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Role of IL13RA2 in Sunitinib Resistance in Clear Cell Renal Cell Carcinoma.

Shibasaki N, Yamasaki T, Kanno T, Arakaki R, Sakamoto H, Utsunomiya N, Inoue T, Tsuruyama T, Nakamura E, Ogawa O, Kamba T - PLoS ONE (2015)

Bottom Line: Comparing gene expression profiles between the two xenograft models with different sensitivity to sunitinib, we identified interleukin 13 receptor alpha 2 (IL13RA2) as a candidate molecule associated with the acquired sunitinib-resistance in ccRCC.Conversely, shRNA-mediated knockdown of IL13RA2 successfully overcame the sunitinib-resistance in Caki-1 cells.Histopathological analyses revealed that IL13RA2 repressed sunitinib-induced apoptosis without increasing tumor vasculature in vivo.

View Article: PubMed Central - PubMed

Affiliation: Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.

ABSTRACT
Vascular endothelial growth factor (VEGF) and mammalian target of rapamycin are well-known therapeutic targets for renal cell carcinoma (RCC). Sunitinib is an agent that targets VEGF receptors and is considered to be a standard treatment for metastatic or unresectable clear cell RCC (ccRCC). However, ccRCC eventually develops resistance to sunitinib in most cases, and the mechanisms underlying this resistance are not fully elucidated. In the present study, we established unique primary xenograft models, KURC1 (Kyoto University Renal Cancer 1) and KURC2, from freshly isolated ccRCC specimens. The KURC1 xenograft initially responded to sunitinib treatment, however finally acquired resistance. KURC2 retained sensitivity to sunitinib for over 6 months. Comparing gene expression profiles between the two xenograft models with different sensitivity to sunitinib, we identified interleukin 13 receptor alpha 2 (IL13RA2) as a candidate molecule associated with the acquired sunitinib-resistance in ccRCC. And patients with high IL13RA2 expression in immunohistochemistry in primary ccRCC tumor tends to have sunitinib-resistant metastatic site. Next, we showed that sunitinib-sensitive 786-O cells acquired resistance in vivo when IL13RA2 was overexpressed. Conversely, shRNA-mediated knockdown of IL13RA2 successfully overcame the sunitinib-resistance in Caki-1 cells. Histopathological analyses revealed that IL13RA2 repressed sunitinib-induced apoptosis without increasing tumor vasculature in vivo. To our knowledge, this is a novel mechanism of developing resistance to sunitinib in a certain population of ccRCC, and these results indicate that IL13RA2 could be one of potential target to overcome sunitinib resistance.

No MeSH data available.


Related in: MedlinePlus

Evaluation of IL13RA2 mRNA and protein expression.(A) Evaluation of IL13RA2 mRNA expression in KURC1 and KURC2 xenograft tumors treated with sunitinib or vehicle by qPCR. All samples were prepared in triplicate and data are presented as the mean ± SE from indicated number of samples. Columns, mean; bar, SE. The difference in the mRNA expression levels between the sunitinib-treated group and control or sensitive group in KURC1 was statistically significant (*P < 0.01; Students’ t-test). There was no significant difference in KURC2 groups. (B) Immunohistochemical staining of IL13RA2 in KURC1 xenograft tumors. Scale bar, 50 μm. (C) IL13RA2 expression in human ccRCC tumors with the response to sunitinib treatment evaluated by immunohistochemistry. ccRCC tumor samples were collected from patients prior to sunitinib treatment. Left: representative pictures of immunohistochemistry sections of tumors showing none, weak, or strong staining for IL13RA2. Right: ratio of IL13RA2 expression pattern and correlation of the response to sunitinib treatment. Scale bar, 100 μm.
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pone.0130980.g002: Evaluation of IL13RA2 mRNA and protein expression.(A) Evaluation of IL13RA2 mRNA expression in KURC1 and KURC2 xenograft tumors treated with sunitinib or vehicle by qPCR. All samples were prepared in triplicate and data are presented as the mean ± SE from indicated number of samples. Columns, mean; bar, SE. The difference in the mRNA expression levels between the sunitinib-treated group and control or sensitive group in KURC1 was statistically significant (*P < 0.01; Students’ t-test). There was no significant difference in KURC2 groups. (B) Immunohistochemical staining of IL13RA2 in KURC1 xenograft tumors. Scale bar, 50 μm. (C) IL13RA2 expression in human ccRCC tumors with the response to sunitinib treatment evaluated by immunohistochemistry. ccRCC tumor samples were collected from patients prior to sunitinib treatment. Left: representative pictures of immunohistochemistry sections of tumors showing none, weak, or strong staining for IL13RA2. Right: ratio of IL13RA2 expression pattern and correlation of the response to sunitinib treatment. Scale bar, 100 μm.

Mentions: Among the three genes, qPCR analysis confirmed that IL13RA2 mRNA was significantly upregulated in sunitinib-resistant KURC1 compared with sunitinib-sensitive KURC1 or those treated with vehicles (Fig 2A and 2B). The other candidate genes, FAM5B and MTMR7, were also up-regulated in our experimental model of KURC1 and KURC2. But the expression was very low level, therefore we didn’t pick up these genes (S2 Fig).


