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Nrh protein expression in healthy and tumoral tissues (A) Nrh protein expression in human healthy tissues. Immunohistochemistry on tissue array (B) Nrh expression assessed by western blot in cell lysate of liver cancer. (NAT) normal adjacent tissue.

Time-lapse imaging of dTAT-NDP action on CAL-51 breast cancer cell line

Fig. S8. Mechanism for irradiation-free dTAT peptide internalization Fig; S9. dTAT peptide treatment increases apoptosis of tumor cells in vivo

Drug resistance and metastatic relapse remain a top challenge in breast cancer treatment. In this study, we present preclinical evidence for a strategy to eradicate advanced breast cancers by targeting the BCL-2 homolog Nrh/BCL2L10, which we discovered to be overexpressed in >45% of a large cohort of breast invasive carcinomas. Nrh expression in these tumors correlated with reduced metastasis-free survival, and we determined it to be an independent marker of poor prognosis. Nrh protein localized to the endoplasmic reticulum. Mechanistic investigations showed that Nrh made BH4 domain–dependent interactions with the ligand-binding domain of the inositol-1,4,5-triphosphate receptor (IP3R), a type 1/3 Ca2+ channel, allowing Nrh to negatively regulate ER-Ca2+ release and to mediate antiapoptosis. Notably, disrupting Nrh/IP3R complexes by BH4 mimetic peptides was sufficient to inhibit the growth of breast cancer cells in vitro and in vivo. Taken together, our results highlighted Nrh as a novel prognostic marker and a candidate therapeutic target for late stage breast cancers that may be addicted to Nrh.Significance: These findings offer a comprehensive molecular model for the activity of Nrh/BCL2L10, a little studied antiapoptotic molecule, prognostic marker, and candidate drug target in breast cancer. Cancer Res; 78(6); 1404–17. ©2018 AACR.

I- Reagents and antibodies. Vectors. RNA preparation & RT-qPCR -II- Supplementary Table 1: Invasive breast carcinomas patient cohort characteristics -III- Supplementary Table 2: Correlation between Nrh protein expression and the clinicopathologic factors of breast cancer -IV- Supplementary Table 3: Multivariate analysis of clinical parameters predicting shorter DMFS -V- Legend of supplementary movie : Time-lapse imaging of dTAT-NDP action on CAL-51 breast cancer cell line

PDF file - 1195K, Supplementary Figure 4: RPTOR and mTOR silencing impair S6K phosphorylation.

PDF file - 848K, Supplementary Figure 2: Inhibition of mTORC1 activates EMT and reduces cell proliferation.

PDF file - 441K, Supplementary Figure 1: SiRNA screening procedure.

PDF file - 741K, Supplementary Figure 5: Silencing of mTOR and RPTOR activates ZEB1 mRNA expression in various cell lines.

XLSX file - 170K, Supplementary Table 1: Results of the first siRNA screen aimed at identifying new EMT regulators among protein kinases Supplementary Table 2: Selected pro-MET genes from the first siRNA screen Supplementary Table 3: Selected pro-EMT genes from the first siRNA screen Supplementary Table 4: Selected pro-MET genes challenged with 2 additional siRNAs Supplementary Table 5: Selected pro-EMT genes challenged with 2 additional siRNAs

PDF file - 91K

Epithelial-to-mesenchymal transition (EMT) is a transdifferentiation process that converts epithelial cells into highly motile mesenchymal cells. This physiologic process occurs largely during embryonic development but is aberrantly reactivated in different pathologic situations, including fibrosis and cancer. We conducted a siRNA screening targeted to the human kinome with the aim of discovering new EMT effectors. With this approach, we have identified mTOR complex 1 (mTORC1), a nutrient sensor that controls protein and lipid synthesis, as a key regulator of epithelial integrity. Using a combination of RNAi and pharmacologic approaches, we report here that inhibition of either mTOR or RPTOR triggers EMT in mammary epithelial cells. This EMT was characterized by the induction of the mesenchymal markers such as fibronectin, vimentin, and PAI-1, together with the repression of epithelial markers such as E-cadherin and ZO-3. In addition, mTORC1 blockade enhanced in vivo migratory properties of mammary cells and induced EMT independent of the TGF-β pathway. Finally, among the transcription factors known to activate EMT, both ZEB1 and ZEB2 were upregulated following mTOR repression. Their increased expression correlated with a marked reduction in miR-200b and miR-200c mRNA levels, two microRNAs known to downregulate ZEB1 and ZEB2 expression. Taken together, our findings unravel a novel function for mTORC1 in maintaining the epithelial phenotype and further indicate that this effect is mediated through the opposite regulation of ZEB1/ZEB2 and miR-200b and miR-200c. Furthermore, these results suggest a plausible etiologic explanation for the progressive pulmonary fibrosis, a frequent adverse condition associated with the therapeutic use of mTOR inhibitors. Cancer Res; 73(22); 6621–31. ©2013 AACR.

Overexpression of Bcl-2 proteins such as Bcl2L10, also referred to as Nrh, is associated with resistance to therapy and poor survival in various cancers, including breast cancer, lung cancer and leukemia. The single nucleotide polymorphism (SNP) of BCL2L10 in its BH4 domain at position 11 (BCL2L10 Leu11Arg, rs2231292), corresponding to position 11 in the Nrh open reading frame, is reported to lower resistance towards chemotherapy, with patients showing better survival in the context of acute leukemia and colorectal cancer. Using cellular models and clinical data, we aimed to extend this knowledge to breast cancer. We report that the homozygous status of the Nrh Leu11Arg isoform (Nrh-R) is found in 9.7–11% percent of the clinical datasets studied. Furthermore, Nrh-R confers higher sensitivity towards Thapsigargin-induced cell death compared to the NrhL isoform, due to altered interactions with IP3R1 Ca2+ channels in the former case. Collectively, our data show that cells expressing the NrhR isoform are more prone to death triggered by Ca2+ stress inducers, compared to Nrh-L expressing cells. Analysis of breast cancer cohorts revealed that patients genotyped as Nrh-R/Nrh-R may have a better outcome. Overall, this study supports the notion that the rs2231292 Nrh SNP could be used as a predictive tool regarding chemoresistance, improving therapeutic decision-making processes. Moreover, it sheds new light on the contribution of the BH4 domain to the anti-apoptotic function of Nrh and identifies the IP3R1/Nrh complex as a potential therapeutic target in the context of breast cancer.