Bevacizumab and rapamycin induce growth suppression in mouse models of hepatocellular carcinoma

The role of VEGF in Cancer angiogenesis and tumorigenesis: Insights for anti-VEGF therapy

Vascular endothelial growth factor (VEGF) is a critical regulator of angiogenesis, playing a pivotal role in both physiological and pathological processes. It promotes the formation of new blood vessels and activates downstream signaling pathways that regulate endothelial cell function. This review highlights recent advancements in the understanding of VEGF's molecular structure and its isoforms, as well as their implications in disease progression. It also explores the mechanisms of VEGF inhibitors. While VEGF inhibitors show promise in the treatment of cancer and other diseases, their clinical use faces significant challenges, including drug resistance, side effects, and complex interactions with other signaling pathways. To address these challenges, future research should focus on: (i) enhancing the understanding of VEGF subtypes and their distinct roles in various diseases, supporting the development of personalized treatment strategies; (ii) developing combination therapies that integrate VEGF inhibitors with other targeted treatments to overcome resistance and improve efficacy; (iii) optimizing drug delivery systems to reduce off-target effects and enhance therapeutic outcomes. These approaches aim to improve the effectiveness and safety of VEGF-targeted therapies, offering new possibilities for the treatment of VEGF-related diseases.

Rapamycin inhibits hepatitis B virus covalently closed circular DNA transcription by enhancing the ubiquitination of HBx

Hepatitis B virus (HBV) infection is still a serious public health problem worldwide. Antiviral therapies such as interferon and nucleos(t)ide analogs efficiently control HBV replication, but they cannot eradicate chronic hepatitis B (CHB) because of their incapacity to eliminate endocellular covalently closed circular DNA (cccDNA). Thus, there is a necessity to develop new strategies for targeting cccDNA. As cccDNA is difficult to clear, transcriptional silencing of cccDNA is a possible effective strategy. HBx plays a vitally important role in maintaining the transcriptional activity of cccDNA and it could be a target for blocking the transcription of cccDNA. To screen new drugs that may contribute to antiviral therapy, the ability of 2,000 small-molecule compounds to inhibit HBx was examined by the HiBiT lytic detection system. We found that the macrolide compound rapamycin, which is clinically used to prevent acute rejection after organ transplantation, could significantly reduce HBx protein expression. Mechanistic studies demonstrated that rapamycin decreased the stability of the HBx protein by promoting its degradation via the ubiquitin-proteasome system. Moreover, rapamycin inhibited HBV RNA, HBV DNA, and cccDNA transcription levels in HBV-infected cells. In addition, HBx deficiency abrogated the inhibition of cccDNA transcription induced by rapamycin. Similar results were also confirmed in a recombinant cccDNA mouse model. In summary, we report a new small-molecule, rapamycin, which targets HBx to block HBV cccDNA transcription and inhibit HBV replication. This approach can identify new strategies to cure CHB.

Relationship between Intestinal Microflora and Hepatocellular Cancer Based on Gut-Liver Axis Theory

The intestinal microflora is a bacterial group that lives in the human digestive tract and has a long-term interdependence with the host. Due to the close anatomical and functional relationship between the liver and the intestine, the intestinal flora affects liver metabolism via the intestinal-hepatic circulation, thereby playing an extremely important role in the pathological process of liver inflammation, chronic fibrosis, and liver cancer. In recent years, the rapid development of technologies in high-throughput sequencing and genomics has opened up possibilities for a broader and deeper understanding of the crosstalk between the intestinal flora and the occurrence and development of liver cancer. This review aims to summarize the mechanisms by which the gut microbiota changes the body's metabolism, through the gut-liver axis, thereby affecting the occurrence and development of primary liver cancer. In addition, the potential regulation of intestinal microflora in the treatment of liver cancer is discussed.

Patient-derived xenograft models in hepatopancreatobiliary cancer

Animal models are crucial tools for evaluating the biological progress of human cancers and for the preclinical investigation of anticancer drugs and cancer prevention. Various animals are widely used in hepatopancreatobiliary cancer research, and mouse models are the most popular. Generally, genetic tools, graft transplantation, and chemical and physical measures are adopted to generate sundry mouse models of hepatopancreatobiliary cancer. Graft transplantation is commonly used to study tumour progression. Over the past few decades, subcutaneous or orthotopic cell-derived tumour xenograft models (CDX models) have been developed to simulate distinct tumours in patients. However, two major limitations exist in CDX models. One model poorly simulates the microenvironment of tumours in humans, such as the vascular, lymphatic and immune environments. The other model loses genetic heterogeneity compared with the corresponding primary tumour. Increased efforts have focused on developing better models for hepatopancreatobiliary cancer research. Hepatopancreatobiliary cancer is considered a tumour with high molecular heterogeneity, making precision medicine challenging in cancer treatment. Developing a new animal model that can better mimic tumour tissue and more accurately predict the efficacy of anticancer treatments is urgent. For the past several years, the patient-derived xenograft model (PDX model) has emerged as a promising tool for translational research. It can retain the genetic and histological stability of their originating tumour at limited passages and shed light on precision cancer medicine. In this review, we summarize the methodology, advantages/disadvantages and applications of PDX models in hepatopancreatobiliary cancer research.

Novel molecular targets in hepatocellular carcinoma

Globally, hepatocellular carcinoma (HCC) is a leading cause of cancer and cancer-related deaths. The therapeutic efficacy of locoregional and systemic treatment in patients with advanced HCC remains low, which results in a poor prognosis. The development of sorafenib for the treatment of HCC has resulted in a new era of molecular targeted therapy for this disease. However, the median overall survival was reported to be barely higher in the sorafenib treatment group than in the control group. Hence, in this review we describe the importance of developing more effective targeted therapies for the management of advanced HCC. Recent investigations of molecular signaling pathways in several cancers have provided some insights into developing molecular therapies that target critical members of these signaling pathways. Proteins involved in the Hedgehog and Notch signaling pathways, Polo-like kinase 1, arginine, histone deacetylases and Glypican-3 can be potential targets in the treatment of HCC. Monotherapy has limited therapeutic efficacy due to the development of inhibitory feedback mechanisms and induction of chemoresistance. Thus, emphasis is now on the development of personalized and combination molecular targeted therapies that can serve as ideal therapeutic strategies for improved management of HCC.

Supramolecular Engineering of Molecular Inhibitors in an Adaptive Cytotoxic Nanoparticle for Synergistic Cancer Therapy

Combinatorial regimens that rationally pair molecular inhibitors with standard cytotoxic chemotherapeutics are used to improve therapeutic outcomes. Simultaneously engineering these therapies within a single nanocarrier that spans cytotoxic, antiangiogenic, and anti-invasive mechanisms and that enables the delivery of unique drug combinations remains a technical challenge. In this study, we developed a simple and broadly applicable strategy in which ultrastable cytotoxic nanoparticles with an established excellent antitumor efficacy and π-rich inner core structure supramolecularly stabilized the antiangiogenic molecular inhibitor apatinib to create a synergistic drug delivery system (termed sTKI-pSN38). This small-sized nanoparticle accomplished the sequential release of both encapsulated drugs to exert antimetastatic, antivascular, and cytotoxic activities simultaneously. In xenograft models of hepatocellular carcinoma, a single intravenous administration of sTKI-pSN38 elicited robust and durable tumor reduction and suppressed metastasis to lymph nodes. Interestingly, sTKI-pSN38 treatment alleviated intratumoral hypoxia, which could contribute to impaired tumor metastasis and reduced drug resistance. Collectively, this nanotherapeutic platform offers a new strategy for cancer therapy by simply engineering a drug cocktail in conventional nanoparticles and by enabling the spatiotemporal modulation of drug release to enhance the synergy of the combined drugs.

