RESUMO
Targeting the PI3K-AKT-mTOR pathway is a promising therapeutic strategy for breast cancer treatment. However, low response rates and development of resistance to PI3K-AKT-mTOR inhibitors remain major clinical challenges. Here, we show that MYC activation drives resistance to mTOR inhibitors (mTORi) in breast cancer. Multiomic profiling of mouse invasive lobular carcinoma (ILC) tumors revealed recurrent Myc amplifications in tumors that acquired resistance to the mTORi AZD8055. MYC activation was associated with biological processes linked to mTORi response and counteracted mTORi-induced translation inhibition by promoting translation of ribosomal proteins. In vitro and in vivo induction of MYC conferred mTORi resistance in mouse and human breast cancer models. Conversely, AZD8055-resistant ILC cells depended on MYC, as demonstrated by the synergistic effects of mTORi and MYCi combination treatment. Notably, MYC status was significantly associated with poor response to everolimus therapy in metastatic breast cancer patients. Thus, MYC is a clinically relevant driver of mTORi resistance that may stratify breast cancer patients for mTOR-targeted therapies.
Assuntos
Neoplasias da Mama , Humanos , Animais , Camundongos , Feminino , Neoplasias da Mama/tratamento farmacológico , Inibidores de MTOR , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt , Serina-Treonina Quinases TORRESUMO
PURPOSE: Everolimus plus exemestane (EVE/EXE) is a registered treatment option for ER-positive, HER2-negative (ER +/HER2-) metastatic breast cancer (MBC), but resistance mechanisms limit efficacy. We aimed to find markers that might help select patients with a higher chance on benefit from EVE/EXE. METHODS: Immunohistochemistry (IHC) of PTEN, p-AKT(Thr308), p-AKT(Ser473), p-4EBP1, p-p70S6K, p-S6RP(Ser240/244), p-ERK1/2 and p-S6RP (Ser235/236) was performed on primary tumour tissue and on biopsies immediately taken from ER +/HER2- MBC patients before the start of standard EVE/EXE (Eudract 2013-004120-11). Unsupervised hierarchical clustering was executed to create heatmaps to distinguish subgroups of preferentially activated and less-activated PI3K/MAPK proteins. Uni- and multivariate Cox models were used for associations with PFS. RESULTS: Primary tumour tissue from 145 patients was retrieved. Median PFS was 5.4 months. Patients without (neo)adjuvant therapy (p = 0.03) or bone only disease (p = 0.04) had longer PFS on EVE/EXE. In primary tumours, neither single proteins nor PI3K/MAPK-associated heatmap subgroups were significantly associated with PFS. In 21 patients a non-osseous biopsy obtained before dosing was useful for continuous scoring, which demonstrated upregulation of several proteins as compared to readings in corresponding primary tumour tissues. These comparisons revealed that increased expression of p-4EBP1 was significantly associated with worse PFS (multivariate HR 3.69, p = 0.05). CONCLUSIONS: IHC of single proteins or heatmap subgroups of the differentially activated PI3K/MAPK pathways was not able to discriminate patients on EVE/EXE with poor or better PFS. Upregulation of p-4EBP1 in pre-treatment biopsies as compared to levels in primary tumours pointed towards shorter PFS.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/fisiologia , Fosfatidilinositol 3-Quinases/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Androstadienos/uso terapêutico , Biomarcadores Tumorais/análise , Neoplasias da Mama/metabolismo , Everolimo/uso terapêutico , Feminino , Humanos , Pessoa de Meia-Idade , Intervalo Livre de Progressão , Transdução de Sinais/fisiologiaRESUMO
The phosphatidylinositol-3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways are frequently activated in breast cancer. We recently demonstrated the importance of analyzing multiple proteins as read-out for pathway activation in ER+/HER2- breast cancer, since single proteins are known to provide insufficient information. Here, we determined pathway activation in other primary breast cancer intrinsic subtypes derived from postmenopausal patients. Tumor blocks were recollected, and immunohistochemistry was performed using antibodies against PTEN, p-AKT(Thr308), p-AKT(Ser473), p-p70S6K, p-4EBP1, p-S6RP(Ser235/236) and p-ERK1/2, followed by unsupervised hierarchical clustering. In 32 ER+/HER2+, 37 ER-/HER2+ and 74 triple-negative breast cancer patients, subgroups were identified with preferentially activated (A) and preferentially not activated (N) proteins. These subgroups likely reflect tumors with differences in biological behavior as well as treatment outcome.
