Peripheral blood mononuclear cells (PBMCs) respond to altered
physiological conditions to alleviate the threat. Production of the 70
kDa heat shock protein (HSP70) is up-regulated to protect proteins from
degradation. Sequestosome-1 (p62) binds to altered proteins and the
p62-protein complex is degraded by autophagy. P62 is also a regulator of
intracellular kinase activity and cell differentiation. We hypothesized
that the PBMC response to a malignant breast mass involves elevated
production of HSP70 and a decrease in intracellular p62. In this study
46 women had their breast mass excised. PBMCs were isolated and
intracellular levels of HSP70 and p62 were quantitated by ELISA.
Differences between women with a benign or malignant breast mass were
determined. A breast malignancy was diagnosed in 38 women (82.6%) while
8 had a benign lesion. Mean intracellular HSP70 levels were 79.3 ng/ml
in PBMCs from women with a malignant lesion as opposed to 44.2 ng/ml in
controls (p = 0.04). The mean PBMC p62 level was 2.3 ng/ml in women with
a benign breast lesion as opposed to 0.6 ng/ml in those with breast
cancer (p < 0.001). Mean p62 levels were lowest in women with invasive
carcinoma and a positive lymph node biopsy when compared to those with
in-situ carcinoma or absence of lymphadenopathy, respectively.
Intracellular HSP70 and p62 levels in PBMCs differ between women with a
malignant or benign breast lesion. These measurements may be of value in
the preoperative triage of women with a breast mass