Tumor Growth Ameliorates Cardiac Dysfunction

Figures

• 

  Figure 1. Tumor growth imposes a cardiac beneficial phenotype following TAC-operation in female mice. (A). Schematic diagram of the experimental timeline. (B). The fractional shortening (FS; right) of TAC-operated, PyMT-bearing (n = 11) and non-cancer-bearing mice (n = 11), calculated from the respective echocardiography data (left). Calculated based on parameters in Supplementary Table S2. (C). Representative images of the hearts of a TAC-operated, PyMT-bearing and non-cancer-bearing mice at endpoint (25 days after PyMT injection). (D). The ventricular weight/body weight ratio (VW/BW mg/gr) of TAC-operated, PyMT-bearing (n = 16) and non-cancer-bearing mice (n = 14). (E). Level of the hypertrophic hallmark gene marker BNP measured using qRT-PCR with cDNA derived from heart mRNA of TAC-operated, PyMT-bearing (n = 8) and non-cancer-bearing mice (n = 8), normalized to the GAPDH housekeeping gene. The results are presented as mean ± SEM, Student’s t-test ** p < 0.01, *** p < 0.001, **** p < 0.0001. In (B,D,E), each dot represents one mouse.

• 

  Figure 2. Tumor growth suppresses fibrosis in TAC-operated female mice. (A). Representative paraffin-embedded heart sections of TAC-operated, PyMT-bearing and non-cancer-bearing female mice stained with Masson’s trichrome to visualize fibrosis. Scale bar: 500 µm (top) and 50 µm (bottom). (B). Quantification of the level of fibrosis (%) by Masson’s trichrome staining in TAC-operated, PyMT-bearing (n = 4) and non-cancer-bearing female mice (n = 4), at least 5 random fields were chosen per mouse. (C). Fibrosis hallmark gene markers CTGF and Col1a1 in TAC-operated, PyMT-bearing (n = 8) and non-cancer-bearing (n = 8) female mice, measured using qRT-PCR, normalized to the GAPDH housekeeping gene. (D). Hydroxyproline levels in the heart lysates of TAC-operated, PyMT-bearing (n = 4) and non-cancer-bearing (n = 4) female mice. The results are presented as mean ± SEM, Student’s t-test. * p < 0.05, ** p < 0.01, *** p < 0.001. In (B–D), each dot represents one mouse.

• 

  Figure 3. The protective effect on cardiac remodeling is observed also in metastatic cancer model. (A). Schematic diagram of the experimental timeline. (B). The lungs weight/body weight ratio (LW/BW mg/gr) of TAC-operated, PyMT-injected and non-injected mice. (C). Representative images of the H&E staining of lungs of TAC-operated, PyMT-injected and non-injected mice. Yellow arrows indicate some of the metastatic lesions. Scale bar 1000 µm. (D). The fractional shortening (FS) of TAC-operated PyMT-injected and non-injected mice at endpoint. Calculated based on parameters in Supplementary Table S3. (E). The ventricular weight/body weight ratio (VW/BW mg/gr) of TAC-operated, PyMT-injected and non-cancer-bearing mice. The results are presented as mean ± SEM, Student’s t-test * p < 0.05. (n = 3 in each group).

• 

  Figure 4. Tumor growth induces cardiac macrophage polarization. (A–I) The levels of macrophage M1 and M2 hallmark gene markers F4/80 (A), iNOS (B), CD206 (C), ARG1 (D), CD163 (E), INFγ (F), TNFα (G), IL-13 (H) and CCL2 (I) in the hearts of TAC-operated, PyMT-bearing (n = 8) and non-cancer-bearing (n = 8) mice, measured using qRT-PCR, normalized to the GAPDH housekeeping gene. The results are presented as mean ± SEM, Student’s t-test. * p < 0.05, ** p < 0.01. Each dot represents one mouse.

• 

  Figure 5. Cardiac beneficial phenotype in PyMT-bearing mice is abrogated in macrophage-depleted mice. (A). Schematic diagram of the experimental timeline. Clodronate or PBS (control) liposomes were intraperitoneal (IP) injected at day 0 together with PyMT cancer cell implantation or not (control), and on day 5, a TAC was performed. Subsequently, clodronate/PBS liposomes were injected twice a week until sacrifice. (B). The tumor weight of clodronate- and control liposome-injected groups at the endpoint. (C,D). The fractional shortening (FS), (C), calculated from echocardiography data, calculated based on parameters in Supplementary Table S4 and ventricular weight/body weight ratio (VW/BW), (D) in the four mouse cohorts. (E,H). The heart expression levels of hypertrophy markers ANP (E) and BNP (F) and fibrosis markers TGFβ3 (G) and CTGF (H), measured using qRT-PCR and normalized to the HSP90 housekeeping gene. The results are presented as mean ± SEM, Student’s t-test. * p < 0.05, ** p < 0.01, non specific (ns). In (B–H), each dot represents one mouse. (n = 5 in all groups).

• 

  Figure 6. Graphical abstract describing the manuscript’s main findings. Cancer growth suppresses fibrosis, inhibits cardiac hypertrophy and ameliorates cardiac contractile function. This is achieved via an M1-to-M2 macrophage polarization in the heart, while M2-to-M1 macrophage polarization occurs in the tumor.