Assuntos
Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Transdução de Sinais/fisiologia , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologia , Idoso , Biomarcadores Tumorais/metabolismo , Feminino , Humanos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor ErbB-2/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismoRESUMO
We determined whether progression-free survival (PFS) in metastatic breast cancer (MBC) patients receiving everolimus plus exemestane (EVE/EXE) varies depending on circulating tumour DNA (ctDNA) characteristics. Baseline plasma cell-free DNA (cfDNA) from 164 postmenopausal women with ER-positive, HER2-negative MBC refractory to a nonsteroidal aromatase inhibitor and treated with standard EVE/EXE (Everolimus Biomarker Study, Eudract 2013-004120-11) was characterised for 10 relevant breast cancer genes by next-generation sequencing with molecular barcoding. ctDNA molecule numbers, number of mutations and specific variants were related with PFS and overall survival (OS). Missense hotspot mutations in cfDNA were detected in 125 patients. The median of 54 ctDNA molecules per mL plasma distinguished patients with high and low/no ctDNA load. Patients with low/no ctDNA load (N = 102) showed longer median PFS of 5.7 months (P = 0.006) and OS of 124.8 months (P = 0.008) than patients with high ctDNA load (N = 62; 4.4 months and 107.7 months, respectively) in multivariate analyses. Patients with < 3 specific mutations (N = 135) had longer median PFS of 5.4 months compared to those with ≥ 3 mutations (3.4 months; P < 0.001). In conclusion, MBC patients with low/no ctDNA load or < 3 hotspot mutations experience longer PFS while treated with EVE/EXE.
Assuntos
Androstadienos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , DNA Tumoral Circulante/genética , Everolimo/uso terapêutico , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/sangue , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , DNA Tumoral Circulante/sangue , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Metástase Neoplásica , Pós-Menopausa , Intervalo Livre de Progressão , Estudos RetrospectivosRESUMO
Preclinical studies indicate that activated IGF-1R can drive endocrine resistance in ER-positive (ER+) breast cancer, but its clinical relevance is unknown. We studied the effect of IGF-1R signaling on tamoxifen benefit in patients and we searched for approaches to overcome IGF-1R-mediated tamoxifen failure in cell lines. Primary tumor blocks from postmenopausal ER+ breast cancer patients randomized between adjuvant tamoxifen versus nil were recollected. Immunohistochemistry for IGF-1R, p-IGF-1R/InsR, p-ERα(Ser118), p-ERα(Ser167) and PI3K/MAPK pathway proteins was performed. Multivariate Cox models were employed to assess tamoxifen efficacy. The association between p-IGF-1R/InsR and PI3K/MAPK pathway activation in MCF-7 and T47D cells was analyzed with Western blots. Cell proliferation experiments were performed under various growth-stimulating and -inhibiting conditions. Patients with ER+, IGF-1R-positive breast cancer without p-IGF-1R/InsR staining (n = 242) had tamoxifen benefit (HR 0.41, p = 0.0038), while the results for p-IGF-1R/InsR-positive patients (n = 125) were not significant (HR 0.95, p = 0.3). High p-ERα(Ser118) or p-ERα(Ser167) expression was associated with less tamoxifen benefit. In MCF-7 cells, IGF-1R stimulation increased phosphorylation of PI3K/MAPK proteins and ERα(Ser167) regardless of IGF-1R overexpression. This could be abrogated by the dual IGF-1R/InsR inhibitor linsitinib, but not by the IGF-IR-selective antibody 1H7. In MCF-7 and T47D cells, stimulation of the IGF-1R/InsR pathway resulted in cell proliferation regardless of tamoxifen. Abrogation of cell growth was regained by addition of linsitinib. In conclusion, p-IGF-1R/InsR positivity in ER+ breast cancer is associated with reduced benefit from adjuvant tamoxifen in postmenopausal patients. In cell lines, stimulation rather than overexpression of IGF-1R is driving tamoxifen resistance to be abrogated by linsitinib.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Imidazóis/farmacologia , Pirazinas/farmacologia , Receptor IGF Tipo 1/metabolismo , Receptores de Estrogênio/metabolismo , Tamoxifeno/farmacologia , Idoso , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Sinergismo Farmacológico , Feminino , Humanos , Imidazóis/administração & dosagem , Imuno-Histoquímica , Sistema de Sinalização das MAP Quinases , Células MCF-7 , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Pirazinas/administração & dosagem , Receptor IGF Tipo 1/antagonistas & inibidores , Tamoxifeno/administração & dosagemRESUMO
