From a Medicinal Mushroom Blend a Direct Anticancer Effect on Triple-Negative Breast Cancer: A Preclinical Study on Lung Metastases

Abstract

Bioactive metabolites isolated from medicinal mushrooms (MM) used as supportive treatment in conventional oncology have recently gained interest. Acting as anticancer agents, they interfere with tumor cells and microenvironment (TME), disturbing cancer development/progression. Nonetheless, their action mechanisms still need to be elucidated. Recently, using a 4T1 triple-negative mouse BC model, we demonstrated that supplementation with Micotherapy U-Care, a MM blend, produced a striking reduction of lung metastases density/number, paralleled by decreased inflammation and oxidative stress both in TME and metastases, together with QoL amelioration. We hypothesized that these effects could be due to either a direct anticancer effect and/or to a secondary/indirect impact of Micotherapy U-Care on systemic inflammation/immunomodulation. To address this question, we presently focused on apoptosis/proliferation, investigating specific molecules, i.e., PARP1, p53, BAX, Bcl2, and PCNA, whose critical role in BC is well recognized. We revealed that Micotherapy U-Care is effective to influence balance between cell death and proliferation, which appeared strictly interconnected and inversely related (p53/Bax vs. Bcl2/PARP1/PCNA expression trends). MM blend displayed a direct effect, with different efficacy extent on cancer cells and TME, forcing tumor cells to apoptosis. Yet again, this study supports the potential of MM extracts, as adjuvant supplement in the TNBC management.

Keywords: apoptosis; breast cancer; complementary medicine; in vivo; lung metastases; medicinal mushrooms.

Figure 1

Graphic illustration underlining the main results.

Figure 2

Terminal deoxynucleotidyl-transferase (TUNEL) immunostaining in healthy control (a), 4T1 M. U-care (b,c) and 4T1 (d–g) mice. Light microscopy magnification: 40× (a–c,f,g); 100× (d,e, insert in panels (b,c,g)). Panel (A) and (B): Histograms presenting immunopositive cell density and OD, respectively. p values calculated by unpaired Student’s t-test: (***) < 0.001.

Figure 3

Immunostaining reaction for PARP1 in healthy control (a), 4T1 M. U-care (b,c) and 4T1 (d–g) mice. Light microscopy magnification: 40× (a–c,f,g); 100× (d,e, insert in panel (b)). Panels (A) and (B): Histograms displaying immunopositive cell density and OD, respectively. p values calculated by Unpaired Student’s t-test: (*) < 0.05 and (**) < 0.01.

Figure 4

p53-immunostaining reaction in healthy control (a), 4T1 M. U-care (b,c) and 4T1 (d–g) mice. Light microscopy magnification: 40× (a–c,f,g); 100× (d,e, insert in panels (b,c)). Panels (A) and (B): Histograms showing immunopositive cell density and OD, respectively. p values calculated by Unpaired Student’s t-test: (*) < 0.05 and (**) < 0.01.

Figure 5

Immunohistochemical staining for Bax in healthy control (a), 4T1 M. U-care (b,c) and 4T1 (d–g) mice. Light microscopy magnification: 40× (a–c,f,g); 100× (d,e, insert in panels (b,c)). Panels (A) and (B): Histograms showing immunopositive cell density and OD, respectively. p values calculated by Unpaired Student’s t-test: (*) < 0.05 and (***) < 0.001.

Figure 6

Bcl2-immunostaining reaction in healthy control (a), 4T1 M. U-care (b,c) and 4T1 (d–g) mice. Light microscopy magnification: 40× (a–c,f,g); 100× (d,e). Panels (A) and (B): Histograms showing immunopositive cell density and OD, respectively. p values calculated by Unpaired Student’s t-test: (**) < 0.01.

Figure 7

DAB-immunostaining reaction for PCNA in healthy control (a) 4T1 M. U-care (b,c), and 4T1 (d–g) mice. Light microscopy magnification: 40× (a–c,f,g); 100× (d,e, insert in panel (f)). Panels (A) and (B): Histograms showing immunopositive cell density. Panels (C) and (D): histograms exhibiting immunoreactive OD. p values calculated by Unpaired Student’s t-test: (***) < 0.001.