Thermal Ablation Induces Transitory Metastatic Growth by Means of the STAT3/c-Met Molecular Pathway in an Intrahepatic Colorectal Cancer Mouse Model

A Bioligical Perspective on the role of miR-206 in Colorectal cancer

MicroRNAs (miRs) have emerged as pivotal regulators in the development and progression of colorectal cancer (CRC), and MicroRNA-206 (miR-206) has garnered attention as a potentially influential factor. However, the specific biological functions and complete mechanistic understanding of miR-206 in CRC remain largely uncharacterized. This study aims to bridge this research gap by providing a comprehensive analysis of miR-206's role in CRC. An exploration of the molecular mechanisms regulated by miR-206, its intricate interplay with target genes, and its significant impact on cellular processes highlights its potential utility as both a diagnostic marker and a therapeutic target. The significance of this research lies in potentially enabling the development of innovative therapeutic approaches, ultimately aiming to improve prognosis and survival rates in CRC patients by elucidating the functions of miR-206. Critical pathways, such as c-Met and PTEN/AKT, play crucial roles within the regulatory network of miR-206 in CRC and impact various cellular processes involved in CRC pathogenesis, metastasis, and treatment response. Understanding the complex interactions between miR-206 and key signaling pathways like c-Met and PTEN/AKT is crucial for understanding the underlying mechanisms driving CRC initiation and progression. This knowledge can inform the development of targeted therapeutic interventions, potentially leading to improved patient outcomes and advances in CRC management.

The Impact of Microwave Ablation on Recurrence and Metastasis of Hepatocellular Carcinoma: Insights From Animal Studies and Cytokine Profiling

Background

Microwave ablation (MWA) is commonly used to treat hepatocellular carcinoma (HCC), but its effects on normal liver tissue and tumors remain unclear. While MWA causes direct tumor destruction, it also induces inflammatory responses in the surrounding liver tissue, which may influence tumor progression, metastasis, and recurrence. The role of cytokine alterations in this post-ablation inflammatory microenvironment is crucial for understanding how MWA impacts tumor behavior.

Purpose

This study aims to investigate the impact of post-ablation inflammatory responses on HCC recurrence and metastasis through animal experiments and cytokine profiling, with the goal of identifying potential biomarkers or therapeutic targets.

Materials and Methods

This study involved 35 male C57BL/6 mice (6-8 weeks old) to establish metastatic and orthotopic cancer models. The effects of normal liver tissue ablation and HCC ablation on tumor metastasis and recurrence were investigated. Cytokine expression changes were assessed using the Proteome Profiler Mouse XL Cytokine Array, and prognostic implications were analyzed using the TCGA database. Multiple group comparisons assessed using the Mann-Whitney U-test. Statistical significance was defined as a two-tailed p-value less than 0.05.

Results

Microwave ablation of normal liver tissue promotes intrahepatic metastasis of HCC. Incomplete ablation of liver tumors accelerates intrahepatic or pulmonary metastasis. Post-ablation, increased expression of MMP-9, OPN, VEGF, CHI3L1, AREG, CXCL2, and IL-1α in the peritumoral region suggests a shift toward a pro-inflammatory and pro-metastatic microenvironment, potentially facilitating tumor cell invasion, angiogenesis, and immune evasion.

Conclusion

HCC recurrence and metastasis following ablation may be driven by cytokine-mediated changes in the tumor microenvironment. Targeting key cytokines such as MMP-9, OPN, and CHI3L1 could provide new strategies for improving post-ablation outcomes and reducing recurrence rates in clinical settings.

Prognostic Comparison of Complete vs. Incomplete Radiofrequency Ablation for Colorectal Liver Metastases: A Multicenter Prospective Study

BACKGROUND

Radiofrequency ablation (RFA) is a curative treatment for colorectal liver metastases (CLMs) in selected patients. NCCN guidelines recommend RFA for both unresectable and select resectable CLMs when complete ablation with adequate margins is feasible. While RFA can achieve oncologic outcomes comparable to surgery in well-selected patients, residual tumors are associated with a poorer prognosis.

