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Adipose cells promote resistance of breast cancer cells to trastuzumab-mediated antibody-dependent cellular cytotoxicity.

Duong MN, Cleret A, Matera EL, Chettab K, Mathé D, Valsesia-Wittmann S, Clémenceau B, Dumontet C - Breast Cancer Res. (2015)

Bottom Line: The results were validated in vivo in a mouse xenograft model.Using a transcriptomic approach, we found that cancer cells undergo major modifications when exposed to adipocyte-conditioned medium.Collectively, our findings underline the importance of adipose tissue in the resistance to trastuzumab and suggest that approaches targeting the adipocyte-cancer cell crosstalk may help sensitize cancer cells to trastuzumab-based therapy.

View Article: PubMed Central - PubMed

Affiliation: Centre de Recherche en Cancérologie de Lyon (CRCL), INSERM UMR 1052, CNRS 5286, 8 Avenue Rockefeller, 69008, Lyon, France. mn.duong@hotmail.com.

ABSTRACT

Introduction: Trastuzumab has been used in the treatment of human epidermal growth factor receptor 2 (HER2)-expressing breast cancer, but its efficacy is limited by de novo or acquired resistance. Although many mechanisms have been proposed to explain resistance to trastuzumab, little is known concerning the role of the tumor microenvironment. Given the importance of antibody-dependent cellular cytotoxicity (ADCC) in the antitumor effect of trastuzumab and the abundance of adipose tissue in the breast, we investigated the impact of adipocytes on ADCC.

Methods: We set up a coculture system to study the effect of adipocytes on ADCC in vitro. The results were validated in vivo in a mouse xenograft model.

Results: We found that adipocytes, as well as preadipocytes, inhibited trastuzumab-mediated ADCC in HER2-expressing breast cancer cells via the secretion of soluble factors. The inhibition of ADCC was not due to titration or degradation of the antibody. We found that adipose cells decreased the secretion of interferon-γ by natural killer cells, but did not alter natural killer cells' cytotoxicity. Preincubation of breast cancer cells with the conditioned medium derived from adipocytes reduced the sensitivity of cancer cells to ADCC. Using a transcriptomic approach, we found that cancer cells undergo major modifications when exposed to adipocyte-conditioned medium. Importantly, breast tumors grafted next to lipomas displayed resistance to trastuzumab in mouse xenograft models.

Conclusions: Collectively, our findings underline the importance of adipose tissue in the resistance to trastuzumab and suggest that approaches targeting the adipocyte-cancer cell crosstalk may help sensitize cancer cells to trastuzumab-based therapy.

No MeSH data available.


Related in: MedlinePlus

#hMADS adipocytes and hMADS preadipocytes inhibit antibody-dependent cellular cytotoxicity. (A) Schema of antibody-dependent cellular cytotoxicity (ADCC) assays in the absence (left) or the presence (right) of adipose cells. (B) ADCC assays on BT-474 and MDA-MB-453 cells as described in (A). (C) ADCC assay on BT-474 cells performed in hypoxic conditions with 1% O2. The cytotoxicity was normalized to the control differentiated medium as 100%. Mean ± SD values of three independent experiments, each performed in triplicate, are shown (B and C). hMADS, Human multipotent adipose-derived stem cells; #hMADS, Differentiated human multipotent adipose-derived stem cells; HME, Human mammary epithelial cell. *P < 0.05; **P < 0.01; ns, Not significant.
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Fig1: #hMADS adipocytes and hMADS preadipocytes inhibit antibody-dependent cellular cytotoxicity. (A) Schema of antibody-dependent cellular cytotoxicity (ADCC) assays in the absence (left) or the presence (right) of adipose cells. (B) ADCC assays on BT-474 and MDA-MB-453 cells as described in (A). (C) ADCC assay on BT-474 cells performed in hypoxic conditions with 1% O2. The cytotoxicity was normalized to the control differentiated medium as 100%. Mean ± SD values of three independent experiments, each performed in triplicate, are shown (B and C). hMADS, Human multipotent adipose-derived stem cells; #hMADS, Differentiated human multipotent adipose-derived stem cells; HME, Human mammary epithelial cell. *P < 0.05; **P < 0.01; ns, Not significant.