Targeting the mTOR regulatory network in hepatocellular carcinoma: Are we making headway?

The mechanistic target of rapamycin (mTOR) pathway coordinates organismal growth and homeostasis in response to growth factors, nutrients, and cellular energy stage. The pathway regulates several major cellular processes and is implicated in various pathological conditions, including hepatocellular carcinoma (HCC). This review summarizes recent advances of the mTOR pathway, highlights the potential of the mTOR pathway as a therapeutic target, and explores clinical trials targeting the mTOR pathway in HCC. Although the review focuses on the mTOR pathway involved in HCC, more comprehensive discussions (eg, developing a rational design for future trials targeting the mTOR pathway) are also applicable to other tumors.

Sorafenib/MEK inhibitor combination inhibits tumor growth and the Wnt/β‑catenin pathway in xenograft models of hepatocellular carcinoma

Mutations affecting the Wnt/β‑catenin pathway have been identified in 26‑40% of hepatocellular carcinoma (HCC) cases. Aberrant activation of this pathway leads to uncontrolled cell proliferation and survival. Thus, identifying Wnt/β‑catenin pathway inhibitors may benefit a subset of patients with HCC. In the present study, the effects of sorafenib and a MEK inhibitor on tumor growth and Wnt/β‑catenin signaling in HCC models were evaluated. A β‑catenin mutant and β‑catenin wild‑type HCC models were treated once daily with i) 10 mg/kg sorafenib, ii) 15 mg/kg refametinib (or 25 mg/kg selumetinib), or iii) sorafenib/refametinib. Western blotting was employed to determine changes in biomarkers relevant to Wnt/β‑catenin signaling. Apoptosis, cell proliferation and β‑catenin localization were analyzed by immunohistochemistry. Sorafenib/refametinib markedly inhibited tumor growth and cell proliferation, and caused cell death in naïve and sorafenib‑resistant HCC models. Despite similar total β‑catenin levels, significant reductions in phosphorylated (p)‑RanBP3 Ser58, p‑β‑catenin Tyr142, active β‑catenin and β‑catenin target genes were observed in sorafenib/refametinib‑treated tumors. Greater levels of β‑catenin in sorafenib/refametinib‑treated tumors were accumulated at the membrane, as compared with in the control. In vitro, sorafenib/refametinib inhibited the Wnt/β‑catenin pathway and suppressed Wnt‑3A‑induced p‑low‑density lipoprotein receptor‑related protein 6 Ser1490, p‑RanBP3 Ser58 and p‑β‑catenin Tyr142 in HCC cells. Combination of sorafenib and refametinib inhibits the growth of naïve and sorafenib resistant HCC tumors in association with active suppression of β‑catenin signaling regardless of β‑catenin mutational status. Thus, the sorafenib/MEK inhibitor combination may represent an alternative treatment for patients with HCC whose tumors develop resistance to sorafenib therapy.

Comparative Effectiveness of an mTOR-Based Systemic Therapy Regimen in Advanced, Metaplastic and Nonmetaplastic Triple-Negative Breast Cancer

BACKGROUND

Triple-negative breast cancer (TNBC) is a heterogeneous disease with subtypes having different "targetable" molecular aberrations. Metaplastic breast cancers (MpBCs) are typically TNBCs and commonly have alterations in the PI3K/Akt/mTOR pathway. We previously reported efficacy for an mTOR-based chemotherapy regimen in MpBC. To determine if tumor subtype influences prognosis, we compared treatment outcomes of patients with MpBC with those of patients with nonmetaplastic TNBC receiving an mTOR-based systemic therapy regimen.

PATIENTS AND METHODS

Patients with advanced MpBC and nonmetaplastic TNBC were treated at our institution from April 16, 2009, through November 4, 2014, using mTOR inhibition (temsirolimus or everolimus) with liposomal doxorubicin and bevacizumab (DAT/DAE). Median progression-free survival (PFS) and overall survival (OS) were estimated by the Kaplan-Meier method. Cox regression analyses were used to evaluate associations between tumor histology and outcomes. Multivariable models were adjusted for all covariates.

RESULTS

Fourteen patients with nonmetaplastic TNBC and 59 patients with advanced MpBC were treated with DAT/DAE. MpBC patients were older (p = .002) and less likely to have a history of bevacizumab use (p = .023). Median PFS for the nonmetaplastic TNBC and MpBC patients was 2.5 months and 4.8 months, respectively. This difference in PFS was statistically significant on univariable (p = .006) but not multivariable analysis (p = .087). Median OS for the nonmetaplastic TNBC and MpBC patients was 3.7 months and 10.0 months, respectively (p = .0003). MpBC remained significantly associated with improved OS on multivariable analysis (p < .0001).

CONCLUSION

In our study, DAT/DAE appeared to be more effective in MpBC compared with nonmetaplastic TNBC. These data support patient selection for targeted therapy in TNBC.

IMPLICATIONS FOR PRACTICE

Metaplastic breast cancers (MpBCs) represent <1% of all breast cancers, demonstrate mesenchymal differentiation, and are typically resistant to chemotherapy. Patients with advanced MpBC treated with an mTOR-based systemic therapy regimen had better long-term outcomes compared with patients with nonmetaplastic triple-negative breast cancer treated with the same regimen, suggesting that metaplastic histology may predict benefit from agents targeting the PI3K/Akt/mTOR pathway.

Sirolimus and metformin synergistically inhibit hepatocellular carcinoma cell proliferation and improve long-term survival in patients with HCC related to hepatitis B virus induced cirrhosis after liver transplantation

Immunosuppressive agents used postoperatively after liver transplantation (LT) for hepatocellular carcinoma (HCC) favor recurrence and metastasis. Therefore, new effective immunosuppressants are needed. This retrospective study assessed combined sirolimus and metformin on survival of HCC patients after LT. In 2001-2013, 133 HCC patients with LT were divided into four groups: sirolimus and metformin combination (Sir+Met), sirolimus monotherapy (Sir), other immunosuppressants in diabetes mellitus (DM) patients without metformin (No Sir with DM), and other immunosuppressants in patients without DM (No Sir without DM). Kaplan-Meier and Log-rank tests were used to assess survival. Cell proliferation and tumor xenograft assays were performed to disclose the mechanisms underlying the sirolimus and metformin effects. The Sir+Met group showed significantly prolonged survival compared to the other groups. The most significant cytotoxicity was seen in the Sir+Met group, with significantly decreased levels of phosphorylated PI3K, AKT, AMPK, mTOR, 4EBP1 and S6K, compared with the other groups. In agreement, Sir+Met had the highest suppressive effect on tumor growth among all groups (P<0.01). In summary, Sir+Met treatment significantly prolonged survival, likely by suppressing cell proliferation. Therefore, this combination could represent a potential routine-regimen for patients post LT.

