Transporter-Mediated Interaction Between Platinum Drugs and Sorafenib at the Cellular Level

Combination of ethyl acetate fraction from Calotropis gigantea stem bark and sorafenib induces apoptosis in HepG2 cells

The cytotoxicity of the ethyl acetate fraction of the Calotropis gigantea (L.) Dryand. (C. gigantea) stem bark extract (CGEtOAc) has been demonstrated in many types of cancers. This study examined the improved cancer therapeutic activity of sorafenib when combined with CGEtOAc in HepG2 cells. The cell viability and cell migration assays were applied in HepG2 cells treated with varying concentrations of CGEtOAc, sorafenib, and their combination. Flow cytometry was used to determine apoptosis, which corresponded with a decline in mitochondrial membrane potential and activation of DNA fragmentation. Reactive oxygen species (ROS) levels were assessed in combination with the expression of the phosphatidylinositol-3-kinase (PI3K)/ protein kinase B (Akt)/ mammalian target of rapamycin (mTOR) pathway, which was suggested for association with ROS-induced apoptosis. Combining CGEtOAc at 400 μg/mL with sorafenib at 4 μM, which were their respective half-IC50 concentrations, significantly inhibited HepG2 viability upon 24 h of exposure in comparison with the vehicle and each single treatment. Consequently, CGEtOAc when combined with sorafenib significantly diminished HepG2 migration and induced apoptosis through a mitochondrial-correlation mechanism. ROS production was speculated to be the primary mechanism of stimulating apoptosis in HepG2 cells after exposure to a combination of CGEtOAc and sorafenib, in association with PI3K/Akt/mTOR pathway suppression. Our results present valuable knowledge to support the development of anticancer regimens derived from the CGEtOAc with the chemotherapeutic agent sorafenib, both of which were administered at half-IC50, which may minimize the toxic implications of cancer treatments while improving the therapeutic effectiveness toward future medical applications.

The copper transporter CTR1 and cisplatin accumulation at the single-cell level by LA-ICP-TOFMS

More than a decade ago, studies on cellular cisplatin accumulation via active membrane transport established the role of the high affinity copper uptake protein 1 (CTR1) as a main uptake route besides passive diffusion. In this work, CTR1 expression, cisplatin accumulation and intracellular copper concentration was assessed for single cells revisiting the case of CTR1 in the context of acquired cisplatin resistance. The single-cell workflow designed for in vitro experiments enabled quantitative imaging at resolutions down to 1 µm by laser ablation-inductively coupled plasma-time-of-flight mass spectrometry (LA-ICP-TOFMS). Cisplatin-sensitive ovarian carcinoma cells A2780 as compared to the cisplatin-resistant subline A2780cis were investigated. Intracellular cisplatin and copper levels were absolutely quantified for thousands of individual cells, while for CTR1, relative differences of total CTR1 versus plasma membrane-bound CTR1 were determined. A markedly decreased intracellular cisplatin concentration accompanied by reduced copper concentrations was observed for single A2780cis cells, along with a distinctly reduced (total) CTR1 level as compared to the parental cell model. Interestingly, a significantly different proportion of plasma membrane-bound versus total CTR1 in untreated A2780 as compared to A2780cis cells was observed. This proportion changed in both models upon cisplatin exposure. Statistical analysis revealed a significant correlation between total and plasma membrane-bound CTR1 expression and cisplatin accumulation at the single-cell level in both A2780 and A2780cis cells. Thus, our study recapitulates the crosstalk of copper homeostasis and cisplatin uptake, and also indicates a complex interplay between subcellular CTR1 localization and cellular cisplatin accumulation as a driver for acquired resistance development.

