Effects of arsenic trioxide on radiofrequency ablation of VX2 liver tumor: intraarterial versus intravenous administration

Feasibility of rabbit auricular VX2 tumor model as an experimental model for intra-arterial embolization

This study aimed to evaluate the feasibility of VX2 tumor in rabbit auricles as an experimental model for intra-arterial embolization. This study was approved by our Institutional Animal Care and Use Committee. VX2 tumors were implanted in both auricles of 12 New Zealand White Rabbits. To investigate the angiographic and pathologic characteristics, angiography, ultrasonography, and thermography were performed 1-2 weeks after inoculation, and image analysis was performed. The animals were sacrificed thereafter, and histologic analysis was conducted by a pathologist. Tumors did not grow in 3/24 auricles of 12 rabbits used in the experiment, and one rabbit died during anesthesia for an ultrasonographic examination. Therefore, images were obtained from a total of 19 auricles. Angiography was successfully performed in 11 rabbits, and hypervascularity and tumor feeding vessels were clearly observed in all tumors. The enhancement effect increased significantly as the volume increased. In histologic evaluation, the average area of necrosis was 27%. In conclusion, a rabbit auricular VX2 tumor model is easy to create, and its features can be conveniently observed on visual inspection. Moreover, it appears hypervascular on angiography, and the tumor feeding vessel is easy to approach. Thus, it is useful for studying intra-arterial embolization.

Arsenic trioxide inhibits angiogenesis of hepatocellular carcinoma after insufficient radiofrequency ablation via blocking paracrine angiopoietin-1 and angiopoietin-2

OBJECTIVES

Angiogenesis occurs during tumor progression of hepatocellular carcinoma (HCC) after insufficient radiofrequency ablation (RFA). Arsenic trioxide (ATO) shows promising therapeutic potential in advanced HCC. Whether ATO regulates angiogenesis and can be used to prevent tumor progression in HCC after insufficient RFA is still unknown.

METHODS

Insufficient RFA was simulated using a water bath. MTT assay and tube formation assay were used to evaluate the effects of ATO on viability and proangiogenic abilities of SMMC7721 and HepG2 cells after insufficient RFA in vitro. The molecular changes with the treatment of ATO were evaluated through Western blot. An ectopic nude mice model was used to evaluate the effect of ATO on the tumor of SMMC7721 cells in vivo after insufficient RFA.

RESULTS

In this study, HepG2 and SMMC7721 cells after insufficient RFA (named HepG2-H and SMMC7721-H, respectively) showed higher proliferation than the untreated cells and promoted tube formation of endothelial cells in a paracrine manner. ATO eliminated the difference in proliferation between untreated and RFA-treated cells and suppressed angiogenesis induced by HCC cells after insufficient RFA through the Ang-1 (angiopoietin-1)/Ang-2 (angiopoietin-2)/Tie2 pathway. Hif-1α overexpression abolished the inhibitory effect of ATO on angiogenesis in HCC after insufficient RFA. ATO inhibited tumor growth and angiogenesis in HCC after insufficient RFA.

CONCLUSIONS

Our results demonstrate that ATO blocks the paracrine signaling of Ang-1 and Ang-2 by inhibiting p-Akt/Hif-1α and further suppresses the angiogenesis of HCC after insufficient RFA.

MiRNA-148a inhibits cell growth and drug resistance by regulating WNT10a expression in renal cell carcinoma

Background

We aimed to explore miR-148a exerts a tumor suppressor effect and arsenic trioxide (As₂O₃) sensitivity on renal cell carcinoma (RCC).

Methods

We performed polymerase chain reaction (PCR) on 42 pairs of tumor and paracancerous samples collected from RCC patients to investigate the miR-148a expression; meanwhile, we analyzed the interplay between clinical indicators and miR-148a expression of RCC. Then, the influence of miR-148a overexpression on the functions of RCC cells were analyze using transwell migration assay, Cell Counting Kit-8 (CCK-8), and cell wound healing assay. Furthermore, the ability of miR-148a to sensitize Caki-1 cells treated with As₂O₃ were detected using flow cytometry. Finally, the relevant mechanism of miR-148a on the downstream gene Wnt family member 10A (WNT10a) was explored by cell reverse method.

Results

The results from RCC patients indicated a significantly lower miR-148a level than adjacent tissues. The low miR-148a expression increased prevalence of distant metastasis and decreased survival rate compared to those with high expression in patients. In the RCC cell lines, the proliferation and metastasis ability of the miR-148a mimic group was remarkably lower than the miR-NC group. At the same time, it was verified that WNT10a was remarkably higher cell lines and RCC tissues; and negatively related to miR-148a expression. In addition, miR-148a mimics were found to remarkably reduce the protein expression of WNT10a. In the cell reverse experiment, overexpression of WNT10a was confirmed to offset the miR-148a mimics effect on metastasis and proliferation of RCC cells. In addition, an increase in relative apoptosis was detected in As₂O₃ treated with/without miR-148a mimics for 48 hours, and apoptosis was significantly reduced after transfection with WNT10a in the Caki-1 cell line and significantly reduced after combined treatment.