Monitoring response to anti-angiogenic mTOR inhibitor therapy in vivo using 111In-bevacizumab

BACKGROUND

The ability to image vascular endothelial growth factor (VEGF) could enable prospective, non-invasive monitoring of patients receiving anti-angiogenic therapy. This study investigates the specificity and pharmacokinetics of 111In-bevacizumab binding to VEGF and its use for assessing response to anti-angiogenic therapy with rapamycin. Specificity of 111In-bevacizumab binding to VEGF was tested in vitro with unmodified radiolabelled bevacizumab in competitive inhibition assays. Uptake of 111In-bevacizumab in BALB/c nude mice bearing tumours with different amounts of VEGF expression was compared to that of isotype-matched control antibody (111In-IgG1κ) with an excess of unlabelled bevacizumab. Intratumoural VEGF was evaluated using ELISA and Western blot analysis. The effect of anti-angiogenesis therapy was tested by measuring tumour uptake of 111In-bevacizumab in comparison to 111In-IgG1κ following administration of rapamycin to mice bearing FaDu xenografts. Uptake was measured using gamma counting of ex vivo tumours and effect on vasculature by using anti-CD31 microscopy.

RESULTS

Specific uptake of 111In-bevacizumab in VEGF-expressing tumours was observed. Rapamycin led to tumour growth delay associated with increased relative vessel size (8.5 to 10.3, P = 0.045) and decreased mean relative vessel density (0.27 to 0.22, P = 0.0015). Rapamycin treatment increased tumour uptake of 111In-bevacizumab (68%) but not 111In-IgGκ and corresponded with increased intratumoural VEGF165.

CONCLUSIONS

111In-bevacizumab accumulates specifically in VEGF-expressing tumours, and changes after rapamycin therapy reflect changes in VEGF expression. Antagonism of mTOR may increase VEGF in vivo, and this new finding provides the basis to consider combination studies blocking both pathways and a way to monitor effects.

Evolving Significance and Future Relevance of Anti-Angiogenic Activity of mTOR Inhibitors in Cancer Therapy

mTOR inhibitors have demonstrated remarkable anti-tumor activity in experimental models, mainly by reducing cancer cell growth and tumor angiogenesis. Their use in cancer patients as monotherapy has, however, generated only limited benefits, increasing median overall survival by only a few months. Likewise, in other targeted therapies, cancer cells develop resistance mechanisms to overcome mTOR inhibition. Hence, novel therapeutic strategies have to be designed to increase the efficacy of mTOR inhibitors in cancer. In this review, we discuss the present and future relevance of mTOR inhibitors in cancer therapy by focusing on their effects on tumor angiogenesis.

Phosphorylated ERK is a potential prognostic biomarker for Sorafenib response in hepatocellular carcinoma

Sorafenib, the only approved drug for hepatocellular carcinoma, acts as a remarkable inhibitor of Raf serine‐threonine kinases. However, Sorafenib is expensive, and clinical experience shows that it is not an effective treatment for many patients. Previous study has demonstrated that phosphorylated ERK (pERK) is a key downstream component in the RAF/MEK/ERK signaling pathway. Here, we investigate whether pERK is a useful biomarker for treating HCC with Sorafenib. In vitro cell viability assays showed that the efficacy of Sorafenib was distinctly different according to the level of pERK. Furthermore, in established patient‐derived xenografts from HCC specimens, we found that the growth rate of tumors with high levels of pERK was significantly decreased by Sorafenib treatment. Taken together, pERK is a potential biomarker for the sensitivity to Sorafenib in treating HCC.

Patient-derived xenografts undergo mouse-specific tumor evolution

Patient-derived xenografts (PDXs) have become a prominent cancer model system, as they are presumed to faithfully represent the genomic features of primary tumors. Here we monitored the dynamics of copy number alterations (CNAs) in 1,110 PDX samples across 24 cancer types. We observed rapid accumulation of CNAs during PDX passaging, often due to selection of pre-existing minor clones. CNA acquisition in PDXs was correlated with the tissue-specific levels of aneuploidy and genetic heterogeneity observed in primary tumors. However, the particular CNAs acquired during PDX passaging differed from those acquired during tumor evolution in patients. Several CNAs recurrently observed in primary tumors gradually disappeared in PDXs, indicating that events undergoing positive selection in humans can become dispensable during propagation in mice. Importantly, the genomic stability of PDXs was associated with their response to chemotherapy and targeted drugs. These findings have important implications for PDX-based modeling of human cancer.

Hypoxia as a target for drug combination therapy of liver cancer

Hepatocellular carcinoma (HCC) is the third most frequent cause of cancer deaths worldwide. The standard of care for intermediate HCC is transarterial chemoembolization, which combines tumour embolization with locoregional delivery of the chemotherapeutic doxorubicin. Embolization therapies induce hypoxia, leading to the escape and proliferation of hypoxia-adapted cancer cells. The transcription factor that orchestrates responses to hypoxia is hypoxia-inducible factor 1 (HIF-1). The aim of this work is to show that targeting HIF-1 with combined drug therapy presents an opportunity for improving outcomes for HCC treatment. HepG2 cells were cultured under normoxic and hypoxic conditions exposed to doxorubicin, rapamycin and combinations thereof, and analyzed for viability and the expression of hypoxia-induced HIF-1α in response to these treatments. A pilot study was carried out to evaluate the antitumour effects of these drug combinations delivered from drug-eluting beads in vivo using an ectopic xenograft murine model of HCC. A therapeutic doxorubicin concentration that inhibits the viability of normoxic and hypoxic HepG2 cells and above which hypoxic cells are chemoresistant was identified, together with the lowest effective dose of rapamycin against normoxic and hypoxic HepG2 cells. It was shown that combinations of rapamycin and doxorubicin are more effective than doxorubicin alone. Western Blotting indicated that both doxorubicin and rapamycin inhibit hypoxia-induced accumulation of HIF-1α. Combination treatments were more effective in vivo than either treatment alone. mTOR inhibition can improve outcomes of doxorubicin treatment in HCC.

Exploring response signals and targets in aggressive unresectable hepatocellular carcinoma: an analysis of targeted therapy phase 1 trials

PURPOSE

Patients with advanced hepatocellular carcinoma (HCC) have limited effective therapeutic options. Given the rapid advanced in drug development and emergence of novel agents, we analyzed the characteristics and outcomes of HCC patients treated on early phase trials with an emphasis on targeted therapies.

METHODS

We reviewed the records of consecutive HCC patients evaluated in the Phase I Clinical Trials Program at MD Anderson from March 2004.

RESULTS

Thirty-nine patients were not treated due to poor performance status (n = 22, 56%) and decision to pursue alternate therapies (n = 10, 27%). Of 61 treated patients (median age, 60 years; median prior therapies, 3), eight patients (13%) attained stable disease lasting ≥6 months; four (7%) had a partial response, mainly with anti-angiogenic or multikinase inhibitors. Median Phase I progression-free survival (PFS) was 2.6 months versus 4.4 months (p 0.019) and 4.1 months (p 0.27) for their first-, and second-line FDA-approved therapy. Molecular analysis showed frequent PTEN loss (10/19 patients, 53%) and P53 mutation (4/4 patients tested). On multivariate analysis, independent factors predicting shorter survival were white ethnicity/race (p 0.031), cirrhosis (p 0.016), and serum sodium (p 0.0013).

CONCLUSIONS

In our heavily-pretreated HCC patients, the phase I PFS was comparable to that of 2^nd-line therapy, highlighting a potential role for clinical trials after progression on first-line therapy. The response rate (SD>6 months/PR) of 20% was observed with early signals of activity in regimens combining inhibitors of angiogenesis, multiple kinases and mTOR with preliminary molecular analysis revealing prevalence of PTEN loss.