Hepatic Arterial Infusion Chemotherapy of Oxaliplatin, Fluorouracil, and Leucovorin With or Without Sorafenib as Initial Treatment for Advanced Hepatocellular Carcinoma

Purpose

Our previous study showed that hepatic arterial infusion chemotherapy (HAIC) using oxaliplatin, fluorouracil, and leucovorin (FOLFOX) plus sorafenib provided a significant survival benefit over sorafenib for advanced hepatocellular carcinoma. However, it is unclear whether the survival benefit should be attributed to the synergism between HAIC and sorafenib or just HAIC alone. We aim to compare HAIC using FOLFOX plus sorafenib with HAIC alone in patients with advanced hepatocellular carcinoma.

Materials and Methods

This was a retrospective study including 225 eligible patients treated with HAIC using FOLFOX (HAIC alone group, n=126, oxaliplatin 85 mg/m², leucovorin 400 mg/m², fluorouracil bolus 400 mg/m² and 2400 mg/m² for 46 hours, every 3 weeks) alone or HAIC plus sorafenib (soraHAIC group, n=99, sorafenib 400 mg twice daily). Survival curves were calculated by the Kaplan-Meier method, and propensity-score matching was used to reduce bias.

Results

The soraHAIC group showed a longer overall survival (12.9 [95% CI, 10.4-15.4] vs. 10.5 [95% CI, 9.5-11.5] months, HR=0.71 [95% CI, 0.53-0.96]; P=0.025), a better progression free survival (7.0 [95% CI, 5.3-8.8] vs. 5.3 [95% CI, 3.5-7.1] months, HR=0.76 [95% CI, 0.58-0.99]; P=0.046), and a higher disease control rate (RECIST 1.1: 74.8% vs. 61.1%, P=0.030) than the HAIC alone group. In multivariate analysis, soraHAIC was an independent favor factor for survival. In terms of the grade 3/4 adverse event, hand–foot skin reaction was more frequent in the soraHAIC group than the HAIC alone group. In the propensity-score matched cohorts (93 pairs), the overall survival, the progression free survival and disease control rates in the soraHAIC group were also better than those in the HAIC group (P<0.05).

Conclusion

HAIC plus sorafenib may improve overall survival and progression free survival compared with HAIC alone as initial treatment for advanced hepatocellular carcinoma.

Efficacy of sequential sorafenib plus hepatic arterial infusion chemotherapy in patients with Barcelona Clinic Liver Cancer stage B and C hepatocellular carcinoma: a retrospective single-institution study

AIM OF THE STUDY

To evaluate the efficacy of sequential combination therapy using sorafenib and hepatic arterial infusion chemotherapy (HAIC) in patients with Barcelona Clinic Liver Cancer stage B/C hepatocellular carcinoma (HCC).

MATERIAL AND METHODS

We recruited 98 BCLC stage B/C HCC patients at our institute, who received either sorafenib monotherapy or planned sequential sorafenib-HAIC combination therapy. A total of 26 patients (combination group) received sorafenib for one or two months, followed by HAIC with a single dose of cisplatin-lipiodol suspension and a continuous infusion of 5-fluorouracil. Sorafenib-HAIC cycles were repeated every 2-3 months. The remaining 72 patients (control group) were treated with sorafenib alone. Clinical characteristics and treatment outcomes were compared between the groups. Inverse probability weighting (IPW) using propensity scores was applied to adjust for the between-group differences in baseline characteristics.

RESULTS

The combination group had a significantly lower frequency of extrahepatic metastasis and BCLC stage C disease compared with the control group but had more intrahepatic lesions. The crude median overall survival (OS) was 17.1 months in the combination group compared with 9.7 months in the control group (p = 0.01). The objective response rate was 23.1% in the combination group vs. 6.9% in the control group (p = 0.06). Multivariate analysis identified receipt of sorafenib-HAIC combination (HR: 0.521, 95% CI: 0.297-0.915, p = 0.02) and α-fetoprotein (≥ 400 ng/ml) at baseline as independent factors associated with OS. After adjustment with IPW the combination group still had significantly better OS than the control group (p = 0.04).

CONCLUSIONS

The sequential sorafenib-HAIC combination can be an effective and promising treatment option for selected patients with BCLC stage B/C HCC.