AKT1[low] quiescent cancer cells persist after neoadjuvant chemotherapy in triple negative breast cancer

Background: Absence of pathologic complete response (pCR) to neoadjuvant chemotherapy (NACT) correlates with poor long-term survival in patients with triple negative breast cancer (TNBC). These incomplete treatment responses are likely determined by mechanisms that enable cancer cells to resist being killed. However, the detailed characterization of a drug-resistant cancer cell state in residual TNBC tissue after NACT has remained elusive. AKT1(low) quiescent cancer cells (QCCs) are a quiescent, epigenetically plastic, and chemotherapy-resistant subpopulation initially identified in experimental cancer models. Here, we asked whether QCCs exist in primary tumors from patients with TNBC and persist after treatment with NACT. Methods: We obtained pre-treatment biopsy, post-treatment mastectomy, and metastatic specimens from a retrospective cohort of TNBC patients treated with NACT at Massachusetts General Hospital (n = 25). Using quantitative automated immunofluorescence microscopy, QCCs were identified as AKT(low)/H3K9me2(low)/HES1(high) cancer cells using prespecified immunofluorescence intensity thresholds. QCCs were represented in 2D and 3D digital tumor maps and QCC percentage (QCC-P) and QCC cluster index (QCC-CI) were determined for each sample. Results: We showed that QCCs exist as non-random and heterogeneously distributed clusters within primary breast tumors. In addition, these QCC clusters persist after treatment with multi-agent, multi-cycle, neoadjuvant chemotherapy in both residual primary tumors and nodal and distant metastases in patients with triple negative breast cancer. Conclusions: These first-in-human data potentially qualify AKT1(low) quiescent cancer cells as a non-genetic cell state that persists after neoadjuvant chemotherapy in triple negative breast cancer patients and warrants further study

AKT1[low] quiescent cancer cells persist after neoadjuvant chemotherapy in triple negative breast cancer

Background: Absence of pathologic complete response (pCR) to neoadjuvant chemotherapy (NACT) correlates with poor long-term survival in patients with triple negative breast cancer (TNBC). These incomplete treatment responses are likely determined by mechanisms that enable cancer cells to resist being killed. However, the detailed characterization of a drug-resistant cancer cell state in residual TNBC tissue after NACT has remained elusive. AKT1(low) quiescent cancer cells (QCCs) are a quiescent, epigenetically plastic, and chemotherapy-resistant subpopulation initially identified in experimental cancer models. Here, we asked whether QCCs exist in primary tumors from patients with TNBC and persist after treatment with NACT. Methods: We obtained pre-treatment biopsy, post-treatment mastectomy, and metastatic specimens from a retrospective cohort of TNBC patients treated with NACT at Massachusetts General Hospital (n = 25). Using quantitative automated immunofluorescence microscopy, QCCs were identified as AKT(low)/H3K9me2(low)/HES1(high) cancer cells using prespecified immunofluorescence intensity thresholds. QCCs were represented in 2D and 3D digital tumor maps and QCC percentage (QCC-P) and QCC cluster index (QCC-CI) were determined for each sample. Results: We showed that QCCs exist as non-random and heterogeneously distributed clusters within primary breast tumors. In addition, these QCC clusters persist after treatment with multi-agent, multi-cycle, neoadjuvant chemotherapy in both residual primary tumors and nodal and distant metastases in patients with triple negative breast cancer. Conclusions: These first-in-human data potentially qualify AKT1(low) quiescent cancer cells as a non-genetic cell state that persists after neoadjuvant chemotherapy in triple negative breast cancer patients and warrants further study

Stromal and epithelial transcriptional map of initiation progression and metastatic potential of human prostate cancer

While progression from normal prostatic epithelium to invasive cancer is driven by molecular alterations, tumor cells and cells in the cancer microenvironment are co-dependent and co-evolve. Few human studies to date have focused on stroma. Here, we performed gene expression profiling of laser capture microdissected normal non-neoplastic prostate epithelial tissue and compared it to non-transformed and neoplastic low-grade and high-grade prostate epithelial tissue from radical prostatectomies, each with its immediately surrounding stroma. Whereas benign epithelium in prostates with and without tumor were similar in gene expression space, stroma away from tumor was significantly different from that in prostates without cancer. A stromal gene signature reflecting bone remodeling and immune-related pathways was upregulated in high compared to low-Gleason grade cases. In validation data, the signature discriminated cases that developed metastasis from those that did not. These data suggest that the microenvironment may influence prostate cancer initiation, maintenance, and metastatic progression

Additional file 1: of AKT1low quiescent cancer cells persist after neoadjuvant chemotherapy in triple negative breast cancer

S2 Antibody target specificity is unaffected by sequence of primary antibody application. Merged (right) and single color (left) confocal microscopy images at × 60 of an untreated primary TNBC tumor stained in an alternate sequence: pan-AKT ➔ H3K9me2 ➔ HES1 (c.f. standard sequence of H3K9me2 ➔ pan-AKT ➔ HES1) demonstrating consistent cytoplasmic pan-AKT (green) and HES1 (red) staining and nuclear H3K9me2 (yellow) staining in an example QCC (white arrows). (PDF 3624 kb