Combination of bevacizumab and acyclic retinoid inhibits the growth of hepatocellular carcinoma xenografts

The prognosis of patients with hepatocellular carcinoma (HCC) is poor and the development of effective treatments for this malignancy, including combination chemotherapy, is required. This study examined the possible combined inhibitory effects of bevacizumab, an anti-vascular endothelial growth factor monoclonal antibody, and acyclic retinoid (ACR), which can prevent the development of HCC, on the growth of Huh7 human HCC cells. Xenograft tumors were produced by subcutaneously injecting Huh7 cells into nude mice. Starting 1 wk after the tumor cell injection, the mice were treated with bevacizumab alone (5 mg/kg body weight, subcutaneous injection, twice a week), ACR alone (given in a diet containing 0.03%), or their combination for 6 wk, and the effects of these regimens on xenograft growth were examined. Combined treatment with bevacizumab plus ACR significantly suppressed the growth of Huh7 xenografts. The combination of these agents significantly inhibited the phosphorylation of the Akt protein in tumor tissues. With combination therapy, the population of Ki-67-positive cells in xenografts decreased, while that of TUNEL-positive cells increased. The combination of bevacizumab and ACR exerts growth-suppressing effects on HCC cells by inhibiting cell proliferation and inducing apoptosis. This combination might be an effective regimen for the treatment of HCC.

Genomic characterization of a large panel of patient-derived hepatocellular carcinoma xenograft tumor models for preclinical development

Lack of clinically relevant tumor models dramatically hampers development of effective therapies for hepatocellular carcinoma (HCC). Establishment of patient-derived xenograft (PDX) models that faithfully recapitulate the genetic and phenotypic features of HCC becomes important. In this study, we first established a cohort of 65 stable PDX models of HCC from corresponding Chinese patients. Then we showed that the histology and gene expression patterns of PDX models were highly consistent between xenografts and case-matched original tumors. Genetic alterations, including mutations and DNA copy number alterations (CNAs), of the xenografts correlated well with the published data of HCC patient specimens. Furthermore, differential responses to sorafenib, the standard-of-care agent, in randomly chosen xenografts were unveiled. Finally, in the models expressing high levels of FGFR1 gene according to the genomic data, FGFR1 inhibitor lenvatinib showed greater efficacy than sorafenib. Taken together, our data indicate that PDX models resemble histopathological and genomic characteristics of clinical HCC tumors, as well as recapitulate the differential responses of HCC patients to the standard-of-care treatment. Overall, this large collection of PDX models becomes a clinically relevant platform for drug screening, biomarker discovery and translational research in preclinical setting.

A phase II trial of bevacizumab plus temsirolimus in patients with advanced hepatocellular carcinoma

BACKGROUND

There is strong rationale to combine temsirolimus (TEM) with Bevacizumab (BEV) for patients with advanced HCC.

METHODS

A modified two-stage Simon phase II trial was performed with plans to advance to stage 2 if more than 2 patients had confirmed PR or >18 patients were progression free at 6 months out of 25 in stage 1. Toxicity, PFS and overall survival were secondary endpoints. Eligible pts had advanced HCC, Child Pugh A liver status and no prior systemic therapy involving the VEGF or m-TOR targeted agents. Patients were treated with temsirolimus 25 mg IV on Days 1, 8, 15, and 22 of a 28 day cycle and bevacizumab 10 mg/kg IV on Days 1 and 15 of the cycle.

RESULTS

Twenty-eight eligible patients were enrolled, 26 evaluable receiving a median of 6.5 cycles (range 1-18). Drug related toxicities were common including cytopenias, fatigue, mucositis, diarrhea and mild bleeds. Dose reductions or discontinuation of TEM were common. Accrual closed for presumed futility after interim analysis of the first 25 evaluable patients showed only one PR and 16/25 were progression-free at 6 months. However, the final data update in March 2013 demonstrated 4 confirmed PRs, a 5th unconfirmed PR and 16 /26 progression-free at 6 months. Median PFS and OS were 7 and 14 months respectively.

CONCLUSION

This first-line HCC trial evaluating the BEV/TEM doublet reports an ORR of 19 % and OS of 14 months which is favorable but requires further study at a more optimized dose and schedule.

HRES-1/Rab4-mediated depletion of Drp1 impairs mitochondrial homeostasis and represents a target for treatment in SLE

OBJECTIVE

Accumulation of mitochondria underlies T-cell dysfunction in systemic lupus erythematosus (SLE). Mitochondrial turnover involves endosomal traffic regulated by HRES-1/Rab4, a small GTPase that is overexpressed in lupus T cells. Therefore, we investigated whether (1) HRES-1/Rab4 impacts mitochondrial homeostasis and (2) Rab geranylgeranyl transferase inhibitor 3-PEHPC blocks mitochondrial accumulation in T cells, autoimmunity and disease development in lupus-prone mice.

METHODS

Mitochondria were evaluated in peripheral blood lymphocytes (PBL) of 38 SLE patients and 21 healthy controls and mouse models by flow cytometry, microscopy and western blot. MRL/lpr mice were treated with 125 μg/kg 3-PEHPC or 1 mg/kg rapamycin for 10 weeks, from 4 weeks of age. Disease was monitored by antinuclear antibody (ANA) production, proteinuria, and renal histology.

RESULTS

Overexpression of HRES-1/Rab4 increased the mitochondrial mass of PBL (1.4-fold; p=0.019) and Jurkat cells (2-fold; p=0.000016) and depleted the mitophagy initiator protein Drp1 both in human (-49%; p=0.01) and mouse lymphocytes (-41%; p=0.03). Drp1 protein levels were profoundly diminished in PBL of SLE patients (-86±3%; p=0.012). T cells of 4-week-old MRL/lpr mice exhibited 4.7-fold over-expression of Rab4A (p=0.0002), the murine homologue of HRES-1/Rab4, and depletion of Drp1 that preceded the accumulation of mitochondria, ANA production and nephritis. 3-PEHPC increased Drp1 (p=0.03) and reduced mitochondrial mass in T cells (p=0.02) and diminished ANA production (p=0.021), proteinuria (p=0.00004), and nephritis scores of lupus-prone mice (p<0.001).

CONCLUSIONS

These data reveal a pathogenic role for HRES-1/Rab4-mediated Drp1 depletion and identify endocytic control of mitophagy as a treatment target in SLE.

Interferon-α enhances the susceptibility of renal cell carcinoma to rapamycin by suppressing mTOR activity

The aim of the present study was to investigate the antiproliferative effects of interferon (IFN)-α and rapamycin (RPM) on renal cell carcinoma (RCC) cells and examine the synergistic growth suppression conferred by IFN-α and RPM. The effects of IFN-α and/or RPM on RCC cells were determined using a WST-1 assay and the synergy of IFN-α and RPM against three RCC cell lines was analyzed with isobolographic analysis. The expression of mammalian target of rapamycin (mTOR) was downregulated by RNAi, and the expression and phosphorylation of proteins in the mTOR pathway following treatment with IFN-α and/or RPM was examined by western blot analysis. The observations indicated that IFN-α significantly increased the susceptibility of RCC cells to RPM and the synergistic effect of IFN-α and RPM against RCC cells was confirmed in all three RCC cell lines. The mTOR pathway was shown to be associated with the synergistic effect of IFN-α and RPM against RCC. IFN-α and RPM alone decreased the phosphorylation of mTOR, p70 S6 kinase, S6 and 4E binding protein 1, and IFN-α significantly enhanced the RPM-induced suppression of the mTOR pathway. However, in RCC cells with low mTOR activity, the synergy of IFN-α and RPM was eliminated. Therefore, the results of the present study indicate that the mTOR pathway plays an important role in the synergistic effect of IFN-α and RPM against RCC cells. Thus, mTOR may serve as an effective therapeutic target in the treatment of advanced RCC.