Mentions: To investigate the role of preadipocytes and adipocytes, we performed ADCC assays on HER2-positive (HER2+) estrogen receptor (ER)-positive human breast cancer cells (BT-474) and NK cells (NK-92-CD16) in the presence of undifferentiated hMADS or #hMADS cells (corresponding to models of preadipocytes and adipocytes, respectively) or their control media (Figure 1A). NK-92-CD16 cells alone did not exhibit any cytotoxicity on BT-474 cells in the absence of trastuzumab during the 4-hour assays (Additional file 3: Figure S1A). As shown in Figure 1B and Additional file 3: Figure S1A, both hMADS and #hMADS reduced trastuzumab-mediated ADCC by approximately 30% as compared with the control media. In contrast, no inhibition of ADCC was observed in the presence of immortalized human mammary epithelial hTERT-HME1 cells (Figure 1B), indicating that the inhibition was not due to the physical presence of a feeder cell layer, but was specific to adipose cells. Similar results on the adipose-mediated inhibition of ADCC were obtained with the HER2+/ER− MDA-MB-453 cells (Figure 1B), suggesting that the inhibitory effect of adipose cells on ADCC was independent of the ER status on cancer cells. We also found that adipose cells inhibited ADCC to a lesser extent with HER2+/ER− SK-BR-3 cells, but not with HER2+/ER+ MDA-MB-361 cells (Additional file 3: Figure S1B). This was not related to the difference in levels of HER2 expression between these cell lines (Additional file 4: Figure S2). Therefore, we chose BT-474 cells as target cells for later experiments. Collectively, these results indicate that adipose cells (both hMADS and #hMADS) inhibited trastuzumab-mediated ADCC.Figure 1


Adipose cells promote resistance of breast cancer cells to trastuzumab-mediated antibody-dependent cellular cytotoxicity.

Duong MN, Cleret A, Matera EL, Chettab K, Mathé D, Valsesia-Wittmann S, Clémenceau B, Dumontet C - Breast Cancer Res. (2015)

#hMADS adipocytes and hMADS preadipocytes inhibit antibody-dependent cellular cytotoxicity. (A) Schema of antibody-dependent cellular cytotoxicity (ADCC) assays in the absence (left) or the presence (right) of adipose cells. (B) ADCC assays on BT-474 and MDA-MB-453 cells as described in (A). (C) ADCC assay on BT-474 cells performed in hypoxic conditions with 1% O2. The cytotoxicity was normalized to the control differentiated medium as 100%. Mean ± SD values of three independent experiments, each performed in triplicate, are shown (B and C). hMADS, Human multipotent adipose-derived stem cells; #hMADS, Differentiated human multipotent adipose-derived stem cells; HME, Human mammary epithelial cell. *P < 0.05; **P < 0.01; ns, Not significant.
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Related In: Results  -  Collection

