scholarly journals Relationship between stemness and transcriptionally-inferred PI3K activity in human breast cancer

2020 ◽  
Author(s):  
Ralitsa R. Madsen ◽  
Oscar M. Rueda ◽  
Xavier Robin ◽  
Carlos Caldas ◽  
Robert K. Semple ◽  
...  

ABSTRACTThe development of reliable, prognostically informative molecular tests to direct targeted cancer therapy is a major challenge. In 2019, the PI3Kα inhibitor alpelisib was approved for the treatment of advanced breast cancer, in combination with the oestrogen receptor degrader fulvestrant, with some evidence for improved therapeutic response in patients classified as having tumours which were positive for mutation in PIK3CA, the gene encoding PI3Kα. Using human pluripotent stem cells, we recently demonstrated that the PIK3CAH1047R oncogenic hotspot variant shows marked PIK3CA allele dose-dependent activation of PI3K signalling and induction of self-sustained stemness. Together with recent discoveries of multi-copy and double-cis PIK3CA mutations in human cancers, this calls for a re-evaluation of the PIK3CA genotype-phenotype relationship and the current use of binary stratification by PIK3CA mutation status. Using computational analyses, we thus investigated the relationship between PIK3CA mutational status, PI3K activity/signalling strength and stemness. Stemness and PI3K activity scores were calculated using open-source methods and well-established transcriptional signatures. We report that a high PI3K pathway activity score, but not the presence of PIK3CA mutation per se, predicts increased breast cancer dedifferentiation and higher stemness, correlating with reduced overall survival. Our data (1) corroborate reports that the presence of a PIK3CA mutation per se does not predict high PI3K pathway activation or poor prognosis; (2) suggest that stratification of breast cancer for PI3K-based therapy might benefit from the use of a PI3K pathway activity score rather than binary PIK3CA mutation status alone; (3) suggest that combination of PI3K pathway inhibitors with differentiation-promoting treatments warrants evaluation in aggressive breast cancers with high PI3K activity and stemness scores.

2021 ◽  
Vol 1 (3) ◽  
pp. 140-147
Author(s):  
Cynthia Villarreal-Garza ◽  
Ana S. Ferrigno ◽  
Alejandro Aranda-Gutierrez ◽  
Paul H. Frankel ◽  
Nora H. Ruel ◽  
...  

The presence of BRCA pathogenic variants (PV) in triple-negative breast cancer (TNBC) is associated with a distinctive genomic profile that makes the tumor particularly susceptible to DNA-damaging treatments. However, patients with BRCA PVs can develop treatment resistance through the appearance of reversion mutations and restored BRCA expression. As copy-number variants (CNV) could be less susceptible to reversion mutations than point mutations, we hypothesize that carriers of BRCA CNVs may have improved survival after treatment compared with carriers of other BRCA PVs or BRCA wild-type. Women diagnosed with stage I–III TNBC at ≤50 years at a cancer center in Mexico City were screened for BRCA PVs using a recurrent PV assay (HISPANEL; 77% sensitivity). Recurrence-free survival (RFS) and overall survival (OS) were compared according to the mutational status. Among 180 women, 17 (9%) were carriers of BRCA1 ex9–12del CNVs and 26 (14%) of other BRCA PVs. RFS at ten years for the whole cohort was 79.2% [95% confidence interval (CI), 72.3–84.6], with no significant differences according to mutational status. 10-year OS for the entire cohort was 85.3% (95% CI, 78.7–90.0), with BRCA CNV carriers demonstrating numerically superior OS rates other PV carriers and noncarriers (100% vs. 78.6% and 84.7%; log-rank P = 0.037 and P = 0.051, respectively). This study suggests that BRCA1 ex9–12del CNV carriers with TNBC may have a better OS, and supports the hypothesis that the genotype of BRCA PVs may influence survival by limiting treatment resistance mediated by reversion mutations among CNV carriers. Significance: Large CNV BRCA carriers in a cohort of young Mexican patients with TNBC had superior OS rates than carriers of other BRCA pathogenic variants (i.e., small indels or point mutations). We hypothesize that this is due to the resistance of CNVs to reversion mutations mediating resistance to therapy. If validated, these findings have important prognostic and clinical treatment implications for BRCA-associated breast cancers.


