We wanted to determine the prognosis and the phenotypic characteristics of hormone receptor-positive advanced breast cancer tumors harboring an ERBB2 mutation in the absence of a HER2 amplification.
...We retrospectively collected information from the American Association of Cancer Research-Genomics Evidence Neoplasia Information Exchange registry database from patients with hormone receptor-positive, HER2-negative, ERBB2-mutated advanced breast cancer. Phenotypic and co-mutational features, as well as response to treatment and outcome were compared with matched control cases ERBB2 wild type.
A total of 45 ERBB2-mutant cases were identified for 90 matched controls. The presence of an ERBB2 mutation was not associated with worse outcome determined by overall survival (OS) from first metastatic relapse. No significant differences were observed in phenotypic characteristics apart from higher lobular infiltrating subtype in the ERBB2-mutated group. ERBB2 mutation did not seem to have an impact in response to treatment or time-to-progression (TTP) to endocrine therapy compared with ERBB2 wild type. In the co-mutational analyses, CDH1 mutation was more frequent in the ERBB2-mutated group (FDR < 1). Although not significant, fewer co-occurring ESR1 mutations and more KRAS mutations were identified in the ERBB2-mutated group.
ERBB2-activating mutation was not associated with a worse OS from time of first metastatic relapse, or differences in TTP on treatment as compared with a series of matched controls. Although not significant, differences in coexisting mutations (CDH1, ESR1, and KRAS) were noted between the ERBB2-mutated and the control group.
Human epidermal growth factor receptor (EGFR) 2 (HER2) is overexpressed/amplified in about 25% of all breast cancers, and EGFR is overexpressed in up to 76% and amplified in up to 24% of ...triple-negative breast cancers (TNBC). Here, we aimed to identify inhibitors that may enhance the anti-tumor activity of neratinib for HER2+ breast cancer and TNBC. By conducting a non-biased high-throughput RNA interference screening, we identified PI3K/AKT/mTOR and MAPK as two potential inhibitory synergistic canonical pathways. We confirmed that everolimus (mTOR inhibitor) and trametinib (MEK inhibitor) enhances combinatorial anti-proliferative effects with neratinib under anchorage-independent growth conditions (p < 0.05). Compared to single agent neratinib, the combination therapies significantly enhanced tumor growth inhibition in both SUM190 HER2+ breast cancer (neratinib plus everolimus, 77%; neratinib plus trametinib, 77%; p < 0.0001) and SUM149 TNBC (neratinib plus everolimus, 71%; neratinib plus trametinib, 81%; p < 0.0001) xenograft models. Compared to single-agent neratinib, everolimus, or trametinib, both everolimus plus neratinib and trametinib plus neratinib significantly suppressed proliferation marker Ki67 and enhanced antitumor efficacy by activating the apoptosis pathway shown by increased Bim and cleaved-PARP expression. Taken together, our data justify new neratinib-based combinations for both HER2+ breast cancer and TNBC.
The irreversible ERBB1/2/4 inhibitor neratinib has been shown
to rapidly reduce the expression of ERBB1/2/4 and RAS proteins via autophagic/lysosomal degradation. We have recently demonstrated that ...neratinib and valproate interact to suppress the growth of 4T1 mammary tumors but had not defined whether the neratinib + valproate drug combination, in a mouse, had altered the biology of the 4T1 cells. Exposure of 4T1 mammary tumors to neratinib + valproate for three days resulted, two weeks later, in tumors that expressed less ERBB1, K-RAS, N-RAS, indoleamine-pyrrole 2,3-dioxygenase (IDO-1), ornithine decarboxylase (ODC) and had increased Class I MHCA expression. Tumors previously exposed to neratinib + valproate grew more slowly than those exposed to vehicle control and contained more CD8+ cells and activated NK cells. M1 but not M2 macrophage infiltration was significantly enhanced by the drug combination.
exposure of 4T1 tumor cells to neratinib + valproate variably reduced the expression of histone deacetylases 1-11.
, prior exposure of tumors to neratinib + valproate permanently reduced the expression of HDACs 1-3, 6 and 10. Combined knock down of HDACs 1/2/3 or of 3/10 rapidly reduced the expression IDO-1, and ODC and increased the expression of MHCA. H&E staining of normal tissues at animal nadir revealed no obvious cyto-architectural differences between control and drug-treated animals. We conclude that neratinib + valproate evolves 4T1 tumors to grow more slowly and to be more sensitive to checkpoint immunotherapy antibodies.