OBJECTIVES

To identify predictors of residual tumor after percutaneous RFA for CLMs and evaluate their impact on overall survival (OS) and new intrahepatic metastases (NIHM).

METHODS

We prospectively included patients with CLMs who underwent percutaneous RFA from November 2019 to November 2022. Dynamic contrast-enhanced computed tomography assessed CLMs before and after RFA. Residual tumor was defined as active tumor visible immediately post-ablation or within 4-8 weeks, within 1 cm of the ablation zone. Data from three centers formed a developmental cohort, validated with patients from a fourth center. Cox regression and Kaplan-Meier analysis assessed local tumor progression-free survival (LTPFS), NIHM, and OS.

RESULTS

Among 200 patients (mean age 61 years, 126 men) with 410 tumors, independent predictors of residual tumors included perivascular tumor location (odds ratio [OR] = 6.673), tumor size ≥ 20 mm (OR = 3.925), and minimal ablative margin (OR = 0.599). These factors also predicted LTPFS. NIHM was more frequent in the residual tumor group than in the complete RFA (cRFA) group (p = 0.002). Median OS was 45 months, shorter in the residual tumor group (30 vs. 48 months, p = 0.009). Patients with NIHM who received transarterial chemoembolization combined with hepatic arterial infusion chemotherapy had a median OS of 43 months, compared to 34 months with RFA alone (p = 0.039).

CONCLUSIONS

A non-perivascular tumor location, tumor size < 20 mm, and a sufficient ablation margin are essential for achieving complete RFA. Residual tumors are associated with increased NIHM and shorter OS.

Radiofrequency ablation: mechanisms and clinical applications

Radiofrequency ablation (RFA), a form of thermal ablation, employs localized heat to induce protein denaturation in tissue cells, resulting in cell death. It has emerged as a viable treatment option for patients who are ineligible for surgery in various diseases, particularly liver cancer and other tumor-related conditions. In addition to directly eliminating tumor cells, RFA also induces alterations in the infiltrating cells within the tumor microenvironment (TME), which can significantly impact treatment outcomes. Moreover, incomplete RFA (iRFA) may lead to tumor recurrence and metastasis. The current challenge is to enhance the efficacy of RFA by elucidating its underlying mechanisms. This review discusses the clinical applications of RFA in treating various diseases and the mechanisms that contribute to the survival and invasion of tumor cells following iRFA, including the roles of heat shock proteins, hypoxia, and autophagy. Additionally, we analyze‌ the changes occurring in infiltrating cells within the TME after iRFA. Finally, we provide a comprehensive summary of clinical trials involving RFA in conjunction with other treatment modalities in the field of cancer therapy, aiming to offer novel insights and references for improving the effectiveness of RFA.

Radiofrequency-responsive black phosphorus nanogel crosslinked with cisplatin for precise synergy in multi-modal tumor therapies

Radiofrequency-responsive nanoparticles (RFNPs) have drawn increasingly attentions as RF energy absorbing antenna to enhance antitumor efficacy of radiofrequency ablation (RFA). However, it remains a huge challenge for inorganic RFNPs to precisely synergize RFA with other antitumor modes in a clinically acceptable way on bio-safety and bio-compatibility. In this work, RF-responsive black phosphorus (BP) nanogel (BP-Pt@PNA) was successfully fabricated by crosslinking coordination of cisplatin with BP and temperature sensitive polymer PNA. BP-Pt@PNA exhibited strong RF-heating effect and RF-induced pulsatile release of cisplatin. Under RF irradiation, BP-Pt@PNA exhibited cytotoxic enhancement on 4T1 cells. By the synergistic effect of BP and cisplatin, BP-Pt@PNA achieved RF-stimulated systemic immune effect, thus induced enhance suppression on tumor growth and metastasis. Moreover, BP-Pt@PNA realized long-term drug retention in tumor and favorable embolization to tumor-feeding arteries. With high drug loading capacity and favorable bio-safety and bio-degradability, BP-Pt@PNA is expected as an ideal RFNP for precisely synergizing RFA with other antitumor modes in clinical application.

