Potential role of pemetrexed in metastatic breast cancer patients pre-treated with anthracycline or taxane

Sequential Delivery of Novel Triple Drug Combination via Crosslinked Alginate/Lactoferrin Nanohybrids for Enhanced Breast Cancer Treatment

While breast cancer remains a global health concern, the elaboration of rationally designed drug combinations coupled with advanced biocompatible delivery systems offers new promising treatment venues. Herein, we repurposed rosuvastatin (RST) based on its selective tumor apoptotic effect and combined it with the antimetabolite pemetrexed (PMT) and the tumor-sensitizing polyphenol honokiol (HK). This synergistic three-drug combination was incorporated into protein polysaccharide nanohybrids fabricated by utilizing sodium alginate (ALG) and lactoferrin (LF), inspired by the stealth property of the former and the cancer cell targeting capability of the latter. ALG was conjugated to PMT and then coupled with LF which was conjugated to RST, forming core shell nanohybrids into which HK was physically loaded, followed by cross linking using genipin. The crosslinked HK-loaded PMT-ALG/LF-RST nanohybrids exhibited a fair drug loading of 7.86, 5.24 and 6.11% for RST, PMT and HK, respectively. It demonstrated an eight-fold decrease in the IC50 compared to the free drug combination, in addition to showing an enhanced cellular uptake by MCF-7 cells. The in vivo antitumor efficacy in a breast cancer-bearing mouse model confirmed the superiority of the triple cocktail-loaded nanohybrids. Conclusively, our rationally designed triple drug-loaded protein/polysaccharide nanohybrids offer a promising, biocompatible approach for an effective breast tumor suppression.

Rapid Determination of Pemetrexed Concentration and Distribution in Human Breast Cancer Cells (McF-7) Based on UHPLC-MS/MS

Cell is the basic unit of structure and function of all living bodies. The study of intracellular drug concentration distribution is helpful to understand the drug efficacy of target site. Pemetrexed is a new multitarget folate antagonist with pyrrolidine group as its core structure. An ultra high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method was developed for rapid quantification of pemetrexed concentration in human breast cancer cells (MCF-7). Sample pretreatment was completed by protein precipitation using methanol. The optimized chromatographic separation was achieved on a ZORBAX SB-C18 column (2.1 × 150 mm, 3.5 μm). The column was equilibrated with initial mobile phase and eluted under gradient phases containing 0.1% formic acid in water (phase A) and in acetonitrile (phase B). The gradient program started at 5% B, increased to 95% B in 2 min, and then held at 95% B for 1.5 min. The linear range of pemetrexed in cells and nucleus was 2.0–200.0 ng/mL, while in the medium sample it was 50.0–5000.0 ng/ml, and the correlation coefficients were all greater than 0.99. The recovery was 47.50–67.55% (2.0–200.0 ng/mL) and 82.72–97.15% (50.0–5000.0 ng/mL), and the matrix effect was 98.10–100.62% (2.0–200.0 ng/mL) and 89.78–97.65% (50.0–5000.0 ng/mL). Interday precision and intraday precision (RSD%) were less than 15.0% (for LLOQ, less than 20%), and accuracy (RE%) was within ±15%; the deviation of stability was within ±15%, all meeting the requirements of biological sample analysis. The results of intracellular samples showed that the concentration of pemetrexed reached its peak at 3 h after administration. The concentration of pemetrexed in the nucleus continued to increase 2 h after administration and may have reached the maximum concentration at 6 h.

Effects of folic acid withdrawal on transcriptomic profiles in murine triple-negative breast cancer cell lines

We have previously shown that withdrawal of folic acid led to metabolic reprogramming and a less aggressive phenotype in a mouse cell model of triple-negative breast cancer (TNBC). Herein, we evaluate the effects of folic acid withdrawal on transcriptomic profiles in these cells. Murine cell lines were originally derived from a pool of spontaneous mammary tumors grown in MMTV-Wnt1 transgenic mice. Based on their differential molecular characteristics and metastatic potential, these cell lines were previously characterized as non-metastatic epithelial (E-Wnt), non-metastatic mesenchymal (M-Wnt) and metastatic mesenchymal (metM-Wnt^liver) cells. Using custom two-color 180K Agilent microarrays, we have determined gene expression profiles for three biological replicates of each subtype kept on standard medium (2.2 μM folic acid) or folic acid-free medium for 72 h. The analyses revealed that more genes were differentially expressed upon folic acid withdrawal in M-Wnt cells (1884 genes; Benjamini-Hochberg-adjusted P-value <0.05) compared to E-Wnt and metM-Wnt^liver cells (108 and 222 genes, respectively). Pathway analysis has identified that type I interferon signaling was strongly affected by folic acid withdrawal, with interferon-responsive genes consistently being upregulated upon folic acid withdrawal in M-Wnt cells. Of note, repressed interferon signaling has been established as one of the characteristics of aggressive human TNBC, and hence reactivation of this pathway may be a promising therapeutic approach. Overall, while our study indicates that the response to folic acid withdrawal varies by molecular subtype and cellular phenotype, it also underscores the necessity to further investigate one-carbon metabolism as a potential therapeutic means in the treatment of advanced TNBC.

Lobaplatin-based regimens outperform cisplatin for metastatic breast cancer after anthracyclines and taxanes treatment

The goal of this study was to assess the antitumor efficacy and safety of lobaplatin-based regimens as the second line of treatment in patients with metastatic breast cancer (MBC) resistant to anthracyclines and taxanes, compared with that of cisplatin-based regimens. During August 2012 to April 2015, 87 patients who received lobaplatin-based regimens or cisplatin-based regimens were included. Medical records of the patients noted that lobaplatin (30 mg/m2) or cisplatin (25 mg/m2), combined with another chemotherapeutic agent such as Gemcitabine (1000 mg/m2) or Vinorelbine (25 mg/m2), was intravenously given to the patients on a basis of twenty-one days as one treatment cycle. All the patients were followed until August 2017. The endpoint of this study was progression-free survival (PFS), overall survival (OS), and estimated objective response rate (RR). Safety and drug tolerability data were also obtained. Lobaplatin-based regimens prolonged PFS compared to cisplatin-based regimens (median 13.2 vs 4.7 months, hazard ratio = 0.37, 95% confidence intervals: 0.21-0.67, P = .0007), while OS was not significantly different between the two groups (hazard ratio = 0.72, 95% confidence intervals: 0.40-1.30, P = .2767), as was objective RR (37.8% vs 33.4%, x 2 = 0.19, P = .6653). Nausea/vomiting and renal injury were more frequent with cisplatin-based regimens. Our results show that lobaplatin-based regimens are superior to cisplatin in terms of efficacy and are better tolerated.