Transcriptional dissection of pancreatic tumors engrafted in mice

Background

Engraftment of primary pancreas ductal adenocarcinomas (PDAC) in mice to generate patient-derived xenograft (PDX) models is a promising platform for biological and therapeutic studies in this disease. However, these models are still incompletely characterized. Here, we measured the impact of the murine tumor environment on the gene expression of the engrafted human tumoral cells.

Methods

We have analyzed gene expression profiles from 35 new PDX models and compared them with previously published microarray data of 18 PDX models, 53 primary tumors and 41 cell lines from PDAC. The results obtained in the PDAC system were further compared with public available microarray data from 42 PDX models, 108 primary tumors and 32 cell lines from hepatocellular carcinoma (HCC). We developed a robust analysis protocol to explore the gene expression space. In addition, we completed the analysis with a functional characterization of PDX models, including if changes were caused by murine environment or by serial passing.

Results

Our results showed that PDX models derived from PDAC, or HCC, were clearly different to the cell lines derived from the same cancer tissues. Indeed, PDAC- and HCC-derived cell lines are indistinguishable from each other based on their gene expression profiles. In contrast, the transcriptomes of PDAC and HCC PDX models can be separated into two different groups that share some partial similarity with their corresponding original primary tumors. Our results point to the lack of human stromal involvement in PDXs as a major factor contributing to their differences from the original primary tumors. The main functional differences between pancreatic PDX models and human PDAC are the lower expression of genes involved in pathways related to extracellular matrix and hemostasis and the up- regulation of cell cycle genes. Importantly, most of these differences are detected in the first passages after the tumor engraftment.

Conclusions

Our results suggest that PDX models of PDAC and HCC retain, to some extent, a gene expression memory of the original primary tumors, while this pattern is not detected in conventional cancer cell lines. Expression changes in PDXs are mainly related to pathways reflecting the lack of human infiltrating cells and the adaptation to a new environment. We also provide evidence of the stability of gene expression patterns over subsequent passages, indicating early phases of the adaptation process.

mTOR in viral hepatitis and hepatocellular carcinoma: function and treatment

As the fifth most common cancer in men and the eighth most common cancer in women, hepatocellular carcinoma (HCC) is the leading cause of cancer-related deaths worldwide, with standard chemotherapy and radiation being minimally effective in prolonging survival. Virus hepatitis, particularly HBV and HCV infection is the most prominent risk factor for HCC development. Mammalian target of rapamycin (mTOR) pathway is activated in viral hepatitis and HCC. mTOR inhibitors have been tested successfully in clinical trials for their antineoplastic potency and well tolerability. Treatment with mTOR inhibitor alone or in combination with cytotoxic drugs or targeted therapy drug scan significantly reduces HCC growth and improves clinical outcome, indicating that mTOR inhibition is a promising strategy for the clinical management of HCC.

Metaplastic breast cancer: histologic characteristics, prognostic factors and systemic treatment strategies

Metaplastic breast cancer (MBC) is a rare subtype of invasive breast cancer that tends to have an aggressive clinical presentation as well as a variety of distinct histologic designations. Few systemic treatment options are available for MBC, as it has consistently shown a suboptimal response to standard chemotherapy regimens. These characteristics result in a worse overall prognosis for patients with MBC compared to those with standard invasive breast cancer. Due to its rarity, data focusing on MBC is limited. This review will discuss the clinical presentation, breast imaging findings, histologic and molecular characteristics of MBC as well as potential future research directions.

The evolving landscape of therapeutic drug development for hepatocellular carcinoma

Currently, only one drug, sorafenib, is FDA approved for the treatment of advanced hepatocellular carcinoma (HCC), achieving modest objective response rates while still conferring an overall survival benefit. Unlike other solid tumors, no oncogenic addiction loops have been validated as clinically actionable targets in HCC. Outcomes of HCC could potentially be improved if critical molecular subclasses with distinct therapeutic vulnerabilities can be identified, biomarkers that predict recurrence or progression early can be determined and key epigenetic, genetic or microenvironment drivers that determine best response to a specific targeting treatment can be uncovered. Our group and others have examined the molecular heterogeneity of hepatocellular carcinoma. We have developed a panel of patient derived xenograft models to enable focused pre-clinical drug development of rationally designed therapies in specific molecular subgroups. We observed unique patterns, including synergies, of drug activity across our molecularly diverse HCC xenografts, pointing to specific therapeutic vulnerabilities for individual tumors. These efforts inform clinical trial designs and catalyze therapeutic development. It also argues for efficient strategic allocation of patients into appropriate enriched clinical trials. Here, we will discuss some of the recent important therapeutic studies in advanced HCC and also some of the potential strategies to optimize clinical therapeutic development moving forward.

Dysfunctional activation of neurotensin/IL-8 pathway in hepatocellular carcinoma is associated with increased inflammatory response in microenvironment, more epithelial mesenchymal transition in cancer and worse prognosis in patients

Aim

To investigate the role of neurotensin (NTS) in hepatocellular carcinoma (HCC) sub- grouping and the clinical and pathological significance of activation of NTS/IL-8 pathway in HCC.

Methods

The genome-wide gene expression profiling were conducted in 10 pairs of cancer tissues and corresponding normal adjacent tissues samples using Affymetrix GeneChip® Human Genome U133 Plus 2.0 microarray to screen differentially expressing genes and enrich dysfunctional activated pathways among different HCC subgroups. The levels of NTS protein and multiple inflammation and epithelial mesenchymal transition (EMT) related proteins, including IL-8, VEGF, MMP9, CD68, E-Cadherin, β-Catenin and Vimentin were examined in 64 cases of paraffin-embedded HCC samples using immunohistochemistry (IHC) staining method. The clinical outcome and overall survival (OS) were compared.

Results

A subgroup of HCC characterized by up-regulated NTS expression was accompanied by up-regulated inflammatory responses and EMT. The direct interaction between NTS and IL-8 was identified by pathway enrichment analysis. Significantly increased IL-8 protein was confirmed in 90.91% of NTS⁺ HCC samples and significantly positively correlated to the levels of NTS protein in cancer tissues (P = 0.036), which implied activation of NTS/IL-8 pathway in HCC. The levels of VEGF and MMP9 correlated with co-expression of NTS and IL-8. Increased infiltration of CD68⁺ macrophages and more cancer cells displaying EMT features were found in NTS⁺IL-8⁺ samples. The co-expression of NTS and IL-8 in cancer significantly correlated with the clinical outcomes, as the mortality rate of NTS⁺IL-8⁺ HCC patients is 2.5-fold higher than the others after the surgery (P = 0.022). Accordingly, the OS of NTS⁺IL-8⁺ HCC patients significantly decreased who are under a higher hazard of death at an expected hazard ratio (HR) of 3.457.

Conclusion

Dysfunctional activation of the NTS/IL-8 pathway was detected in HCC which is associated with increased inflammatory response in microenvironment, enhanced EMT in cancer, and worse prognosis in HCC patients.

