Table 1 Experimental studies that investigated the role of piRNAs in breast cancer

PiR-36712

Promotes cancer cell proliferation, invasion and migration

Invasive breast ductal carcinoma

In vitro and In vivo

Underexpressed

[79]

PiR-34736

Progression of cell cycle

Invasive breast ductal carcinoma

In vitro

Underexpressed

[82]

PiR-36249

Progression of cell cycle

Invasive breast ductal carcinoma

In vitro

Underexpressed

[82]

PiR-35407

Progression of cell cycle

Invasive breast ductal carcinoma

In vitro

Underexpressed

[82]

PiR-34377

Progression of cell cycle

Invasive breast ductal carcinoma

In vitro

Underexpressed

[82]

PiR-36318

Progression of cell cycle

Invasive breast ductal carcinoma

In vitro

Underexpressed

[82]

PiR-36026

Progression of cell cycle

Invasive breast ductal carcinoma

In vitro

Overexpressed

[82]

PiR-31106

Progression of cell cycle

Invasive breast ductal carcinoma

In vitro

Overexpressed

[82]

PiR-36743

Progression of cell cycle

Invasive breast ductal carcinoma

In vitro

Overexpressed

[82]

PiR-20582

Tumor marker

Invasive breast ductal carcinoma

In vitro

Overexpressed

[83]

PiR-4987

Lymph node positivity

Invasive breast ductal carcinoma

In vitro

Overexpressed

[83]

PiR-20365

Tumor marker

Invasive breast ductal carcinoma

In vitro

Overexpressed

[83]

PiR-20485

Tumor marker

Invasive breast ductal carcinoma

In vitro

Overexpressed

[83]

PiR-651

Tumor progression

Bcap-37 cell line

In vitro

Overexpressed

[39]

PiR-021285

Modulates

Breast cancer invasiveness

MCF7 breast cancer cell lines

In vitro

Overexpressed

[78]

PiR-932

Promotes methylation of Latexin and form immune complexes

Breast cancer stem cells(CSC)

In vitro

Overexpressed

[85]