CT-guided high dose rate brachytherapy can induce multiple systemic proteins of proliferation and angiogenesis predicting outcome in HCC

BACKGROUND AND PURPOSE

To determine the potential prognostic value of proliferation and angiogenesis plasma proteins following CT-guided high dose rate brachytherapy (HDR-BT) of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

For this prospective study, HDR-BT (1 × 15 Gy) was administered to 24 HCC patients. Plasma was obtained and analyzed using an Olink proteomics Target-96 immuno-oncology-panel that included multiple markers of angiogenesis and proliferation. Fold-change (FC) ratios were calculated by comparing baseline and 48 h post HDR-BT paired samples. Patients were classified as responders (n = 12) if they had no local progression within 6 months or systemic progression within 2 years. Non-responders (n = 12) had recurrence within 6 months and/or tumor progression or extrahepatic disease within 2 years.

RESULTS

Proliferation marker EGF was significantly elevated in non-responders compared to responders (p = 0.0410) while FGF-2, HGF, and PlGF showed no significant differences. Angiogenesis markers Angiopoietin-1 and PDGF-B were likewise significantly elevated in non-responders compared to responders (p = 0.0171, p = 0.0462, respectively) while Angiopoietin-2, VEGF-A, and VEGFR-2 did not differ significantly. Kaplan-Meier analyses demonstrated significantly shorter time to systemic progression in patients with increased EGF and Angiopoietin-1 (p = 0.0185, both), but not in patients with one of the remaining proteins elevated (all p > 0.1). Pooled analysis for these 9 proteins showed significantly shorter time to systemic progression for FC ≥1.3 and ≥1.5 for at least 3 proteins elevated (p = 0.0415, p = 0.0193, respectively).

CONCLUSION

Increased plasma levels of EGF and Angiopoietin-1 after HDR-BT for HCC are associated with poor response and may therefore function as predictive biomarkers of outcome.

Differential cytokine and chemokine expression after ablation vs. resection in colorectal cancer liver metastasis

Background

Surgical resection remains the main curative treatment for colorectal liver metastases (CRLM). Radiofrequency ablation (RFA) is increasingly employed for small, deep lying or otherwise inoperable lesions. However, RFA can induce pro-tumorigenic effects on residual tumor cells, hereby possibly promoting tumor recurrence. Contrastingly, post-RFA tumor debris as an antigen source can also generate anti-cancer immune responses. Utilizing this, current studies on combining RFA with immune therapy appear promising. Here, in an attempt to shed light on this controversy, cytokines involved in inflammation, (lymph)angiogenesis, immune cell recruitment and tumor cell invasion were investigated post-RFA versus post-resection in CRLM patients.

Methods

Cytokine and chemokine serum levels pre-operation, 4 h and 24 h post-operation were analyzed in CRLM patients undergoing RFA (n = 8) or partial hepatectomy (n = 9) using Multiplex immunoassays. Statistical analyses were performed between as well as within individual intervention groups.

Results

Post-RFA, significantly increased levels of acute phase proteins SAA1 and S100A8, IL-6, IL-1Ra, MIP3b (CCL19) and MMP9 were observed along with decreases in Fibronectin, MCP-1 (CCL2), and Tie-2. Post-resection, increased levels of PDGFbb, I309 (CCL1), Apelin, MIF, IL-1b and TNFα were seen. All p-values <0.05.

Conclusion

Pro-inflammatory responses mediated by different cytokines were seen after both RFA and resection, possibly influencing residual tumor cells and tumor recurrence. As both ablation and resection trigger inflammation and immune cell recruitment (albeit via distinct mechanisms), these data suggest that further research may explore combining immune therapy with not only RFA but also resection.