Conclusions

The study revealed that miR-148a is associated with distant metastases and leads to poor prognosis in RCC patients. Moreover, miR-148a inhibit the malignant progression and increase the sensitivity of RCC cells to As₂O₃ by regulating WNT10a.

Improved Outcomes with Induction Chemotherapy Combined with Arsenic Trioxide in Stage 4 Neuroblastoma: A Case Series

Objective: The apoptotic and cytotoxic effects of arsenic trioxide (ATO) makes it a potentially suitable agent for the treatment of patients with neuroblastoma with poor prognosis; therefore, we try to evaluate the effectiveness and safety of ATO combined with reinduction/induction chemotherapy in children with recurrent/refractory or newly diagnosed stage 4 neuroblastoma. Methods: Retrospective analysis was performed on seven pediatric patients with recurrent /refractory or newly diagnosed stage 4 neuroblastoma treated with traditional reinduction/induction chemotherapy combined with ATO. Results: A total of 7 patients were treated synchronously with ATO and chemotherapy for up to nine courses; all patients received conventional chemotherapy plus a 0.16 mg/kg/day dose of intravenous ATO during reinduction/induction chemotherapy. Treatment was effective in five patients and ineffective in the other two patients. The overall response rate was 71.43% (5 of 7). The side effects of the ATO combination were minor, whereby only treatment in one patient was terminated at the sixth course due to a prolonged QT interval (0.51 s), which returned to normal after symptomatic treatment. Conclusions: ATO can be safely and effectively combined with chemotherapy drugs as a potential alternative means of treatment for high-risk stage 4 neuroblastoma, and we have observed that ATO can restore the sensitivity of chemotherapy in some patients who were resistant to previous chemotherapy. Further investigations and clinical data are required to confirm these observations.

Periostin involved in the activated hepatic stellate cells-induced progression of residual hepatocellular carcinoma after sublethal heat treatment: its role and potential for therapeutic inhibition

BACKGROUND

Incomplete thermal ablation may induce invasiveness of hepatocellular carcinoma (HCC). Here, we investigated whether activated hepatic stellate cells (HSCs) would accelerate the progression of residual HCC after sublethal heat treatment, and thus sought to identify the potential targets.

METHODS

Hepatocellular carcinoma cells were exposed to sublethal heat treatment and then cultured with the conditioned medium from activated HSCs (HSC-CM). The cell proliferation, migration, invasion and parameters of epithelial-mesenchymal transition (EMT) were analyzed. In vivo tumor progression of heat-treated residual HCC cells inoculated with activated HSCs was studied in nude mice.

RESULTS

HSC-CM significantly enhanced the proliferation, motility, invasion, prominent EMT activation and decreased apoptosis of heat-exposed residual HCC cells. These increased malignant phenotypes were markedly attenuated by neutralizing periostin (POSTN) in HSC-CM. Furthermore, exogenous POSTN administration exerted the similar effects of HSC-CM on heat-treated residual HCC cells. POSTN induced the prominent activation of p52Shc and ERK1/2 via integrin β1 in heat-exposed residual HCC cells. Vitamin D analog calcipotriol blocked POSTN secretion from activated HSCs. Calcipotriol plus cisplatin significantly suppressed the activated HSCs-enhanced tumor progression of heat-treated residual HCC cells via the inhibited POSTN expression and the increased apoptosis.

CONCLUSIONS

Activated HSCs promote the tumor progression of heat-treated residual HCC through the release of POSTN, which could be inhibited by calcipotriol. Calcipotriol plus cisplatin could be used to thwart the accelerated progression of residual HCC after suboptimal heat treatment.

Ultrasound-guided radiofrequency ablation enhances natural killer-mediated antitumor immunity against liver cancer

For patients with liver cancer who are not sufficiently fit for surgical resection, radiofrequency ablation (RFA) is an effective and low risk treatment modality; however, the mechanism underlying this procedure is not fully understood. In the present study, a series of experiments were conducted, which demonstrated that RFA therapy stimulates innate antitumor immunity via directly enhancing natural killer (NK) cell cytotoxicity, thus achieving a favorable outcome for patients with liver tumors. It was determined that the percentage of NK cells within the peripheral blood of the rabbits in the RFA treatment groups were significantly higher, compared with the control groups. The levels of interferon-γ and tumor necrosis factor-α in NK cells were also significantly upregulated following thermal coagulation induced via RFA. In addition, RFA enhanced the NK cell receptor, NK group 2D (NKG2D), expression and NK cell antitumor cytotoxicity in hepatic cancer cells. The results indicated that the RFA treatment could effectively eliminate liver tumors via enhancing NK-mediated antitumor activity and NKG2D expression.