A Phase 1 dose-finding and pharmacodynamic study of rapamycin in combination with bevacizumab in patients with unresectable hepatocellular carcinoma

BACKGROUND & AIMS

Preclinical studies have demonstrated the additive effect of rapamycin with bevacizumab for hepatocellular carcinoma treatment. We conducted a Phase 1 study to evaluate the safety and pharmacokinetics of the combination in patients with hepatocellular carcinoma.

METHODS

Adult participants with advanced hepatocellular carcinoma received intravenous bevacizumab (5mg/kg every 14 days) and oral rapamycin (1-6 mg/day; 3+3 dose escalation design). Computed tomography assessed tumour response and treatment safety. Pharmacokinetics assessment established rapamycin blood concentrations pre- and post-dose. Dynamic contrast-enhanced computed tomography analysed the tumour region for blood flow, permeability surface area product, fractional intravascular blood volume and extracellular-extravascular volume.

RESULTS

Twenty-four participants were treated. There were two dose limiting toxicities with rapamycin 5mg: grade 3 thrombocytopenia and grade 3 mucositis. The maximally tolerated dose of rapamycin was 4 mg. Adverse events (grade 1-2) included hyperglycaemia (83%), thrombocytopenia (75%), fatigue (46%), mucositis (46%), anorexia (42%), diarrhoea (33%) and proteinuria (12.5%). Of 20 evaluable participants, one reached complete response that lasted 4.5 months, two reached partial response, 14 reached stable disease and three had progressive disease. Median overall survival was 9.4 months; progression-free survival was 5.5 months. Dose level and steady state area under the concentration time curve for hour zero to infinity of rapamycin correlated inversely with blood flow rate and change in permeability-surface area. After 22 days of treatment, there were significant reductions from baseline in blood flow rate, permeability-surface area and fractional intracellular blood volume.

CONCLUSIONS

The recommended Phase 2 dose of rapamycin is 4 mg in combination with bevacizumab. Evidence of anti-vascular activity was observed together with promising clinical activity.

Metronomic chemotherapy in combination with antiangiogenic treatment induces mosaic vascular reduction and tumor growth inhibition in hepatocellular carcinoma xenografts

BACKGROUND

In addition to sprouting angiogenesis, other mechanisms, such as mosaic tumor vessel formation, have been recognized to contribute to tumor vascularization. We sought to examine vascular alteration as well as tumor growth inhibition after treatment with antiangiogenic therapy, chemotherapy alone or in combination.

METHODS

Hepatocellular carcinoma cells (Hep3B) expressed green fluorescent protein were utilized to establish orthotopic xenograft model in nude mice. The formation and distribution of mosaic vessels was analyzed quantitatively by immunolabeling. Next, changes in tumor microcirculation and therapeutic effects on tumor growth were evaluated in several different treatment groups: control, conventional doxorubicin, metronomic doxorubicin, bevacizumab, bevacizumab plus conventional doxorubicin, and bevacizumab plus metronomic doxorubicin. In addition, we examined the effects of combined regimens on lung metastasis using a highly metastatic human hepatocellular carcinoma (HCCLM3) mouse model.

RESULTS

Approximately 62 % of the vessels were present in the central part or near the midsection of the tumor and were mosaic. Only the combined antiangiogenic treatment and chemotherapy (metronomic schedule, P = 0.00; conventional schedule, P = 0.02) had a significant effect on the degree of mosaic vasculature. Metronomic doxorubicin in combination with bevacizumab had an even more profound effect than bevacizumab plus conventional doxorubicin (P < 0.05) on tumor growth inhibition and survival. However, bevacizumab plus metronomic doxorubicin failed to inhibit lung metastasis compared with antiangiogenic monotherapy.

CONCLUSIONS

Metronomic chemotherapy in combination with antiangiogenic treatment results in the reduction of mosaic tumor vasculature, inhibition of tumor growth, and enhanced survival of mice. Further investigation of drug scheduling is required to optimize antitumor activity.

Systemic treatment and targeted therapy in patients with advanced hepatocellular carcinoma

BACKGROUND

ADVANCED HEPATOCELLULAR CARCINOMA (HCC) IS A MALIGNANCY OF GLOBAL IMPORTANCE: it is the sixth most common cancer and the third most common cause of cancer-related mortality worldwide. Despite decades of efforts by many investigators, systemic chemotherapy or hormone therapy has failed to demonstrate improved survival in patients with HCC.. Ongoing studies are evaluating the efficacy and tolerability of combining Sorafenib with erlotinib and other targeted agents or chemotherapy.

AIMS

On the basis of placebo-controlled, randomized phase III trials, Sorafenib has shown improved survival benefits in advanced HCC and has set a new standard for future clinical trials. The successful clinical development of Sorafenib in HCC has ushered in the era of molecularly targeted agents in this disease, which is discussed in this educational review.

MATERIAL AND METHODS

Many molecularly targeted agents that inhibit angiogenesis, epidermal growth factor receptor, and mammalian target of rapamycin are at different stages of clinical development in advanced HCC. Future research should continue to unravel the mechanism of hepatocarcinogenesis and to identify key relevant molecular targets for therapeutic intervention. Identification and validation of potential surrogate and predictive biomarkers hold promise to individualize patients' treatment to maximize clinical benefit and minimize the toxicity and cost of targeted agents.

RESULTS

Systemic therapy with various classes of agents, including hormone and cytotoxic agents, has provided no or marginal benefits. Improved understanding of the mechanism of hepatocarcinogenesis, coupled with the arrival of many newly developed molecularly targeted agents, has provided the unique opportunity to study some of these novel agents in advanced HCC.

CONCLUSIONS

The demonstration of improved survival benefits by Sorafenib in advanced HCC has ushered in the era of molecular-targeted therapy in this disease, with many agents undergoing active clinical development.

Hepatocellular carcinoma: insight from animal models

Hepatocellular carcinoma (HCC) ranks as the third most common cause of death from cancer worldwide. Although major risk factors for the development of HCC have been defined, many aspects of the evolution of hepatocellular carcinogenesis and metastasis are still unknown. Suitable animal models are, therefore, essential to promote our understanding of the molecular, cellular and pathophysiological mechanisms of HCC and for the development of new therapeutic strategies. This Review provides an overview of animal models that are relevant to HCC development, metastasis and treatment. For HCC development, this Review focuses on transgenic mouse models of HBV and HCV infection, which provide experimental evidence that viral genes could initiate or promote liver carcinogenesis. Animal models of HCC metastasis provide platforms to elucidate the mechanisms of HCC metastasis, to study the interaction between the microenvironment and HCC invasion and to conduct intervention studies. In addition, animal models have been developed to investigate the effects of new treatment modalities. The criteria for establishing ideal HCC animal models are also discussed.

Anti-VEGF and beyond: shaping a new generation of anti-angiogenic therapies for cancer

The anti-angiogenic class of drugs is one of the few where representatives have gained international approval for clinical use in oncology during the past decade. Most of the biological and clinical activity of the currently available generation of anti-angiogenic drugs targets vascular endothelial growth factor (VEGF) and its related pathways. However, the clinical benefits associated with the use of these drugs have, so far, been limited. There is, therefore, an unmet need for biomarkers that can be used to identify patients who are most likely to benefit therapeutically and also to predict the best schedule and dosage for these drugs. Here, we discuss some of the emerging new combination strategies involving the approved anti-angiogenic drugs, some of the emerging targets associated with neoplastic angiogenesis and some novel agents used as a paradigm of the next generation of anti-angiogenic drugs.

