Circadian Influences on Chemotherapy Efficacy in a Mouse Model of Brain Metastases of Breast Cancer

Chemotherapy is more effective in the treatment of peripheral tumors than brain metastases, likely reflecting the reduced ability of chemotherapy to cross the blood-brain barrier (BBB) and blood-tumor barrier at efficacious concentrations. Recent studies demonstrate circadian regulation of the BBB. Thus, we predicted that optimally timed chemotherapy would increase anti-tumor efficacy in a model of brain metastases of breast cancer (BMBC). First, we characterized novel daily alterations in BBB permeability to a commonly used chemotherapeutic, 14C-paclitaxel, within BMBC following injections given at four time points across the day. Peak and trough 14C-paclitaxel concentrations within BMBC occurred during the mid-dark phase and at the beginning of the light phase, respectively. Notably, chemotherapy injections during the dark phase increased cell death within BMBC and delayed onset of neurological symptoms relative to injections during the light phase. These data provide strong evidence for the beneficial effects of chrono-chemotherapy for the treatment of BMBC.

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THER-12. PRECLINICAL EVALUATION OF NERATINIB PLUS T-DM1 IN ORTHOTOPIC PDX MODELS OF HER2-POSITIVE BREAST CANCER BRAIN METASTASES

Neuro-Oncology Advances ◽

10.1093/noajnl/vdz014.055 ◽

2019 ◽

Vol 1 (Supplement_1) ◽

pp. i13-i13

Author(s):

Jing Ni ◽

Yanzhi Wang ◽

Irmina Diala ◽

Sheheryar Kabraji ◽

Rachel Freedman ◽

...

Keyword(s):

Breast Cancer ◽

Brain Metastases ◽

Tumor Growth ◽

Kinase Inhibitor ◽

Combined Treatment ◽

Single Agent ◽

Her2 Positive ◽

Time Points ◽

Breast Cancer Brain Metastases ◽

Pdx Models

Abstract Breast cancer brain metastases (BCBM) are a major cause of morbidity and mortality, despite multimodal management including surgery, radiotherapy, and systemic therapies. There is an urgent need to develop novel, efficacious alternatives. Neratinib is an orally bioavailable, irreversible pan-HER tyrosine kinase inhibitor that is FDA-approved in the extended adjuvant treatment setting for HER2-positive, early breast cancer (NCT00878709). Ado-trastuzumab emtansine (T-DM1) is an antibody-drug conjugate with reported single-agent activity against HER2-positive BCBM. Here, we used HER2-positive orthotopic patient derived xenograft (PDX) models of BCBM to test if combining neratinib with T-DM1 could improve tumor response. PDX cells are labelled with luciferase to allow tumor growth measurement in vivo. We found that neratinib is able to reduce phosphorylated HER2 in an orthotopic PDX tumor derived from HER2-positive BCBM, indicating that neratinib can cross the BBB and inhibit HER2 activation in BCBM PDX tissues. However, in both HER2-positive DF-BM354 and DF-BM355 PDX models, single agent neratinib did not block orthotopic tumor growth compared to vehicle control as monitored by bioluminescence measurements. In contrast, combined treatment of neratinib with T-DM1 significantly reduced tumor growth compared to single agent treatment with neratinib or T-DM1 at earlier time points in both models. At later time points, the combined treatment is comparable to T-DM1 alone in DF-BM354 model, but significantly prolong the survival of mice bearing DF-BM355 tumors. These data warrant further testing of neratinib alone and in combination with T-DM1 in additional BCBM PDX models to better understand drivers of resistance and susceptibility to HER2-inhibitors in HER2-positive BCBMs. Furthermore, they support the launch of a prospective clinical trial (NCT01494662) to test the efficacy and tolerability of T-DM1 in combination with neratinib in patients with progressive HER2-positive BCBM.

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The Cytotoxic Effect of Ethanol Extract of Momordica Charantia, Kuguacin-J and Cisplatin on Healthy MCF-10A and MCF-7 and MDAMB-231 Breast Cancer Cell Lines in Vitro

10.21203/rs.3.rs-615397/v1 ◽

2021 ◽

Author(s):

Chahinez Houacine ◽

Jaipaul Singh ◽

Raphael Singh ◽

Karishma Jeeboo ◽

Abdullah Adil Ansari ◽

...

Keyword(s):

Breast Cancer ◽

Cell Death ◽

Cell Viability ◽

Cell Lines ◽

Caspase 3 ◽

Ethanol Extract ◽

Momordica Charantia ◽

High Dose ◽

Time Points ◽

Mcf 7

Abstract Traditional medicines, derived from plants, could present alternative treatment strategy for cancer therapy. One such plant is Momordica charantia (MC) which possesses anti-carcinogenic properties. This study investigated the anticancer effect of an ethanol extract of MC fruit, Kuguacin-J (K-J), an isolated compound from the leaves of MC and cisplatin, either alone or combination on healthy MCF-10A mammary cells and compared with breast cancer MCF-7 and MDAMB-231 cell lines. Cell viability was tested using 8 μg/mL and 80 μg/mL doses of MC extract, K-J and cisplatin individually or combined for 24 and 48 hours. Caspase-3- activity was measured in MCF-7 and MDA-MB-231 cells using established methods. The results revealed that MC extract and K-J had no effect on healthy MCF-10A cell viability as compared to cisplatin which induced dose and time-dependent cell death. Similarly, treatment of MCF-7 cells with cisplatin induced cell death at high concentration at both the time points, while MC extract and K-J only induce MCF-7 cell death at high dose after 48 hours only. During combination therapy, both doses of cisplatin enhanced MCF-7 cell death when combined with MC extract or K-J after 24 and 48 hours. In MDAMB-231 cells, the three drugs, either alone or combined, evoked significant cell death at both the doses and time points. All three drugs, at high dose, elicited significant increase in caspase-3- activity in MCF-7 and MDA-MB-231 cells as compared to untreated cells. The results revealed that either MC extract or K-J alone or combined with cisplatin, can elicit significant increase in cell death and caspase–3-activity in MCF-7 and MDA-MB-231cells as compared to untreated cells.

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