Key message

Analysis of patients' serum after radiofrequency ablation versus resection of colorectal liver metastases (CRLM) showed that these interventions trigger inflammation and immune cell recruitment, via different cyto- and chemokine pathways. This suggests a possible future strategy of combining immune therapy with not only ablative techniques but also with resection of CRLM.

Clinical outcomes and tumor microenvironment response to radiofrequency ablation therapy: a systematic review and meta-analysis

Background

Radiofrequency ablation (RFA) utilizes minimally invasive high-energy current to precisely ablate tumor cells. It has been utilized in many cancer types including thyroid, lung, and liver cancer. It has been shown to provide adequate ablative margins with minimal complications; however, incomplete RFA may lead to recurrence of tumor. The underlying cellular mechanism and behavior of ablated cancer tissue is poorly understood.

Methods

A systematic review was performed, searching EMBASE, Web of Science, PubMed, and Scopus for studies published up to March 2022 and reported following PRISMA guidelines. Collection was performed by two groups of investigators to avoid risk of bias. The Cochrane Collaboration's tool was used for assessing risk of bias. We identified human, in vivo, and in vitro research studies utilizing RFA for tumor tissues. We required that the studies included at least one of the following: complications, recurrence, or survival, and took interest to studies identifying cellular signaling pathway patterns after RFA. Descriptive statistical analysis was performed in 'R' software including mean and confidence interval.

Results

The most frequent cancers studied were liver and lung cancers accounting for 57.4% (N=995) and 15.4% (N=267), followed by esophageal (N=190) and breast cancer (N=134). The most common reported complications were bleeding (19%) and post-operative pain (14%). In our literature search, four independent studies showed upregulation and activation of the VEGF pathway following RFA, four showed upregulation and activation of the AKT pathway following RFA, three studies demonstrated involvement of matrix metalloproteinases, and four showed upregulation of c-Met protein following RFA.

Conclusions

In our review and meta-analysis, we identify several proteins and pathways of interest of which are important in wound healing, angiogenesis, and cellular growth and survival. These proteins and pathways of interest may implicate areas of research towards RFA resistance and cancer recurrence.

Laser-Activatable In Situ Vaccine Enhances Cancer-Immunity Cycle

The immune response in cancer reflects a series of carefully regulated events; however, current tumor immunotherapies typically address a single key aspect to enhance anti-tumor immunity. In the present study, a nanoplatform (Fe3 O4 @IR820@CpG)-based immunotherapy strategy that targets the multiple key steps in cancer-immunity cycle is developed: 1) promotes the release of tumor-derived proteins (TDPs), including tumor-associated antigens and pro-immunostimulatory factors), in addition to the direct killing effect, by photothermal (PTT) and photodynamic therapy (PDT); 2) captures the released TDPs and delivers them, together with CpG (a Toll-like receptor 9 agonist) to antigen-presenting cells (APCs) to promote antigen presentation and T cell activation; 3) enhances the tumor-killing ability of T cells by combining with anti-programmed death ligand 1 antibody (α-PD-L1), which collectively advances the outstanding of the anti-tumor effects on colorectal, liver and breast cancers. The broad-spectrum anti-tumor activity of Fe3 O4 @IR820@CpG with α-PD-L1 demonstrates that optimally manipulating anti-cancer immunity not singly but as a group provides promising clinical strategies.

Radiofrequency Ablation-Induced Tumor Growth Is Suppressed by MicroRNA-21 Inhibition in Murine Models of Intrahepatic Colorectal Carcinoma

PURPOSE

To investigate the role of microRNA-21 (miR21) in radiofrequency (RF) ablation-induced tumor growth and whether miR21 inhibition suppresses tumorigenesis.