INTRODUCTION: The presence of tumor-infiltrating lymphocytes (TILs) is correlated with good prognosis and outcome after (immuno)therapy in triple-negative and HER2-positive breast cancer. However, the role of TILs in luminal breast cancer is less clear. Emerging evidence has now demonstrated that genetic aberrations in malignant cells influence the immune landscape of tumors. Phosphatidylinositol 3-kinase (PI3K) is the most common altered pathway in ER-positive breast cancer. It is unknown whether changes in the PI3K pathway result in a different composition of the breast tumor microenvironment. Here we present the retrospective analysis of a prospective randomized trial in ER-positive breast cancer on the prognostic and predictive value of specific tumor-associated lymphocytes in the context of PI3K alterations. METHODS: We included 563 ER-positive tumors from a multicenter trial for stage I to III postmenopausal breast cancer patients, who were randomized to tamoxifen or no adjuvant therapy. The amount of CD8-, CD4-, and FOXP3-positive cells was evaluated by immunohistochemistry and quantified by imaging-analysis software. We analyzed the associations between PIK3CA hotspot mutations, PTEN expression, phosphorylated proteins of the PI3K and MAPK pathway (p-AKT, p-ERK1/2, p-4EBP1, p-p70S6K), and recurrence-free interval after adjuvant tamoxifen or no adjuvant treatment. RESULTS: CD8-positive lymphocytes were significantly more abundant in PIK3CA-mutated tumors (OR = 1.65; 95% CI 1.03-2.68). While CD4 and FOXP3 were not significantly associated with prognosis, patients with tumors classified as CD8-high had increased risk of recurrence (HR = 1.98; 95% CI 1.14-3.41; multivariable model including PIK3CA status, treatment arm, and other standard clinicopathological variables). Lymphocytes were more often present in tumors with increased PI3K downstream phosphorylation. This was most pronounced for FOXP3-positive cells. CONCLUSION: These exploratory analyses of a prospective trial in luminal breast cancer suggest high CD8 infiltration is associated with unfavorable outcome and that PI3K pathway alterations might be associated with the composition of the tumor microenvironment.
Assuntos
Biomarcadores Tumorais , Suscetibilidade a Doenças , Neoplasias/etiologia , Neoplasias/metabolismo , Receptores de Estrogênio/metabolismo , Suscetibilidade a Doenças/imunologia , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Perfilação da Expressão Gênica , Humanos , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/metabolismo , Linfócitos do Interstício Tumoral/patologia , Mutação , Estadiamento de Neoplasias , Neoplasias/mortalidade , Neoplasias/patologia , Fosfatidilinositol 3-Quinase/genética , Fosfatidilinositol 3-Quinase/metabolismo , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Subpopulações de Linfócitos T/patologia , TranscriptomaRESUMO
BACKGROUND: The phosphatidylinositol-3-kinase (PI3K) and/or mitogen-activated protein kinase (MAPK) pathways are frequently activated in breast cancer which can result in antioestrogen resistance. Single protein markers failed to be introduced into clinical practice. We, therefore, aimed to find a better read-out of activation of the PI3K and MAPK pathways in ER+/HER2- breast cancer. Assessment of seven PI3K/MAPK proteins might better reflect pathway activation and distinguish patients without adjuvant tamoxifen benefit. METHODS: Tumour blocks were recollected from 293 primary postmenopausal ER+/HER2- breast cancer patients randomised between tamoxifen and no adjuvant therapy. PTEN, p-AKT(Thr308), p-AKT(Ser473), p-p70S6K, p-4EBP1, p-ERK1/2 and p-S6RP expression was assessed by immunohistochemistry followed by unsupervised hierarchical clustering. The primary endpoint was recurrence-free interval. Multivariate Cox models were used to assess tamoxifen benefit. A classification tool was developed based on protein expression profile. RESULTS: Subgroups were identified with preferentially activated (A) and preferentially not activated (N) proteins. Patients in group N derived significant benefit from tamoxifen (multivariate hazard ratio (HR) = 0.23, p = 0.000101), while patients from group A did not (multivariate HR = 1.37, p = 0.64), p for interaction 0.020. Our generated classification tool confirmed these results (p for interaction 0.024). CONCLUSIONS: Hierarchical clustering of seven PI3K/MAPK proteins reflects pathway activation and can guide treatment decisions in primary ER+/HER2- postmenopausal breast cancer patients.