Keratins are the intermediate filament (IF)-forming proteins of epithelial cells. Since their initial characterization almost 30 years ago, the total number of mammalian keratins has increased to 54, ...including 28 type I and 26 type II keratins. Keratins are obligate heteropolymers and, similarly to other IFs, they contain a dimeric central α-helical rod domain that is flanked by non-helical head and tail domains. The 10-nm keratin filaments participate in the formation of a proteinaceous structural framework within the cellular cytoplasm and, as such, serve an important role in epithelial cell protection from mechanical and non-mechanical stressors, a property extensively substantiated by the discovery of human keratin mutations predisposing to tissue-specific injury and by studies in keratin knockout and transgenic mice. More recently, keratins have also been recognized as regulators of other cellular properties and functions, including apico-basal polarization, motility, cell size, protein synthesis and membrane traffic and signaling. In cancer, keratins are extensively used as diagnostic tumor markers, as epithelial malignancies largely maintain the specific keratin patterns associated with their respective cells of origin, and, in many occasions, full-length or cleaved keratin expression (or lack there of) in tumors and/or peripheral blood carries prognostic significance for cancer patients. Quite intriguingly, several studies have provided evidence for active keratin involvement in cancer cell invasion and metastasis, as well as in treatment responsiveness, and have set the foundation for further exploration of the role of keratins as multifunctional regulators of epithelial tumorigenesis.
Pembrolizumab for Early Triple-Negative Breast Cancer Schmid, Peter; Cortes, Javier; Pusztai, Lajos ...
New England journal of medicine/The New England journal of medicine,
02/2020, Letnik:
382, Številka:
9
Journal Article
Recenzirano
Odprti dostop
The addition of pembrolizumab to platinum-based neoadjuvant chemotherapy significantly increased the percentage of patients with a pathological complete response among patients with locally advanced ...triple-negative breast cancer. Side effects of the immunotherapy were added to the usual toxic effects of chemotherapy, but most patients completed planned treatment.
Treatment options for previously treated metastatic triple-negative breast cancer (mTNBC) are limited. In cohort A of the phase II KEYNOTE-086 study, we evaluated pembrolizumab as second or later ...line of treatment for patients with mTNBC.
Eligible patients had centrally confirmed mTNBC, ≥1 systemic therapy for metastatic disease, prior treatment with anthracycline and taxane in any disease setting, and progression on or after the most recent therapy. Patients received pembrolizumab 200 mg intravenously every 3 weeks for up to 2 years. Primary end points were objective response rate in the total and PD-L1–positive populations, and safety. Secondary end points included duration of response, disease control rate (percentage of patients with complete or partial response or stable disease for ≥24 weeks), progression-free survival, and overall survival.
All enrolled patients (N = 170) were women, 61.8% had PD-L1–positive tumors, and 43.5% had received ≥3 previous lines of therapy for metastatic disease. ORR (95% CI) was 5.3% (2.7–9.9) in the total and 5.7% (2.4–12.2) in the PD-L1–positive populations. Disease control rate (95% CI) was 7.6% (4.4–12.7) and 9.5% (5.1–16.8), respectively. Median duration of response was not reached in the total (range, 1.2+–21.5+) and in the PD-L1–positive (range, 6.3–21.5+) populations. Median PFS was 2.0 months (95% CI, 1.9–2.0), and the 6-month rate was 14.9%. Median OS was 9.0 months (95% CI, 7.6–11.2), and the 6-month rate was 69.1%. Treatment-related adverse events occurred in 103 (60.6%) patients, including 22 (12.9%) with grade 3 or 4 AEs. There were no deaths due to AEs.
Pembrolizumab monotherapy demonstrated durable antitumor activity in a subset of patients with previously treated mTNBC and had a manageable safety profile.
ClinicalTrials.gov, NCT02447003
Standard first-line treatment of metastatic triple-negative breast cancer (mTNBC) is chemotherapy. However, outcomes are poor, and new treatment options are needed. In cohort B of the phase II ...KEYNOTE-086 study, we evaluated pembrolizumab as first-line therapy for patients with PD-L1-positive mTNBC.
Eligible patients had centrally confirmed mTNBC, no prior systemic anticancer therapy for metastatic disease, measurable disease at baseline per RECIST v1.1 by central review, no radiographic evidence of central nervous system metastases, and a tumor PD-L1 combined positive score ≥1. Patients received pembrolizumab 200 mg intravenously every 3 weeks for up to 2 years. The primary end point was safety. Secondary end points included objective response rate, disease control rate (percentage of patients with complete or partial response or stable disease for ≥24 weeks), duration of response, progression-free survival and overall survival.
All 84 patients enrolled were women, and 73 (86.9%) received prior (neo)adjuvant therapy. Fifty-three (63.1%) patients had treatment-related adverse events (AEs), including 8 patients (9.5%) with grade 3 severity; no patients experienced grade 4 AEs or died because of treatment-related AEs. Four patients had a complete response and 14 had a partial response, for an objective response rate of 21.4% (95% CI 13.9–31.4). Of the 13 patients with stable disease, 2 had stable disease lasting ≥24 weeks, for a disease control rate of 23.8% (95% CI 15.9–34.0). At data cut-off, 8 of 18 (44.4%) responses were ongoing, and median duration of response was 10.4 months (range 4.2 to 19.2+). Median progression-free survival was 2.1 months (95% CI 2.0–2.2), and median overall survival was 18.0 months (95% CI 12.9–23.0).