Perfused hypertonic-saline-augmented needle enlarges ablation zones in ex vivo porcine livers

There is a great clinical requirement to improve radiofrequency ablation (RFA) efficacy and create larger coagulation necrotic areas. The aim of the present study was to assess the ability of a hypertonic-saline (HS)-enhanced multipolar RFA technique using a perfused electrode to increase RF-created coagulation necrosis, and to compare that technique with natural saline-augmented needle and conventional multipolar RFA. A total of 18 ablations were performed in explanted porcine livers. A total of 6 thermal ablation zones were created in each of 3 groups treated with the conventional multipolar mode, the multipolar mode with 0.9% NaCl and the multipolar mode with 6% NaCl, respectively. During RFA, the dimensions and volumes of the ablation zones were compared, and gross and microscopic pathological evaluations were performed. Multipolar RFA with 6% NaCl created the largest short-axis diameters and volumes of coagulation necrosis (3.89±0.09 mm and 40.01±2.86 mm³, respectively) among the three groups (conventional group: 2.31±0.04 mm and 8.99±0.52 mm³, respectively; 0.9% NaCl solution group: 3.17±0.05 mm and 21.79±1.05 mm³, respectively). Overall, multipolar RFA with the instillation of 6% NaCl solution through an open perfusion system created a larger ablation zone compared with the conventional and 0.9% NaCl modes. Therefore, HS-enhanced multipolar RFA may be a promising approach for treating large liver tumors.

Enhanced efficacy of radiofrequency ablation for hepatocellular carcinoma using a novel vascular disrupting agent, CKD-516

BACKGROUND

CKD-516 is a novel vascular disrupting agent that shuts down intratumoral blood flow. We therefore hypothesized that concomitant administration of CKD-516 would enhance the therapeutic efficacy of radiofrequency ablation (RFA) by reducing heat sink effects. We assessed the effects of the combination of CKD-516 and RFA in a rat orthotopic hepatocellular carcinoma (HCC) model.

METHODS

Rat HCC cells (N1-S1) were engrafted into the hepatic lobe of Sprague-Dawley (SD) rats. Mice were randomly divided into two groups: RFA-only and CKD-RFA. In the CKD-RFA group, CKD-516 was administered by intraperitoneal injection 2 h before RFA. Ablation zone size was measured on triphenyltetrazolium chloride-stained specimens. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was performed to evaluate the area of apoptosis/necrosis in the ablation zone. Immunohistochemistry with anti-CD31 antibody was performed to evaluate the effect of CKD-516 on tumor vessels.

RESULTS

Ablation zone size was significantly larger in the CKD-RFA group than in the RFA-only group (243.10 ± 74.39 versus 123.30 ± 28.17 mm², p < 0.001). On TUNEL staining, the area of apoptosis/necrosis was also significantly larger in the CKD-RFA group than in the RFA-only group (274.44 ± 140.78 versus 143.74 ± 90.13 mm²; p = 0.006). Immunohistochemistry with anti-CD31 antibody revealed patent tumor vessels in the RFA-only group, while collapsed vessels were seen in the CKD-RFA group, indicating a vascular shutdown effect of CKD-516.

CONCLUSION

Concomitant administration of CKD-516 during RFA can increase the ablation zone of tumors due to its vascular disrupting effect.

Randomized clinical control study of locoregional therapy combined with arsenic trioxide for the treatment of hepatocellular carcinoma

BACKGROUND

The objective of this study was to determine the efficacy and safety of locoregional therapy (LRT) combined with arsenic trioxide (As2 O3 ) treatment in primary hepatocellular carcinoma (HCC) patients.

METHODS

One hundred twenty-five primary HCC patients were recruited for a randomized controlled study. Patients were randomly divided into group A (n = 61) and group B (n = 64). All patients received transarterial chemoembolization. Group A patients were given As2 O3 at 10 mg/d for 4 courses (21 days per course) with a 2-week interval between courses. Survival times, therapeutic responses, extrahepatic metastases, and adverse events were recorded.

