diagnostic and remedial procedures.

MicroRNAs are small non-coding RNAs of 18-25 nucleotides that regulate gene expression at the post-transcriptional level through binding to the 3´-UTR of mRNAs and block mRNA transcription or regulate its resistance. Increasing evidence indicates that dysregulation of miRNA is a hallmark of cancer. The miRNAs have an essential role in the regulation of oncogenes or tumor suppressor genes in cell signaling pathways. MiR-221 and miR-222 are two homologous microRNAs, the high expression levels of which have been commonly demonstrated in multiple human cancer types. The miR-221/miR-222 functions have been verifed as oncogenes or tumor suppressors. Here, we reviewed the roles of miR-221/miR-222 in various kinds of cancer progression and development: controlling proliferative signaling pathways, avoiding cell deaths resulted from tumor suppressors, monitoring angiogenesis and even supporting epithelial-mesenchymal transition. We discussed that miR-221/miR-222 act as promising biomarkers for detection of human cancer types and suggested a new pathway for molecular targeted cancer therapy.

Background: miRNA-221 and miRNA-222 are two homologous microRNAs, the high-expression levels of which have been commonly demonstrated in the most current human cancer types as well as breast cancer. The purpose of this research was to determine the clinical value of measuring the expression level of hsa-miR-221-3p in breast cancer tissues and evaluate its biological and prognostic importance in breast cancer (BC).

Methods: A total of 40 tumor samples and matched tumor-free margin specimens were obtained during surgery from patients with BC. After total RNA extraction and cDNA synthesis, the relative expression level of hsa-miR-221-3p in tumor and marginal tissues was examined by quantitative real-time PCR. Moreover, the association between hsa-miR-221-3p expression and clinicopathological features of patients was detected.

Results: The relative expression level of hsa-miR-221-3p in BC tissues was significantly higher than that in adjacent noncancerous breast biopsies (p ≤ 0.0001). Also, there was no significant association between hsa-miR-221-3p expression with clinicopathological characteristics (p > 0.05). The receiver operating characteristic (ROC) curve analyses also represented an optimum cutoff point of < 4.34 to show that hsa-miR-221-3p is an effective molecular biomarker for BC diagnosis.

Conclusions: This study illustrated that analysis of hsa-miR-221-3p relative gene expression may be applied as a biomarker for screening BC patients and could be a substantial tool in diagnosis and prognosis. Also, that could be advantageous in decreasing surgical mistakes in tumor elimination through the surgery and enhancing all over the progression of surgery with reformed tumor clearance.