Background: MicroRNAs (miRNA) belong to the substantial class of posttranscriptional gene regulators with decisive functions in typical cellular and disease progressions. They are short RNA molecules that are not translated into proteins but bind to the complementary sites of various mRNAs, thus blocking them and leading to translational inhibition.

Objective: These miRNA molecules act as signatory molecules or biomarkers for various types of malignancies. Different miRNAs are involved in different cancer-linked pathways depending on the nature, stage, and kind of cancer. The objective of this article is to discuss and review the role and significance of various miRNAs in two of the most prominent cancers; breast and ovarian cancer.

Methods: The role of miRNAs in the instigation, propagation, and metastasis of melanoma has been elucidated.

Results: This article focuses on the up- and down-regulation of various miRNAs in breast and ovarian cancer, with stress on diversity in their occurrence and specificity in their threshold levels in certain types and stages of cancer, suggesting their potential role as an effective diagnostic and treatment tool for cancer.

Conclusion: Considering all the aforementioned information, it can be concluded that miRNAs can act as potential biomarkers for the diagnosis of breast and ovarian cancers.

背景：MicroRNA (miRNA) 属于转录后基因调控因子的重要类别，在典型的细胞和疾病进展中具有决定性功能。它们是短 RNA 分子，不会翻译成蛋白质，而是与各种 mRNA 的互补位点结合，从而阻断它们并导致翻译抑制。

目的：这些 miRNA 分子作为各种类型恶性肿瘤的标志分子或生物标志物。根据癌症的性质、阶段和种类，不同的 miRNA 参与不同的癌症相关途径。本文的目的是讨论和回顾各种 miRNA 在两种最突出的癌症中的作用和意义；乳腺癌和卵巢癌。

方法：已阐明 miRNA 在黑色素瘤的诱发、传播和转移中的作用。

结果：本文重点研究了乳腺癌和卵巢癌中各种 miRNA 的上调和下调，强调了它们在某些癌症类型和阶段中发生的多样性和阈值水平的特异性，表明它们作为一种有效的癌症的诊断和治疗工具。

结论：考虑到上述所有信息，可以得出结论，miRNA 可以作为诊断乳腺癌和卵巢癌的潜在生物标志物。