Lapatinib (L) plus trastuzumab (T), with endocrine therapy for estrogen receptor (ER)+ tumors, but without chemotherapy, yielded meaningful response in HER2+ breast cancer (BC) neoadjuvant trials. ...The irreversible/pan-HER inhibitor neratinib (N) has proven more potent than L. However, the efficacy of N+T in comparison to pertuzumab (P) + T or L + T (without chemotherapy) remains less studied. To address this, mice bearing HER2+ BT474-AZ (ER+) cell and BCM-3963 patient-derived BC xenografts were randomized to vehicle, N, T, P, N+T, or P+T, with simultaneous estrogen deprivation for BT474-AZ. Time to tumor regression/progression and incidence/time to complete response (CR) were determined. Changes in key HER pathway and proliferative markers were assessed by immunohistochemistry and western blot of short-term-treated tumors. In the BT474-AZ model, while all N, P, T, N + T, and P + T treated tumors regressed, N + T-treated tumors regressed faster than P, T, and P + T. Further, N + T was superior to N and T alone in accelerating CR. In the BCM-3963 model, which was refractory to T, P, and P + T, while N and N + T yielded 100% CR, N + T accelerated the CR compared to N. Ki67, phosphorylated (p) AKT, pS6, and pERK levels were largely inhibited by N and N + T, but not by T, P, or P + T. Phosphorylated HER receptor levels were also markedly inhibited by N and N + T, but not by P + T or L + T. Our findings establish the efficacy of combining N with T and support clinical testing to investigate the efficacy of N + T with or without chemotherapy in the neoadjuvant setting for HER2+ BC.
Purpose
The human epidermal growth factor receptor 2 (
ERBB2
) may harbour somatic mutations that drive breast tumorigenesis. Here, we study prevalence, tumour characteristics and disease outcome of
...ERBB2
mutations in a large unselected cohort of metastatic breast cancer (mBC) patients.
Methods
We retrospectively included all mBC patients with sufficient primary breast tumour, diagnosed between 2000 and 2015 (
n
= 775). Genomic DNA was subjected to a targeted-resequencing assay to identify hotspot mutations in exon 8, 17, 19, 20, and 21 of
ERBB2
. We studied demographics, tumour characteristics, median distant disease-free survival (DDFS), using a time-to-event analysis and time to progression (TTP) and overall survival (OS) upon metastasis, using Kaplan–Meier and log-rank statistics to assess differences between
ERBB2
-mutation statuses.
Results
ERBB2
mutations were observed in 1.8% of the samples (13/721). Patient and tumour characteristics were independent of
ERBB2
mutations. Luminal
ERBB2
-mutated (
ERBB2
mut
+
) cases (
n
= 5) had a shorter DDFS than
ERBB2
mut
−
cases (median DDFS 0.8 vs. > 4.0 years,
p
= 0.02). ER-positive
ERBB2
mut
+
patients who received an aromatase inhibitor (AI) as first-line treatment (stage IV disease) had a worse TTP vs.
ERBB2
mut
−
patients (
n
= 3 vs. 156; median TTP 103 vs. 311 days,
p
= 0.04). OS for all subtypes was lower for
ERBB2
mut
+
vs.
ERBB2
mut
−
cases (
n
= 11 vs. 669; median OS 1.1 vs. 2.3 years,
p
= 0.46).
Conclusion
ERBB2
mut
+
are rare in patients in whom mBC developed and no evidence was found for an association with specific types of BC or patient characteristics, although outcomes of
ERBB2
mut
+
carriers might be worse. The latter, however, needs to be validated in larger populations.