MATERIAL AND METHODS

Standardized liver RF ablation was applied to 35 C57/BL6 mice. miR21 and target proteins pSTAT3, PDCD4, and PTEN were assayed 3 hours, 24 hours, and 3 days after ablation. Next, 53 Balb/c and 44 C57BL/6 mice received Antago-miR21 or scrambled Antago-nc control, followed by intrasplenic injection of 10,000 CT26 or MC38 colorectal tumor cells, respectively. Hepatic RF ablation or sham ablation was performed 24 hours later. Metastases were quantified and tumor microvascular density (MVD) and cellular proliferation were assessed at 14 or 21 days after the procedures, respectively.

RESULTS

RF ablation significantly increased miR21 levels in plasma and hepatic tissue at 3 and 24 hours as well as target proteins at 3 days after ablation (P < .05, all comparisons). RF ablation nearly doubled tumor growth (CT26, 2.0 SD ± 1.0 fold change [fc]; MC38, 1.9 SD ± 0.9 fc) and increased MVD (CT26, 1.9 SD ± 1.0 fc; MC38, 1.5 ± 0.5 fc) and cellular proliferation (CT26, 1.7 SD ± 0.7 fc; MC38, 1.4 SD ± 0.5 fc) compared with sham ablation (P < .05, all comparisons). RF ablation-induced tumor growth was suppressed when Antago-miR21 was administered (CT26, 1.0 SD ± 0.7 fc; MC38, 0.9 SD ± 0.4 fc) (P < .01, both comparisons). Likewise, Antago-miR21 decreased MVD (CT26, 1.0 SD ± 0.3 fc; MC38, 1.0 SD ± 0.2 fc) and cellular proliferation (CT26, 0.9 SD ± 0.3 fc; MC38, 0.8 SD ± 0.3 fc) compared with baseline (P < .05, all comparisons).

CONCLUSIONS

RF ablation upregulates protumorigenic miR21, which subsequently influences downstream tumor-promoting protein pathways. This effect can potentially be suppressed by specific inhibition of miR21, rendering this microRNA a pivotal and targetable driver of tumorigenesis after hepatic thermal ablation.

Fibroblast growth factors induce hepatic tumorigenesis post radiofrequency ablation

Image-guided radiofrequency ablation (RFA) is used to treat focal tumors in the liver and other organs. Despite potential advantages over surgery, hepatic RFA can promote local and distant tumor growth by activating pro-tumorigenic growth factor and cytokines. Thus, strategies to identify and suppress pro-oncogenic effects of RFA are urgently required to further improve the therapeutic effect. Here, the proliferative effect of plasma of Hepatocellular carcinoma or colorectal carcinoma patients 90 min post-RFA was tested on HCC cell lines, demonstrating significant cellular proliferation compared to baseline plasma. Multiplex ELISA screening demonstrated increased plasma pro-tumorigenic growth factors and cytokines including the FGF protein family which uniquely and selectively activated HepG2. Primary mouse and immortalized human hepatocytes were then subjected to moderate hyperthermia in-vitro, mimicking thermal stress induced during ablation in the peri-ablational normal tissue. Resultant culture medium induced proliferation of multiple cancer cell lines. Subsequent non-biased protein array revealed that these hepatocytes subjected to moderate hyperthermia also excrete a similar wide spectrum of growth factors. Recombinant FGF-2 activated multiple cell lines. FGFR inhibitor significantly reduced liver tumor load post-RFA in MDR2-KO inflammation-induced HCC mouse model. Thus, Liver RFA can induce tumorigenesis via the FGF signaling pathway, and its inhibition suppresses HCC development.