Pembrolizumab monotherapy had a manageable safety profile and showed durable antitumor activity as first-line therapy for patients with PD-L1-positive mTNBC.
ClinicalTrials.gov, NCT02447003.
The phase Ib KEYNOTE-173 study was conducted to assess the safety and preliminary antitumor activity of neoadjuvant chemotherapy plus pembrolizumab in high-risk, early-stage, non-metastatic ...triple-negative breast cancer (TNBC).
Six pembrolizumab plus chemotherapy regimens were evaluated (cohorts A–F). All cohorts received a pembrolizumab 200-mg run-in dose (cycle 1), then eight cycles of pembrolizumab in combination with a taxane with or without carboplatin for 12 weeks, and then doxorubicin and cyclophosphamide for an additional 12 weeks before surgery. Primary end points were safety and recommended phase II dose (RP2D); secondary end points were pathological complete response (pCR) rate, objective response rate, and event-free and overall survival. Exploratory end points were the relationship between outcome and potential biomarkers, such as tumor programmed death ligand 1 (PD-L1) expression (combined positive score) and stromal tumor-infiltrating lymphocyte levels (sTILs).
Sixty patients were enrolled between 18 February 2016, and 28 February 2017. Dose-limiting toxicities occurred in 22 patients, most commonly febrile neutropenia (n = 10 across cohorts). Four cohorts (B, C, D, F) did not meet the RP2D threshold; two cohorts did (A, E). The most common grade ≥3 treatment-related adverse event was neutropenia (73%). Immune-mediated adverse events and infusion reactions occurred in 18 patients (30%) and were grade ≥3 in six patients (10%). The pCR rate (ypT0/Tis ypN0) across all cohorts was 60% (range 49%–71%). Twelve-month event-free and overall survival rates ranged from 80% to 100% across cohorts (100% for four cohorts). Higher pre-treatment PD-L1 combined positive score, and pre- and on-treatment sTILs were significantly associated with higher pCR rates (P = 0.0127, 0.0059, and 0.0085, respectively).
Combination neoadjuvant chemotherapy and pembrolizumab for high-risk, early-stage TNBC showed manageable toxicity and promising antitumor activity. In an exploratory analysis, the pCR rate showed a positive correlation with tumor PD-L1 expression and sTIL levels.
ClinicalTrials.gov identifier: NCT02622074.
•Neoadjuvant pembrolizumab + chemotherapy showed no unexpected safety findings in patients with high-risk, early-stage TNBC.•Two chemotherapy regimens met the RP2D threshold: nab-paclitaxel 125 mg/m2 qw; paclitaxel 80 mg/m2 qw + carboplatin AUC5 q3w.•pCR rate (ypT0/Tis ypN0) across all cohorts was 60% and 12-month EFS and OS rates ranged from 80% to 100% across cohorts.•pCR rate showed positive correlation with tumor PD-L1 expression and stromal tumor-infiltrating lymphocyte levels.
Among patients who had mutations in
BRCA1
or
BRCA2
and were at high risk for disease progression, those who were assigned to a year of olaparib adjuvant therapy had 3-year invasive disease–free ...survival of 86%, as compared with 77% among those who were assigned to placebo. Few patients stopped olaparib owing to side effects.
Previous studies have shown that increased levels of the adaptor protein Sequestosome 1/p62 are observed in human breast cancers and significantly correlate with HER2 overexpression. However, the ...role of p62 in the pathophysiology of HER2-induced mammary tumorigenesis has not yet been investigated. In this study, we report that p62 facilitates HER2-mediated cell survival in both two-dimensional and three-dimensional cell culture and that HER2-induced cellular transformation requires p62, as well as NRF2, which is known to become stabilized by its release from Kelch-like ECH-associated protein 1 (KEAP1) via p62-KEAP1 interaction. In agreement with these results, genetic ablation of p62 delays HER2-induced mammary tumorigenesis in tumor cell allografts in nude mice, and in MMTV-Neu transgenic mice. We also report that ablation of p62 impairs AKT and β-catenin activation in association with PTEN (phosphatase and tensin homolog deleted on chromosome ten) accumulation, both in vitro and in vivo. Further in vivo studies suggest that loss of p62 also impairs NF-κB and NRF2 activation. Collectively, our results provide compelling evidence that p62 contributes to HER2-induced mammary tumorigenesis through multiple signaling pathways, including the PTEN/phosphoinositide-3-kinase/AKT axis, WNT/β-catenin signaling, the NF-κB pathway and the NRF2-KEAP1 axis, and offer novel insights into the potential role of p62 in the regulation of the tumor suppressor PTEN.
The Pak4 protein kinase, normally expressed at low level in the mammary gland, is commonly overexpressed in breast cancer. Overexpression of Pak4 transforms mouse mammary epithelial cells in vitro ...and renders these cells tumorigenic in athymic mice in vivo. Here we show that Pak4 is also required for oncogenic transformation of the human breast cancer cell line MDA-MB-231. These high Pak4-expressing human breast cancer cells form highly disorganized three-dimensional (3D) structures in vitro and readily give rise to orthotopic xenograft tumors in nude mice. We have found that when Pak4 levels are reduced, MDA-MB-231 cells exhibit decreased proliferation and migration in vitro, as well as gross restoration of normal 3D mammary acinar organization, the latter in association with a strong induction of apoptosis. Similarly, Pak4 knockdown suppresses MDA-MB-231 breast xenograft tumor formation in nude mice in vivo. These results indicate that Pak4 has a key role in the oncogenic transformation of breast cells.
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