Role of IL13RA2 in Sunitinib Resistance in Clear Cell Renal Cell Carcinoma.

Shibasaki N, Yamasaki T, Kanno T, Arakaki R, Sakamoto H, Utsunomiya N, Inoue T, Tsuruyama T, Nakamura E, Ogawa O, Kamba T - PLoS ONE (2015)

Evaluation of IL13RA2 mRNA and protein expression.(A) Evaluation of IL13RA2 mRNA expression in KURC1 and KURC2 xenograft tumors treated with sunitinib or vehicle by qPCR. All samples were prepared in triplicate and data are presented as the mean ± SE from indicated number of samples. Columns, mean; bar, SE. The difference in the mRNA expression levels between the sunitinib-treated group and control or sensitive group in KURC1 was statistically significant (*P < 0.01; Students’ t-test). There was no significant difference in KURC2 groups. (B) Immunohistochemical staining of IL13RA2 in KURC1 xenograft tumors. Scale bar, 50 μm. (C) IL13RA2 expression in human ccRCC tumors with the response to sunitinib treatment evaluated by immunohistochemistry. ccRCC tumor samples were collected from patients prior to sunitinib treatment. Left: representative pictures of immunohistochemistry sections of tumors showing none, weak, or strong staining for IL13RA2. Right: ratio of IL13RA2 expression pattern and correlation of the response to sunitinib treatment. Scale bar, 100 μm.
© Copyright Policy
Related In: Results  -  Collection

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pone.0130980.g002: Evaluation of IL13RA2 mRNA and protein expression.(A) Evaluation of IL13RA2 mRNA expression in KURC1 and KURC2 xenograft tumors treated with sunitinib or vehicle by qPCR. All samples were prepared in triplicate and data are presented as the mean ± SE from indicated number of samples. Columns, mean; bar, SE. The difference in the mRNA expression levels between the sunitinib-treated group and control or sensitive group in KURC1 was statistically significant (*P < 0.01; Students’ t-test). There was no significant difference in KURC2 groups. (B) Immunohistochemical staining of IL13RA2 in KURC1 xenograft tumors. Scale bar, 50 μm. (C) IL13RA2 expression in human ccRCC tumors with the response to sunitinib treatment evaluated by immunohistochemistry. ccRCC tumor samples were collected from patients prior to sunitinib treatment. Left: representative pictures of immunohistochemistry sections of tumors showing none, weak, or strong staining for IL13RA2. Right: ratio of IL13RA2 expression pattern and correlation of the response to sunitinib treatment. Scale bar, 100 μm.
Mentions: Among the three genes, qPCR analysis confirmed that IL13RA2 mRNA was significantly upregulated in sunitinib-resistant KURC1 compared with sunitinib-sensitive KURC1 or those treated with vehicles (Fig 2A and 2B). The other candidate genes, FAM5B and MTMR7, were also up-regulated in our experimental model of KURC1 and KURC2. But the expression was very low level, therefore we didn’t pick up these genes (S2 Fig).

Bottom Line: Comparing gene expression profiles between the two xenograft models with different sensitivity to sunitinib, we identified interleukin 13 receptor alpha 2 (IL13RA2) as a candidate molecule associated with the acquired sunitinib-resistance in ccRCC.Conversely, shRNA-mediated knockdown of IL13RA2 successfully overcame the sunitinib-resistance in Caki-1 cells.Histopathological analyses revealed that IL13RA2 repressed sunitinib-induced apoptosis without increasing tumor vasculature in vivo.

View Article: PubMed Central - PubMed

Affiliation: Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.

ABSTRACT
Vascular endothelial growth factor (VEGF) and mammalian target of rapamycin are well-known therapeutic targets for renal cell carcinoma (RCC). Sunitinib is an agent that targets VEGF receptors and is considered to be a standard treatment for metastatic or unresectable clear cell RCC (ccRCC). However, ccRCC eventually develops resistance to sunitinib in most cases, and the mechanisms underlying this resistance are not fully elucidated. In the present study, we established unique primary xenograft models, KURC1 (Kyoto University Renal Cancer 1) and KURC2, from freshly isolated ccRCC specimens. The KURC1 xenograft initially responded to sunitinib treatment, however finally acquired resistance. KURC2 retained sensitivity to sunitinib for over 6 months. Comparing gene expression profiles between the two xenograft models with different sensitivity to sunitinib, we identified interleukin 13 receptor alpha 2 (IL13RA2) as a candidate molecule associated with the acquired sunitinib-resistance in ccRCC. And patients with high IL13RA2 expression in immunohistochemistry in primary ccRCC tumor tends to have sunitinib-resistant metastatic site. Next, we showed that sunitinib-sensitive 786-O cells acquired resistance in vivo when IL13RA2 was overexpressed. Conversely, shRNA-mediated knockdown of IL13RA2 successfully overcame the sunitinib-resistance in Caki-1 cells. Histopathological analyses revealed that IL13RA2 repressed sunitinib-induced apoptosis without increasing tumor vasculature in vivo. To our knowledge, this is a novel mechanism of developing resistance to sunitinib in a certain population of ccRCC, and these results indicate that IL13RA2 could be one of potential target to overcome sunitinib resistance.

No MeSH data available.


Related in: MedlinePlus