Myofibroblasts: A key promoter of tumorigenesis following radiofrequency tumor ablation

Radiofrequency ablation (RFA) of intrahepatic tumors induces distant tumor growth through activation of interleukin 6/signal transducer and activator of transcription 3 (STAT3)/hepatocyte growth factor (HGF)/tyrosine-protein kinase Met (c-MET) pathway. Yet, the predominant cellular source still needs to be identified as specific roles of the many types of periablational infiltrating immune cells requires further clarification. Here we report the key role of activated myofibroblasts in RFA-induced tumorigenesis and successful pharmacologic blockade. Murine models simulating RF tumorigenic effects on a macrometastatic tumor and intrahepatic micrometastatic deposits after liver ablation and a macrometastatic tumor after kidney ablation were used. Immune assays of ablated normal parenchyma demonstrated significantly increased numbers of activated myofibroblasts in the periablational rim, as well as increased HGF levels, recruitment other cellular infiltrates; macrophages, dendritic cells and natural killer cells, HGF dependent growth factors; fibroblast growth factor-19 (FGF-19) and receptor of Vascular Endothelial Growth Factor-1 (VEGFR-1), and proliferative indices; Ki-67 and CD34 for microvascular density. Furthermore, macrometastatic models demonstrated accelerated distant tumor growth at 7d post-RFA while micrometastatic models demonstrated increased intrahepatic deposit size and number at 14 and 21 days post-RFA. Multi-day atorvastatin, a selective fibroblast inhibitor, inhibited RFA-induced HGF and downstream growth factors, cellular markers and proliferative indices. Specifically, atorvastatin treatment reduced cellular and proliferative indices to baseline levels in the micrometastatic models, however only partially in macrometastatic models. Furthermore, adjuvant atorvastatin completely inhibited accelerated growth of macrometastasis and negated increased micrometastatic intrahepatic burden. Thus, activated myofibroblasts drive RF-induced tumorigenesis at a cellular level via induction of the HGF/c-MET/STAT3 axis, and can be successfully pharmacologically suppressed.

The study of direct and indirect effects of radiofrequency ablation on tumor microenvironment in liver tumor animal model

BACKGROUND

Direct and indirect effects of radiofrequency ablation (RFA) on tumor microenvironment of the liver tumor have been noted, which was reported to be related to a variety of tyrosine protein kinase or cytokinetic pathway, but have not been thoroughly investigated and conclusive.

PURPOSE

To elucidate direct and indirect effects of RFA on tumor microenvironment in the liver tumor model, and to explore the role of the specific inhibitor in tumor growth by targeting the key pathway of RFA.

MATERIALS AND METHODS

One hundred and ten mice with H22 liver tumor were used in animal experiments. Eighty-four mice were randomized into three groups: control, direct RFA and indirect RFA (a block slide was inside the middle of the tumor). The growth rate of the residual tumor after RFA was calculated (n = 8 each group) and the pathologic changes at different time points (6 h, 24 h, 72 h and 7d after RFA) were evaluated (n = 5 in each subgroup). After semi-quantitative analysis of the pathological staining, the most significant marker after RFA was selected. Then, the specific inhibitor (PHA) was applied with RFA and the tumor growth and pathological changes were evaluated and compared with RFA alone. The Kruskal-Wallis test was used for evaluating the significance of different treatments in the pathological positive rate of specific markers in tumor. The two-way analysis of variance was used to determine the significance of treatment in tumor growth or body weight.

RESULTS

The growth rate of the residual tumor in the direct RFA group was faster than the indirect RFA group (P = 0.026). The pathological analysis showed the expression of HSP70 (73 ± 13% vs 27 ± 9% at 24 h, P < 0.001), SMA (70 ± 18% vs 18 ± 7% at 6 h, P < 0.001) and Ki-67 (51 ± 11% vs 33 ± 14% at 7d, P < 0.001) in the direct RFA group was higher than those in the indirect RFA group after RFA. On the other hand, the expression of c-Met (38 ± 11% vs 28 ± 9% at 24 h, P = 0.01), IL-6 (41 ± 10% vs 25 ± 9% at 24 h, P < 0.001) and HIF-α (48 ± 10% vs 28 ± 8% at 24 h, P < 0.001) in the indirect RFA group was higher than those in the direct RFA group. And the expression of c-Met increased mostly in both direct and indirect RFA group compared to the baseline (53 and 65% at 72 h). Then the specific inhibitor of c-Met-PHA was applied with RFA. The growth rate of the tumor was significantly slower in the RFA + PHA group than the RFA alone group (1112.9 ± 465.6 mm3 vs 2162.7 ± 911.1 mm3 at day 16, P = 0.02).