Breast Care ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 355-365
Author(s):  
Julian Puppe ◽  
Tabea Seifert ◽  
Christian Eichler ◽  
Henryk Pilch ◽  
Peter Mallmann ◽  
...  

Background: Breast cancer is a very heterogeneous disease and luminal breast carcinomas represent the hormone receptor-positive tumors among all breast cancer subtypes. In this context, multigene signatures were developed to gain further prognostic and predictive information beyond clinical parameters and traditional immunohistochemical markers. Summary: For early breast cancer patients these molecular tools can guide clinicians to decide on the extension of endocrine therapy to avoid over- and undertreatment by adjuvant chemotherapy. Beside the predictive and prognostic value, a few genomic tests are also able to provide intrinsic subtype classification. In this review, we compare the most frequently used and commercially available molecular tests (OncotypeDX®, MammaPrint®, Prosigna®, EndoPredict®, and Breast Cancer IndexSM). Moreover, we discuss the clinical utility of molecular profiling for advanced breast cancer of the luminal subtype. Key Messages: Multigene assays can help to de-escalate systemic therapy in early-stage breast cancer. Only the Oncotype DX® and MammaPrint®test are validated by entirely prospective and randomized phase 3 trials. More clinical evidence is needed to support the use of genomic tests in node-positive disease. Recent developments in high-throughput sequencing technology will provide further insights to understand the heterogeneity of luminal breast cancers in early-stage and metastatic disease.


2006 ◽  
Vol 24 (16) ◽  
pp. 2437-2443 ◽  
Author(s):  
Lori J. Pierce ◽  
Albert M. Levin ◽  
Timothy R. Rebbeck ◽  
Merav A. Ben-David ◽  
Eitan Friedman ◽  
...  

Purpose We compared the outcome of breast-conserving surgery and radiotherapy in BRCA1/2 mutation carriers with breast cancer versus that of matched sporadic controls. Methods A total of 160 BRCA1/2 mutation carriers with breast cancer were matched with 445 controls with sporadic breast cancer. Primary end points were rates of in-breast tumor recurrence (IBTR) and contralateral breast cancers (CBCs). Median follow-up was 7.9 years for mutation carriers and 6.7 years for controls. Results There was no significant difference in IBTR overall between carriers and controls; 10- and 15-year estimates were 12% and 24% for carriers and 9% and 17% for controls, respectively (hazard ratio [HR], 1.37; P = .19). Multivariate analyses for IBTR found BRCA1/2 mutation status to be an independent predictor of IBTR when carriers who had undergone oophorectomy were removed from analysis (HR, 1.99; P = .04); the incidence of IBTR in carriers who had undergone oophorectomy was not significantly different from that in sporadic controls (P = .37). CBCs were significantly greater in carriers versus controls, with 10- and 15-year estimates of 26% and 39% for carriers and 3% and 7% for controls, respectively (HR, 10.43; P < .0001). Tamoxifen use significantly reduced risk of CBCs in mutation carriers (HR, 0.31; P = .05). Conclusion IBTR risk at 10 years is similar in BRCA1/2 carriers treated with breast conservation surgery who undergo oophorectomy versus sporadic controls. As expected, CBCs are significantly increased in carriers. Although the incidence of CBCs was significantly reduced in mutation carriers who received tamoxifen, this rate remained significantly greater than in controls. Additional strategies are needed to reduce contralateral cancers in these high-risk women.


2021 ◽  
Vol 22 (21) ◽  
pp. 11878
Author(s):  
Ajay Dhakal ◽  
Luna Acharya ◽  
Ruth O’Regan ◽  
Shipra Gandhi ◽  
Carla Falkson

Derangement of the phosphatidylinositol-3 kinase (PI3K) pathway is implicated in several subtypes of breast cancers. Mutation or upregulation of PI3K enhances cancer cells’ survival, proliferation, and ability to metastasize, making it an attractive molecular target for systemic therapy. PI3K has four isoforms, and several drugs targeting individual isoforms or pan-PI3K have been or are currently being investigated in clinical trials. However, the search for an effective PI3K inhibitor with a robust therapeutic effect and reasonable safety profile for breast cancer treatment remains elusive. This review focuses on the recently completed and ongoing clinical trials involving PI3K inhibitors as mono- or combination therapy in breast cancer. We review the salient findings of clinical trials, the therapeutic efficacy of PI3K inhibitors, and reported adverse effects leading to treatment discontinuation. Lastly, we discuss the challenges and potential opportunities associated with adopting PI3K inhibitors in the clinic.