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Fig1: #hMADS adipocytes and hMADS preadipocytes inhibit antibody-dependent cellular cytotoxicity. (A) Schema of antibody-dependent cellular cytotoxicity (ADCC) assays in the absence (left) or the presence (right) of adipose cells. (B) ADCC assays on BT-474 and MDA-MB-453 cells as described in (A). (C) ADCC assay on BT-474 cells performed in hypoxic conditions with 1% O2. The cytotoxicity was normalized to the control differentiated medium as 100%. Mean ± SD values of three independent experiments, each performed in triplicate, are shown (B and C). hMADS, Human multipotent adipose-derived stem cells; #hMADS, Differentiated human multipotent adipose-derived stem cells; HME, Human mammary epithelial cell. *P < 0.05; **P < 0.01; ns, Not significant.
Mentions: To investigate the role of preadipocytes and adipocytes, we performed ADCC assays on HER2-positive (HER2+) estrogen receptor (ER)-positive human breast cancer cells (BT-474) and NK cells (NK-92-CD16) in the presence of undifferentiated hMADS or #hMADS cells (corresponding to models of preadipocytes and adipocytes, respectively) or their control media (Figure 1A). NK-92-CD16 cells alone did not exhibit any cytotoxicity on BT-474 cells in the absence of trastuzumab during the 4-hour assays (Additional file 3: Figure S1A). As shown in Figure 1B and Additional file 3: Figure S1A, both hMADS and #hMADS reduced trastuzumab-mediated ADCC by approximately 30% as compared with the control media. In contrast, no inhibition of ADCC was observed in the presence of immortalized human mammary epithelial hTERT-HME1 cells (Figure 1B), indicating that the inhibition was not due to the physical presence of a feeder cell layer, but was specific to adipose cells. Similar results on the adipose-mediated inhibition of ADCC were obtained with the HER2+/ER− MDA-MB-453 cells (Figure 1B), suggesting that the inhibitory effect of adipose cells on ADCC was independent of the ER status on cancer cells. We also found that adipose cells inhibited ADCC to a lesser extent with HER2+/ER− SK-BR-3 cells, but not with HER2+/ER+ MDA-MB-361 cells (Additional file 3: Figure S1B). This was not related to the difference in levels of HER2 expression between these cell lines (Additional file 4: Figure S2). Therefore, we chose BT-474 cells as target cells for later experiments. Collectively, these results indicate that adipose cells (both hMADS and #hMADS) inhibited trastuzumab-mediated ADCC.Figure 1

Bottom Line: The results were validated in vivo in a mouse xenograft model.Using a transcriptomic approach, we found that cancer cells undergo major modifications when exposed to adipocyte-conditioned medium.Collectively, our findings underline the importance of adipose tissue in the resistance to trastuzumab and suggest that approaches targeting the adipocyte-cancer cell crosstalk may help sensitize cancer cells to trastuzumab-based therapy.

View Article: PubMed Central - PubMed

Affiliation: Centre de Recherche en Cancérologie de Lyon (CRCL), INSERM UMR 1052, CNRS 5286, 8 Avenue Rockefeller, 69008, Lyon, France. mn.duong@hotmail.com.

ABSTRACT

Introduction: Trastuzumab has been used in the treatment of human epidermal growth factor receptor 2 (HER2)-expressing breast cancer, but its efficacy is limited by de novo or acquired resistance. Although many mechanisms have been proposed to explain resistance to trastuzumab, little is known concerning the role of the tumor microenvironment. Given the importance of antibody-dependent cellular cytotoxicity (ADCC) in the antitumor effect of trastuzumab and the abundance of adipose tissue in the breast, we investigated the impact of adipocytes on ADCC.

Methods: We set up a coculture system to study the effect of adipocytes on ADCC in vitro. The results were validated in vivo in a mouse xenograft model.

Results: We found that adipocytes, as well as preadipocytes, inhibited trastuzumab-mediated ADCC in HER2-expressing breast cancer cells via the secretion of soluble factors. The inhibition of ADCC was not due to titration or degradation of the antibody. We found that adipose cells decreased the secretion of interferon-γ by natural killer cells, but did not alter natural killer cells' cytotoxicity. Preincubation of breast cancer cells with the conditioned medium derived from adipocytes reduced the sensitivity of cancer cells to ADCC. Using a transcriptomic approach, we found that cancer cells undergo major modifications when exposed to adipocyte-conditioned medium. Importantly, breast tumors grafted next to lipomas displayed resistance to trastuzumab in mouse xenograft models.

Conclusions: Collectively, our findings underline the importance of adipose tissue in the resistance to trastuzumab and suggest that approaches targeting the adipocyte-cancer cell crosstalk may help sensitize cancer cells to trastuzumab-based therapy.

No MeSH data available.


Related in: MedlinePlus