Inhibition of angiogenic and non-angiogenic targets by sorafenib in renal cell carcinoma (RCC) in a RCC xenograft model

Background:

It is widely recognised that sorafenib inhibits a range of molecular targets in renal cell carcinoma (RCC). In this study, we aim to use patient-derived RCC xenografts to delineate the angiogenic and non-angiogenic molecular targets of sorafenib therapy for advanced RCC (aRCC).

Methods:

We successfully generated three patient RCC-derived xenografts in severe combined immunodeficient mice, consisting of three different RCC histological subtypes: conventional clear cell, poorly differentiated clear cell RCC with sarcomatoid changes, and papillary RCC. This study also used clear cell RCC cells (786-0/EV) harbouring mutant VHL to investigate the clonogenic survival of cells transfected with survivin sense and antisense oligonucleotides.

Results:

All three xenografts retain their original histological characteristics. We reported that sorafenib inhibited all three RCC xenograft lines regardless of histological subtypes in a dose-dependant manner. Sorafenib-induced growth suppression was associated with not only inhibition of angiogenic targets p-PDGFR-β, p-VEGFR-2, and their downstream signalling pathways p-Akt and p-ERK, cell cycle, and anti-apoptotic proteins that include cyclin D1, cyclin B1, and survivin but also upregulation of proapoptotic Bim. Survivin knockdown by survivin-specific antisense-oligonucleotides inhibited colony formation and induced cell death in clear cell RCC cells.

Conclusion:

This study has shed light on the molecular mechanisms of sorafenib in RCC. Inhibition of non-angiogenic molecules by sorafenib could contribute in part to its anti-tumour activities observed in vivo, in addition to its anti-angiogenic effects.

Advances in molecularly targeted therapy of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a fatal disease that represents the fifth most common human cancer. Although remarkable progress has been achieved in HCC treatment in China, the overall incidence and mortality rates of HCC show no obvious changes. Pharmacological treatment can not improve the prognosis of patients with unresectable HCC. This emphasizes the need to identify new targets for early diagnosis, chemoprevention, and treatment of the disease. An effort to understand the molecular mechanisms responsible for tumor initiation and progression has led to the identification of several potential molecular targets for HCC. The majority of these targets are involved in receptor tyrosine kinase-activated pathways, such as the Raf/MEK/ERK, PI-3K/Akt/mTOR, and Jak/Stat pathways. Sorafenib is a multikinase inhibitor that has attracted wide attention. This review describes the potential targets for HCC and recent progress in targeted therapy of the disease.

Utilizing targeted cancer therapeutic agents in combination: novel approaches and urgent requirements

The rapid development of new therapeutic agents that target specific molecular pathways involved in tumour cell proliferation provides an unprecedented opportunity to achieve a much higher degree of biochemical specificity than previously possible with traditional chemotherapeutic anticancer agents. However, the lack of specificity of these established chemotherapeutic drugs allowed a relatively straightforward approach to their use in combination therapies. Developing a paradigm for combining new, molecularly targeted agents, on the other hand, is substantially more complex. The abundance of molecular data makes it possible, at least in theory, to predict how such agents might interact across crucial growth control networks. Initial strategies to examine molecularly targeted agent combinations have produced a small number of successes in the clinic. However, for most of these combination strategies, both in preclinical models and in patients, it is not clear whether the agents being combined actually hit their targets to induce growth inhibition. Here, we consider the initial approach of the US National Cancer Institute (NCI) to the evaluation of combinations of molecularly targeted anticancer agents in patients and provide a description of several new approaches that the NCI has initiated to improve the effectiveness of combination-targeted therapy for cancer.

Patient-derived human tumour tissue xenografts in immunodeficient mice: a systematic review

Mouse cancer models have consistently been used to qualify new anticancer drugs in the development of human clinical trials. Rodent tumour models currently being used and which include transgenic tumour models, and those generated by planting human tumour cell lines subcutaneously in immunodeficient mice, do not sufficiently represent clinical cancer characteristics, especially with regard to metastasis and drug sensitivity. The increasingly used patient-derived human tumour tissue (PDTT) xenografts models implanted subcutaneously or in subrenal capsule in immunodeficient mice, such as athymic nude mice or severe combined immunedeficient (SCID) mice, may provide a more accurate reflection of human tumour biological characteristics than tumour cell lines. The ability to passage patients' fresh tumour tissues into large numbers of immunodeficient mice provides possibilities for better preclinical testing of new therapies for the treatment and better outcome for cancer. In this review, we outline the methods of establishing xenograft models, discuss the biological stability of PDTT xenograft models and demonstrate their roles in developing new anticancer drugs and testing therapeutic regimens in cancer patients.

Personalized cancer therapy using a patient-derived tumor tissue xenograft model: a translational field worthy of exploring further?

It has long been observed that interpatient variability in response to anticancer drugs is associated with different outcomes. Oncologists continually hold the desire of matching the right therapeutic regimen with the right cancer patient, which is termed ‘personalized cancer therapy’. Rapid advances in genetics, genomics and related technologies are promising a new era of personalized cancer therapy based on individual molecular biomarkers. However, these molecular predictors of tumor response are far from perfect. Because of the inherent limitations in the current approaches for anticancer drugs response prediction, the need for new techniques to predict tumor response to therapy is urgent. Using a patient-derived human tumor tissue (PDTT) xenograft model to predict tumor response to therapy might be an ideal candidate method to choose. This article provides an overview of the achievements and limitations of genetic, genomic and proteomic molecular markers for personalized cancer therapy, and further discusses the potentials of using a PDTT xenograft model as a candidate strategy for personalized cancer therapy.

Hepatocellular carcinoma: consensus recommendations of the National Cancer Institute Clinical Trials Planning Meeting

Hepatocelluar carcinoma (HCC) is the most common primary malignancy of the liver in adults and the third most common cause of cancer death worldwide. The incidence of HCC in the United States is rising steadily because of the prevalence of hepatitis C viral infection and other causes of hepatic cirrhosis. The majority of patients have underlying hepatic dysfunction, which complicates patient management and the search for safe and effective therapies. The Clinical Trials Planning Meeting (CTPM) in HCC was convened by the National Cancer Institute's Gastrointestinal Cancer Steering Committee to identify the key knowledge gaps in HCC and define clinical research priorities. The CTPM structured its review according to current evidence-based treatment modalities in HCC and prioritized the recommendations on the basis of the patient populations representing the greatest unmet medical need.

[Targeted therapies in hepatocellular carcinoma]

Hepatocellular carcinoma (HCC) stands as a major health problem worldwide. The management of advanced HCC, limited for a longtime by the disappointing results of conventional cytotoxic chemotherapies, has recently changed with the publication of the results of the Sorafenib Hepatocellular Carcinoma Assessment Randomized Protocol (SHARP) trial, which demonstrated an overall survival benefit over placebo in patients with advanced HCC. This study was further confirmed by the Asian-Pacific trial using sorafenib in Eastern patients. Those trials demonstrated that therapeutic benefits may derive from improving our knowledge of deregulated signaling pathways involved in HCC carcinogenesis. This review summarizes the results of clinical trials in which targeted therapies are currently evaluated aiming to enlarge the therapeutic armamentarium for HCC in a near future.

Relationship and prognostic significance of SPARC and VEGF protein expression in colon cancer

Background

SPARC (secreted protein, acidic and rich in cysteine) is closely related with the progress, invasion and metastasis of malignant tumor and angiogenesis.