2020 ◽  
Vol 12 ◽  
pp. 175883592097532
Author(s):  
Lorena Incorvaia ◽  
Daniele Fanale ◽  
Marco Bono ◽  
Valentina Calò ◽  
Alessia Fiorino ◽  
...  

Background: Several available data suggest the association between specific molecular subtypes and BRCA1/2 mutational status. Previous investigations showed the association between BRCA1/2 pathogenic variants (PVs) in specific genomic regions and phenotypic variations of cancer relative risk, while the role of PV type and location in determining the breast cancer (BC) phenotypic features remains still unclear. The aim of this research was to describe the germline BRCA1/2 PVs in triple-negative breast cancer (TNBC) versus luminal-like BC and their potential leverage on BC phenotype. Patients & methods: We retrospectively collected and analyzed all clinical information of 531 patients with BC genetically tested for germline BRCA1/2 PVs by Next-Generation Sequencing analysis at University Hospital Policlinico “P. Giaccone” of Palermo (Sicily) from January 2016 to February 2020. Results: Our results corroborate the evidence that BRCA1-related tumors often have a profile which resembles the TNBC subtype, whereas BRCA2-associated tumors have a profile that resembles luminal-like BC, especially the Luminal B subtype. Interestingly, our findings suggest that the PVs identified in TNBC were not largely overlapping with those in luminal-like tumors. Differences in the frequency of two PVs potentially associated with different molecular tumor subtypes were observed. BRCA1-633delC was detected with relatively higher prevalence in patients with TNBC, whereas BRCA2-1466delT was found mainly in Luminal B tumors, but in no TNBC patient. Conclusion: Future studies examining the type and location of BRCA1/2 PVs within different molecular subtypes are required to verify our hypothesis and could provide an interesting insight into the complex topic of genotype–phenotype correlations. Additionally, a more in-depth understanding of the potential correlations between BRCA PVs and clinical and phenotypic features of hereditary BC syndrome patients could be the key to develop better strategies of prevention and surveillance in BRCA-positive carriers without disease.


2020 ◽  
Author(s):  
Márcia A. Inda ◽  
Paul van Swinderen ◽  
Anne van Brussel ◽  
Cathy B. Moelans ◽  
Wim Verhaegh ◽  
...  

AbstractBackgroundTargeted drug treatment aims to block tumor driving signaling pathways, and is generally based on analysis of one primary tumor (PT) biopsy. Phenotypic heterogeneity within primary and between primary and metastatic lesions was investigated.MethodsActivity of androgen and estrogen receptor, PI3K-FOXO, Hedgehog, TGFβ, and Wnt signaling pathways was measured in breast cancer samples using a novel mRNA-based assay platform. Macro-scale heterogeneity analysis was performed on multiple spatially distributed PT tissue blocks from 17 luminal A-like, 9 luminal B-like, and 9 ER-negative primary breast cancers; micro-scale heterogeneity analysis was performed on four “quadrant” samples of a single tissue block of respectively 9, 4, and 4 matched PT. Samples from 6 PT with matched lymph node (LN, n=23) and 9 PT with distant metastatic sites (DS, n=12) were analyzed. Statistical variance analysis was performed with linear mixed models. A “checkerboard” model was introduced to explain the observed heterogeneity in PT.ResultsWithin PT, macro-scale heterogeneity in signaling pathway activity was similar to micro-scale heterogeneity, with a possible exception of the PI3K pathway. Variation was significantly higher on microscale for Hedgehog and TGFβ pathways. While pathway activity scores correlated significantly between different locations in the PT, positive correlations decreased between PT and LN, and even more between PT and DS metastases, including the emergence of a negative correlation for the ER pathway.ConclusionWith a possible exception of the PI3K pathway, variation in signaling pathway activity within a single PT tissue block was generally representative for the whole PT, but not for DS or LN metastases. The higher variation in TGFβ and HH pathway activity on microscale suggested the presence of multiple small cancer cell clones. While analysis of multiple sub-samples of a single biopsy block may be sufficient to predict PT response to some targeted therapies, such as hormonal therapy, metastatic breast cancer treatment requires analysis of metastatic biopsies. The findings on phenotypic intra-tumor heterogeneity are compatible with currently emerging ideas on a Big Bang type of cancer evolution.