Additional file 2: of AKT1low quiescent cancer cells persist after neoadjuvant chemotherapy in triple negative breast cancer

S1 Determination of fluorescence intensity thresholds and staining reproducibility. For each marker (HES1, H3K9me2, pan-AKT) the proportion of cells at a specific fluorescence intensity level was different between sequential sections from control tumor 4, stained simultaneously (S1A and S1B, respectively). QCC percentage (red bars) and QCC density (box and whisker plots) in control tumors 1–4 increased proportionally at 25%, 33%, and 50% thresholds (S1C, S1D, and S1E, respectively). (PDF 2666 kb

Embryonic transcription factor SOX9 drives breast cancer endocrine resistance.

The estrogen receptor (ER) drives the growth of most luminal breast cancers and is the primary target of endocrine therapy. Although ER blockade with drugs such as tamoxifen is very effective, a major clinical limitation is the development of endocrine resistance especially in the setting of metastatic disease. Preclinical and clinical observations suggest that even following the development of endocrine resistance, ER signaling continues to exert a pivotal role in tumor progression in the majority of cases. Through the analysis of the ER cistrome in tamoxifen-resistant breast cancer cells, we have uncovered a role for an RUNX2-ER complex that stimulates the transcription of a set of genes, including most notably the stem cell factor SOX9, that promote proliferation and a metastatic phenotype. We show that up-regulation of SOX9 is sufficient to cause relative endocrine resistance. The gain of SOX9 as an ER-regulated gene associated with tamoxifen resistance was validated in a unique set of clinical samples supporting the need for the development of improved ER antagonists

Embryonic transcription factor SOX9 drives breast cancer endocrine resistance

The estrogen receptor (ER) drives the growth of most luminal breast cancers and is the primary target of endocrine therapy. Although ER blockade with drugs such as tamoxifen is very effective, a major clinical limitation is the development of endocrine resistance especially in the setting of metastatic disease. Preclinical and clinical observations suggest that even following the development of endocrine resistance, ER signaling continues to exert a pivotal role in tumor progression in the majority of cases. Through the analysis of the ER cistrome in tamoxifen-resistant breast cancer cells, we have uncovered a role for an RUNX2-ER complex that stimulates the transcription of a set of genes, including most notably the stem cell factor SOX9, that promote proliferation and a metastatic phenotype. We show that up-regulation of SOX9 is sufficient to cause relative endocrine resistance. The gain of SOX9 as an ER-regulated gene associated with tamoxifen resistance was validated in a unique set of clinical samples supporting the need for the development of improved ER antagonists

Inhibition of de novo lipogenesis targets androgen receptor signaling in castration-resistant prostate cancer

A hallmark of prostate cancer progression is dysregulation of lipid metabolism via overexpression of fatty acid synthase (FASN), a key enzyme in de novo fatty acid synthesis. Metastatic castration-resistant prostate cancer (mCRPC) develops resistance to inhibitors of androgen receptor (AR) signaling through a variety of mechanisms, including the emergence of the constitutively active AR variant V7 (AR-V7). Here, we developed an FASN inhibitor (IPI-9119) and demonstrated that selective FASN inhibition antagonizes CRPC growth through metabolic reprogramming and results in reduced protein expression and transcriptional activity of both full-length AR (AR-FL) and AR-V7. Activation of the reticulum endoplasmic stress response resulting in reduced protein synthesis was involved in IPI-9119-mediated inhibition of the AR pathway. In vivo, IPI-9119 reduced growth of AR-V7-driven CRPC xenografts and human mCRPC-derived organoids and enhanced the efficacy of enzalutamide in CRPC cells. In human mCRPC, both FASN and AR-FL were detected in 87% of metastases. AR-V7 was found in 39% of bone metastases and consistently coexpressed with FASN. In patients treated with enzalutamide and/or abiraterone FASN/AR-V7 double-positive metastases were found in 77% of cases. These findings provide a compelling rationale for the use of FASN inhibitors in mCRPCs, including those overexpressing AR-V71162631640sem informaçãosem informaçãoThis work was supported by Department of Defense (DoD) IMPACT Grant PC160357 (to M.L., S.M.D., and S.R.P.), DoD synergistic Grant W81XWH1410405 (to M.L. and U.M.), NIH Grants R01-CA131945 and P50 CA90381, and the Prostate Cancer Foundation (PCF) (M.L.). G.Z. is a recipient of the DoD Idea Development Award for New Investigators (PC150263) and a Claudia Adams Barr Award in Innovative Cancer Research from the Dana-Farber Cancer Institute. The rapid autopsy material is the result of work supported by resources by the DoD (Award W81XWH-14-2-0183), the Pacific Northwest Prostate Cancer Specialized Programs of Research Excellence (SPORE) (Grant P50CA97186), and the Institute for Prostate Cancer Research. L. M.B. is supported by a Future Fellowship from the Australian Research Council (Fellowship FT130101004) and grant support from the Movember Foundation/ PCF of Australi