CONCLUSION

Direct and indirect effects of RFA on tumor microenvironment changed at different time points and resulted in increased residual tumor growth in the animal model. It can be potentially neutralized with specific inhibitor of related pathways, such as tyrosine-protein kinase c-Met.

Can two-step ablation combined with chemotherapeutic liposomes achieve better outcome than traditional RF ablation? A solid tumor animal study

Objectives: To determine whether two-step ablation using sequential low and high temperature heating can achieve improved outcomes in animal tumor models when combined with chemotherapeutic liposomes (LP). Materials and methods: Balb/c mice bearing 4T1 tumor received paclitaxel-loaded liposomes followed 24 h later by either traditional RFA (70 °C, 5 min) or a low temperature RFA (45 °C, 5 min), or two-step RFA (45 °C 2 min + 70 °C 3 min). Intratumoral drug accumulation and bio-distribution in major organs were evaluated. Periablational drug penetration was evaluated by pathologic staining and the intratumoral interstitial fluid pressure (IFP) was measured directly. For long-term outcomes, mice bearing 4T1 or H22 tumors were randomized into five groups (n = 8 per group): control (no treatment), RFA alone, LP + RFA (45 °C), LP + RFA (70 °C) and LP + RFA (45 + 70 °C). End-point survivals were compared among the different groups. Results: The greater intratumoral drug accumulation (3.35 ± 0.32 vs. 3.79 ± 0.29 × 108 phot/cm2/s at 24 h, p = 0.09), deeper periablational drug penetration (45.7 ± 5.0 vs. 1.6 ± 0.5, p < 0.001), and reduced off-target drug deposition in major organs (liver 96.1 ± 31.6 vs. 47.4 ± 1.5 × 106 phot/cm2/s, p < 0.001) were found when combined with RFA (45 °C) compared to drug alone. For long-term outcomes, 4T1 tumor growth rates for LP + two-step RFA (45 + 70 °C) were significantly slower than those of LP + RFA (70 °C), LP + RFA (45 °C), and RFA alone (P < 0.01 for all comparisons). End point survival for LP + RFA (45 + 70 °C) was also longer than that for LP + RFA (70 °C) (median 16 vs. 10 days, p = 0.003) or LP + RFA 45 °C (11 days, p = 0.009) and RFA alone (8.3 days, p < 0.001) in 4T1 tumor models. The intratumoral IFP after RFA (45 °C) was significantly lower than baseline RFA (3.3 ± 0.8 vs. 19.2 ± 3.1 mmHg, p < 0.001), but was not measurable after RFA (70 °C). Conclusions: A two-step ablation combined with chemotherapeutic liposomes can achieve better survival benefit compared to traditional RFA in animal models.

Colorectal liver metastasis: molecular mechanism and interventional therapy

Colorectal cancer (CRC) is one of the most frequently occurring malignancy tumors with a high morbidity additionally, CRC patients may develop liver metastasis, which is the major cause of death. Despite significant advances in diagnostic and therapeutic techniques, the survival rate of colorectal liver metastasis (CRLM) patients remains very low. CRLM, as a complex cascade reaction process involving multiple factors and procedures, has complex and diverse molecular mechanisms. In this review, we summarize the mechanisms/pathophysiology, diagnosis, treatment of CRLM. We also focus on an overview of the recent advances in understanding the molecular basis of CRLM with a special emphasis on tumor microenvironment and promise of newer targeted therapies for CRLM, further improving the prognosis of CRLM patients.