Methods

Using human colon adenocarcinoma tissues (hereinafter referred to as colon cancer) and their corresponding non-diseased colon from 114 patients' biopsies, the expression of SPARC and vascular endothelial growth factor (VEGF) were investigated by immunohistochemistry staining to assessment the relationship between SPARC and VEGF, as well as their prognostic significance in patients. Evaluation of VEGF expression level with the same tissues was used to establish the antigenic profiles, and the marker of CD34 staining was used as an indicator of microvessel density (MVD).

Results

SPARC expression was mainly in the stromal cells surrounding the colon cancer, and was significant difference in those tissues with the lymph node metastasis and differentiation degree of tumor. Expression of SPARC was significantly correlated with the expression of VEGF and MVD in colon cancer tissues. Patients with low or absence expressing SPARC had significantly worse overall survival and disease-free survival in a Single Factor Analysis; Cox Regression Analysis, SPARC emerged as an overall survival and disease-free survival independent prognostic factor for colon cancer.

Conclusion

The low expression or absence of stromal SPARC was an independent prognostic factor for poor prognosis of colon cancer. SPARC maybe involved in the regulation of anti-angiogenesis by which it may serve as a novel target for colon cancer treatment as well as a novel distinctive marker.

Personalized molecular targeted therapy in advanced, recurrent hepatocellular carcinoma after liver transplantation: a proof of principle

BACKGROUND & AIMS

The advent of molecular medicine that targets specific pathways is changing the therapeutic approach to hepatocellular carcinoma. For several aberrantly activated pathways in hepatocarcinoma, surrogate markers of activation can be assessed by immunohistochemistry, although associations with in vivo response to targeted therapies are still lacking.

METHODS

A patient, who presented with hepatic and extra-hepatic hepatocarcinoma recurrence 11 years after liver transplantation, was assessed for beta-catenin, pERK, and pS6 in primary and secondary tumor specimens, in order to define a possible activation of the Wnt, Ras/MAPK and Akt/mTOR pathways and design a personalized targeted therapy in absence of alternative treatment options. Moreover, mutation analysis of the beta-catenin gene (CTNNB1) and DNA microsatellite analyses were performed.

RESULTS

The identification of the same mutation in the beta-catenin gene, as well as the same microsatellite pattern in tumor tissues taken 11 years apart, proved that the observed hepatocarcinoma was a true recurrence. Nuclear beta-catenin and pS6 in tumor cells were positive, whereas pERK was positive only in the peritumoral endothelium. This pattern of immunohistochemistry, after failure of sorafenib alone, lead to the choice to add the mTOR inhibitor, everolimus, to sorafenib. Three months later a 50% tumor reduction was observed, and after 6 months a further reduction of tumor vital components was confirmed, while a grade II gastrointestinal bleeding episode occurred.

CONCLUSIONS

A personalized approach aimed to treat recurrent hepatocarcinoma is possible through analysis of tumoral molecular pathways. Partial success of the selected combination of sorafenib and everolimus supports the pivotal role of mTOR signalling and highlights the importance of reliable biomarkers to route the best molecular-based therapeutic options in HCC.

Systemic treatment of hepatocellular carcinoma: dawn of a new era?

PURPOSE AND DESIGN

Despite decades of efforts by many investigators, systemic chemotherapy or hormone therapy have failed to demonstrate improved survival in patients with advanced hepatocellular carcinoma (HCC). On the basis of placebo-controlled, randomized phase III trials, sorafenib has shown improved survival benefits in advanced HCC and has set a new standard for future clinical trials. The successful clinical development of sorafenib in HCC has ushered in the era of molecularly targeted agents in this disease, which is discussed in this educational review.

RESULTS AND CONCLUSION

Ongoing studies are evaluating the efficacy and tolerability of combining sorafenib with erlotinib and other targeted agents or chemotherapy. Many molecularly targeted agents that inhibit angiogenesis, epidermal growth factor receptor, and mammalian target of rapamycin are at different stages of clinical development in advanced HCC. Combining targeted agents that inhibit different pathways in hepatocarcinogenesis is an area of active investigation. Future research should continue to unravel the mechanism of hepatocarcinogenesis and to identify key relevant molecular targets for therapeutic intervention. Identification and validation of potential surrogate and predictive biomarkers holds promise to individualize patients' treatment to maximize clinical benefit and minimize the toxicity and cost of targeted agents. We hope that we will continue to improve the efficacy of systemic therapy in advanced HCC in the coming years.

Molecularly targeted therapy in hepatocellular carcinoma

With an annual incidence of over 660,000 deaths, hepatocellular carcinoma (HCC) is the third leading cause of cancer death globally. This disease is often diagnosed at an advanced stage, when potentially curative therapies are not feasible. HCC is highly resistant to conventional systemic therapies and prognosis for advanced HCC patients remains poor. Given the clear need, clinical development of novel therapeutic agents in HCC has begun in earnest. Our recent knowledge of the molecular mechanisms responsible of tumor initiation and progression has identified several potential molecular targets in HCC. These targets are the receptor tyrosine kinase-activated pathways, which include the Raf/MEK/ERK, PI-3K/Akt/mTOR, and Jak/Stat. Sorafenib is the multikinase inhibitor that has shown modest survival benefits in advanced HCC in two randomized controlled trials, supporting the use of molecularly targeted therapies in treatment of HCC. A number of strategies including monoclonal antibodies and tyrosine kinase inhibitors such as erlotinib, sunitinib, vandetanib, cediranib, brivanib, foretinib, and dovitinib have been developed and tested in various phases of clinical trials. The successful development of these novel targeted agents in the future will be dependent on the selection of patient populations that are most likely to derive clinical benefit, optimization of the dose used and schedules, and investigation of combined therapies. This review describes evolving molecular targeted agents, their common adverse side effects, and its potential use in management of HCC.

AZD6244 (ARRY-142886) enhances the antitumor activity of rapamycin in mouse models of human hepatocellular carcinoma

BACKGROUND

The protein kinase B (AKT)/mammalian target of rapamycin (AKT/mTOR) and mitogen activated protein kinase/extracellular regulated kinase kinase/extracellular regulated kinase (MEK/ERK) signaling pathways have been shown to play an important role in hepatocellular carcinoma (HCC) growth and angiogenesis, suggesting that inhibition of these pathways may have therapeutic potential.

METHODS

We treated patient-derived HCC xenografts with 1) mTOR inhibitor rapamycin (RAPA); 2) MEK inhibitor AZD6244 (ARRY-142886); and 3) AZD6244 plus RAPA (AZD6244/RAPA). Western blotting was used to determine pharmacodynamic changes in biomarkers relevant to angiogenesis, mTOR pathway, and MEK signaling. Apoptosis, microvessel density, and cell proliferation were analyzed by immunohistochemistry.

RESULTS

We report here that pharmacological inhibition of the MEK/ERK pathway by AZD6244 enhanced the antitumor and antiangiogenic activities of mTOR inhibitor RAPA in both orthotopic and ectopic models of HCC. Such inhibition led to increased apoptosis, decreased angiogenesis and cell proliferation, reduced expression of positive cell cycle regulators, and increase in proapoptotic protein Bim.

CONCLUSIONS

Our findings indicate that the AZD6244/RAPA combination had antitumor and antiangiogenic effects in preclinical models of human HCC. Given the urgent need for effective therapies in HCC, clinical evaluating AZD6244/RAPA combination seems warranted.