2021 ◽  
Vol 11 (5) ◽  
pp. 524-538
Author(s):  
Anirban Roy ◽  
Indira Chakraborty ◽  
Aniruddha Banerji

Breast cancer is one of the most prevalent forms of cancer in women both globally and in India. Although breast cancer is characterized by different molecular subtypes, a majority of breast cancers appear to have mutations in the phosphatidylinositol 3′ kinase (PI3K)/ protein kinase B (Akt) pathway. Dysregulation of the PI3K/ Akt pathway in breast cancers plays important roles in promoting tumour growth, proliferation and invasion. Targeting PI3K mediated signalling cascades could be therefore of value for breast cancer treatment. Studies with synthetic inhibitors of the PI3K/ Akt pathway have yielded positive results but the efficacy shown by many of these inhibitors appear to be compromised by deleterious side effects. An alternative to syn-thetic inhibitors is the use of natural phytochemical compounds with anti-tumorigenic potential like apigenin, pomolic acid, resveratrol and its deriva-tives, curcumin, epigallocatechin-3 gallate and thymoquinone as potential inhibitors of PI3K/Akt signalling in breast cancer and such a strategy could lead to lesser side effects and a lower treatment cost. The current study ex-amines the importance of the PI3K pathway in breast cancer and discusses how regulation of aberrant signalling through this pathway by natural com-pounds could play an important role in breast cancer therapy.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e13549-e13549
Author(s):  
Rosane Oliveira Sant'Ana ◽  
Isabelle Joyce de Lima Silva-Fernandes ◽  
Maria Claudia dos Santos Luciano ◽  
Paulo Goberlanio de Barros Silva ◽  
Marcos Venício Alves Lima

e13549 Background: Local Advanced Breast Cancer (LABC) is associated with high risk of death. NAC is a safe and effective approach for these populations. pCR is a proven prognostic factor in several studies of NAC. HBOC is associated to high risk of breast cancer usually in young age and especially for BRCA1 mutations with a basal phenotype. The aim of this study was to evaluate the influence of BRCA mutational status on frequence of pCR. Methods: this is part of a retrospective, observational study of prevalence of HBOC among patients admitted for cancer therapy in our institution. Since August, 2018 over 300 pte suspected for HBOC (by NCCN criteria) have been screened for NGS with a 31-gene painel. Statistical analysis performed Person X2/Fisher and logistic regression ( p< 0.05; SPSS 20.0). Results: Most pte were women (80%), with median age of 38y (22-72y), most tumors were (80%) stage III, Luminal B (23%) and TNBC (36%). Pathogenic mutations were identified in 34%(n = 28) of the sample ( BRCA1 50%, BRCA2 16.7%, PALB2 16.7%, follow by TP53, PMS2, XRCC2, MUTYH, BARD1 and ATM with 2.8% each).The majority of patients had more than 1 NCCN criteria: age < 45y (83%), family member with BC < 50y (24%) or TNBC (33%) the most common. TNBC tumors had stronger association with germline mutation ( p< 0.001). Regarding response rate there were 13 stable disease (SD), 5 progressive disease (PD), 43 pCR and 39 pathological partial response (pPR). There were no differences in pRC among mutated or no mutated pte, p= 0,170. However, among mutated TNBC there were strong correlation with more pCR, p< 0,006. There was no difference on pCR rate related to mutation status (BRCA vs Non-BRCA), p = 0,84. Conclusions: the present study corroborates other data about the impact of germline mutation status over pCR after NAC for LABC, except for mutated TNBC population, whose seems to be more NAC sensitive.


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