Cancers expressing mutant RAS are associated with a weaker response to chemotherapy and a shorter overall patient survival. We have demonstrated that the irreversible inhibitor of ERBB1/2/4, ...neratinib, inhibits ERBB1/2/4 and causes their internalization and autolysosomal degradation. Fellow-traveler membrane proteins with RTKs, including mutant K-/N-RAS, were also degraded. We discovered that the CDK4/6 inhibitor palbociclib increased autophagosome and then autolysosome levels in a time dependent fashion, did not reduce mTOR activity, and interacted with temsirolimus to kill. Neratinib and palbociclib interacted in a greater than additive manner to increase autophagosome and then autolysosome levels in a time dependent fashion, and to cause tumor cell killing. Killing required the expression of ATM and AMPKα, Beclin1 and ATG5, BAX and BAK and of AIF, but not of caspase 9. In some cells over-expression of BCL-XL was protective whereas in others it was ineffective. The lethality of neratinib + palbociclib was modestly enhanced by the PDE5 inhibitor sildenafil and strongly enhanced by the HDAC inhibitor sodium valproate. This was associated with K-RAS degradation and a greater than additive increase in autophagosome and autolysosome levels. Killing by the three-drug combination required ATM and AMPKα, and, to a greater extent, Beclin1 and ATG5. In vivo, valproate + palbociclib and neratinib + valproate + palbociclib interacted to suppress the growth of a carboplatin/paclitaxel resistant PDX ovarian tumors that express a mutant N-RAS. Our data support performing a future three-drug trial with these agents.
Purpose: AQ4N is a novel bioreductive prodrug under clinical investigation. Preclinical evidence shows that AQ4N penetrates deeply
within tumors and undergoes selective activation to form AQ4, a ...potent topoisomerase II inhibitor, in hypoxic regions of solid
tumors. This proof-of-principle, phase I study evaluated the activation, hypoxic selectivity, and safety of AQ4N in patients
with advanced solid tumors.
Experimental Design: Thirty-two patients with cancer (8 glioblastoma, 9 bladder, 8 head and neck, 6 breast, and 1 cervix) received a single 200
mg/m 2 dose of AQ4N before elective surgery. AQ4 and AQ4N levels in 95 tissues (tumor, healthy tissue) were assessed by liquid chromatography-tandem
mass spectrometry. Tissue sections were also analyzed for AQ4 fluorescence using confocal microscopy, and for expression of
the hypoxia-regulated glucose transporter, Glut-1.
Results: Activated AQ4 was detected in all tumor samples with highest levels present in glioblastoma (mean 1.2 μg/g) and head and
neck (mean 0.65 μg/g) tumors; 22 of 32 patients had tumor AQ4 concentrations ≥0.2 μg/g, levels previously shown to be active
in preclinical studies. In 24 of 30 tumor samples, AQ4 was detected at higher concentrations than in adjacent normal tissue
(tumor to normal ratio range 1.1-63.6); distant skin samples contained very low concentrations of AQ4 (mean 0.037 μg/g). Microscopic
evaluation of tumor sections revealed that AQ4 colocalized within regions of Glut-1+ hypoxic cells.
Conclusions: AQ4N was activated selectively in hypoxic regions in human solid tumors. Intratumoral concentrations of AQ4 exceeded those
required for activity in animal models and support the evaluation of AQ4N as a novel tumor-targeting agent in future clinical
studies.
The irreversible ERBB1/2/4 inhibitor, neratinib, down-regulates the expression of ERBB1/2/4 as well as the levels of MCL-1 and BCL-XL. Venetoclax (ABT199) is a BCL-2 inhibitor. At physiologic ...concentrations neratinib interacted in a synergistic fashion with venetoclax to kill HER2 + and TNBC mammary carcinoma cells. This was associated with the drug-combination: reducing the expression and phosphorylation of ERBB1/2/3; in an eIF2α-dependent fashion reducing the expression of MCL-1 and BCL-XL and increasing the expression of Beclin1 and ATG5; and increasing the activity of the ATM-AMPKα-ULK1 S317 pathway which was causal in the formation of toxic autophagosomes. Although knock down of BAX or BAK reduced drug combination lethality, knock down of BAX and BAK did not prevent the drug combination from increasing autophagosome and autolysosome formation. Knock down of ATM, AMPKα, Beclin1 or over-expression of activated mTOR prevented the induction of autophagy and in parallel suppressed tumor cell killing. Knock down of ATM, AMPKα, Beclin1 or cathepsin B prevented the drug-induced activation of BAX and BAK whereas knock down of BID was only partially inhibitory. A 3-day transient exposure of established estrogen-independent HER2 + BT474 mammary tumors to neratinib or venetoclax did not significantly alter tumor growth whereas exposure to neratinib + venetoclax caused a significant 7-day suppression of growth by day 19. The drug combination neither altered animal body mass nor behavior. We conclude that venetoclax enhances neratinib lethality by facilitating toxic BH3 domain protein activation via autophagy which enhances the efficacy of neratinib to promote greater levels of cell killing.
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