HCC: role of pre- and post-treatment tumor biology in driving adverse outcomes and rare responses to therapy

Liver cancer is the fastest-growing cause of cancer deaths in the United States and is a complex disease. The response of hepatocellular carcinoma (HCC) to treatment can be variable. Predicting response to determine the most effective therapy is an active area of research. Our understanding of underlying factors which drive response to therapy is continually increasing. As more therapies for the treatment of this disease evolve, it is crucial to identify and match the ideal therapy for a particular tumor and patient. The potential predicative imaging features of tumor behavior, while of research interest, have not been validated for clinical use and do not currently inform treatment planning. If further validated though, prognostic features may be used in the future to personalize treatment plans according to individual patients and tumors. Unexpected post-treatment responses such as potential tumor biology changes and abscopal effect which are important to be aware of. This review is intended for radiologists who routinely interpret post treatment HCC imaging and is designed to increase their cognizance about how HCC tumor biology drives response to therapy and explore rare responses to therapy.

The two facets of gp130 signalling in liver tumorigenesis

The liver is a vital organ with multiple functions and a large regenerative capacity. Tumours of the liver are the second most frequently cause of cancer-related death and develop in chronically inflamed livers. IL-6-type cytokines are mediators of inflammation and almost all members signal via the receptor subunit gp130 and the downstream signalling molecule STAT3. We here summarize current knowledge on how gp130 signalling and STAT3 in tumour cells and cells of the tumour micro-environment drives hepatic tumorigenesis. We furthermore discuss very recent findings describing also anti-tumorigenic roles of gp130/STAT3 and important considerations for therapeutic interventions.

Monitoring radiofrequency therapy-induced tumor cell dissemination by in vivo flow cytometry

Clinical and experimental findings have disclosed a high recurrence rate after radiofrequency ablation (RFA), which might be due to the dissemination of malignant cells into the vasculature during ablation. Here, we apply in vivo flow cytometry (IVFC) to monitor circulating tumor cells (CTCs) while performing ablation in a real-time and noninvasive way in an orthotopic model of prostate cancer. We report that CTCs are dramatically increased during RFA. The CTCs induced by ablation eventually translate into enhanced distant metastasis and reduced survival as compared to resection. Immunofluorescence analysis reveals that RFA significantly increases the infiltration of tumor-associated macrophages (TAMs) in the lung. Our study thus suggests that the ablative procedure of prostate tumors causes immediate tumor cell dissemination and increases distant metastasis.

MicroRNA-206 inhibits the proliferation, migration and invasion of colorectal cancer cells by regulating the c-Met/AKT/GSK-3β pathway

An imbalance in microRNA (miRNA/miR) expression is closely associated with tumorigenesis and progression. miR-206 is downregulated in different types of tumors, including colorectal cancer (CRC). However, the effects of miR-206 on the progression of CRC, and its underlying molecular mechanisms are yet to be elucidated. The present study aimed to investigate the effects of miR-206 on the proliferation, migration and invasion of colorectal cancer cells, and determine its potential molecular mechanism. The results of the present study demonstrated that the expression levels of miR-206 and c-Met were affected in HCT116 and SW480 cells by transfected with miR-206 mimic, inhibitor or small interfering RNA-c-Met. A Dual-luciferase reporter assay was performed to identify the miRNA targets. Cell proliferation, migration and invasion assays were also performed. The results demonstrated that overexpression of miR-206 significantly decreased the viability of HCT116 and SW480 cells. The results of the Transwell assay indicated that the cell migratory and invasive abilities were inhibited following transfection with miR-206 mimic. As a target of miR-206, knockdown of c-Met significantly suppressed cell viability, migration and invasion. In addition, c-Met knockdown or overexpression of miR-206 inhibited activation of the AKT/GSK-3β pathway. Collectively, these results suggest that miR-206 suppresses the proliferation, migration and invasion of CRC cells by targeting the c-Met/AKT/GSK-3β pathway.