RESULTS

A better therapeutic response was found in group A patients, as shown by higher objective response rate (ORR) and clinical benefit rate (CBR) values in group A versus group B (ORR, 81.96% [95% confidence interval (CI), 72.32%-91.62%] vs 59.37% [95% CI, 47.34%-71.41%], χ(2)  = 7.650, P < .05; CBR, 95.08% [95% CI, 89.66%-100.00%] vs 81.25% [95% CI, 71.69%-90.81%], χ(2)  = 5.659, P < .05). There were fewer patients with extrahepatic metastases in group A versus group B (group A, 6 cases or 9.84% [95% CI, 2.36%-17.31%]; group B, 12 cases or 18.75% [95% CI, 9.19%-28.31%]). The survival rate for group A patients was significantly higher than that for group B patients (P < .05). No significant differences were found between the 2 groups in terms of hematology or digestive system, liver, or kidney dysfunction except for facial and limb edema.

CONCLUSIONS

LRT combined with As2 O3 treatment prevents extrahepatic metastasis and prolongs the survival time for primary HCC patients.

Dual switching monopolar radiofrequency ablation using a separable clustered electrode: comparison with consecutive and switching monopolar modes in ex vivo bovine livers

Objective

To compare the in-vitro efficiency of dual-switching monopolar (DSM) radiofrequency ablation (RFA) using a separable clustered electrode (Octopus® electrodes) with consecutive monopolar (CM) and switching monopolar (SM) RFA techniques to create an ablative zone in the explanted bovine liver.

Materials and Methods

For DSM-RFA, we used a prototype, three-channel, dual generator RFA Unit and Octopus® electrodes with three, 17 gauge internally cooled electrodes. The RFA Unit allowed simultaneous radiofrequency (RF) energy delivery to two electrodes of the Octopus® electrodes as well as automatic switching among the three electrode pairs according to the impedance changes. RF energy was sequentially applied to one of the three electrodes for 24 minutes (group A; CM mode, n = 10) or alternatively applied for 12 minutes (group B; SM mode, n = 10) or concurrently applied to a pair of electrodes for 12 minutes (group C; DSM mode, n = 10) in explanted bovine livers. Changes in the impedance and current during RFA as well as the dimensions of the thermal ablative zones were compared among the three groups.

Results

The mean, delivered RF energy amounts in groups A, B, and C were 63.15 ± 8.6 kJ, 72.13 ± 5.4 kJ, and 106.08 ± 13.4 kJ, respectively (p < 0.001). The DSM mode created a significantly larger ablation volume than did the other modes, i.e., 68.1 ± 10.2 cm³ (group A), 92.0 ± 19.9 cm³ (group B), and 115.1 ± 14.0 cm³ (group C) (p < 0.001). The circularity in groups A, B, and C were 0.84 ± 0.06, 0.87 ± 0.04 and 0.90 ± 0.03, respectively (p = 0.03).

Conclusion

DSM-RFA using Octopus® electrodes can help create large ablative zones within a relatively short time.

Evaluation of the in vivo efficiency and safety of hepatic radiofrequency ablation using a 15-G Octopus® in pig liver

OBJECTIVE

To determine in vivo efficacy of radiofrequency ablation (RFA) in porcine liver by using 15-gauge Octopus® (15-G Octopus®) electrodes to create a large coagulation.

MATERIALS AND METHODS

A total of 18 coagulations were created by using a 180-W generator and 15-G Octopus® electrodes during laparotomy, performed in 14 pigs. Coagulation necrosis was created in the pig livers by the use of one of three RFA protocols: 1) group A, monopolar RFA using a 15-G Octopus® electrode with a 5-mm inter-electrode distance (n = 4); 2) group B, monopolar RFA using a 15-G Octopus® electrode with a 10-mm inter-electrode distance (n = 6); and 3) group C, switching monopolar RFA using two 15-G Octopus® electrodes (n = 8). The energy efficiency, shape, maximum and minimum diameters (Dmx and Dmi), and the volume of the coagulation volume were measured in each group. The Summary statistics were obtained and Mann-Whitney test was were performed.

RESULTS

The mean ablated volume of each group was 49.23 cm(3) in A, 64.11 cm(3) in B, and 72.35 cm(3) in C. The mean Dmx and Dmi values were 5.68 cm and 4.58 cm in A and 5.97 cm and 4.97 cm in B, respectively. In group C, the mean diameters of Dmx and Dmi were 6.80 cm and 5.11 cm, respectively. The mean ratios of Dmi/Dmx were 1.25, 1.20, and 1.35 in groups A, B, and C, respectively. There was one animal death during the RFA procedure, the cause of which could not be subsequently determined. However, there were no other significant, procedure-related complications during the seven-hour-delayed CT scans.

CONCLUSION

RFA procedures using 15-G Octopus® electrodes are useful and safe for creating a large ablation in a single electrode model as well as in the multiple electrodes model.