Role of Systemic Therapy and Future Directions for Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is an aggressive tumor that often arises in the setting of liver cirrhosis. Although early-stage disease is often amenable for surgical resection, transplant, or locoregional therapies, many patients are diagnosed at an advanced stage or have poor liver reserve. Systemic therapy is the mainstay of treatment for these patients. At present, the only approved therapy for the treatment of advanced disease is the tyrosine multikinase inhibitor sorafenib. Candidacy for treatment is based on liver reserve. Novel agents for the treatment of this disease are urgently needed. In this article, we review systemic therapy trials and upcoming data for the treatment of HCC.

New insights in the treatment of radioiodine refractory differentiated thyroid carcinomas: to lenvatinib and beyond.

During the past two decades, several key somatic mutations associated with development and progression of differentiated thyroid cancer (DTC) have been revealed. Historically, the treatment for advanced DTC is challenging after patients become refractory to radioactive iodine. The response to doxorubicin, the only chemotherapy agent approved by the US Food and Drug Administration, is disappointing either as monotherapy or combination therapy. Because of the lack of effective systemic treatment coupled with increased understanding of molecular and cellular pathogenesis, multiple kinase inhibitors (MKIs) as an alternative therapy for the treatment of advanced DTC has generated much interest, enthusiasm, and, most excitingly, promising results. After the encouraging results of these agents in earlier trials, the Food and Drug Administration approved sorafenib for the treatment of locally recurrent, progressive, or metastatic DTC refractory to radioactive iodine treatment based on the results of a multicenter DECISION trial. Sorafenib therefore became the first MKI approved for this indication in more than 20 years. However, even more impressive responses and progression-free survival benefits were seen in the phase III SELECT trial with lenvatinib, giving even higher hopes for the future management of what was considered just a decade ago an orphan disease. Given the role of MKIs, a new era in the treatment of advanced DTC has begun. We review the key therapeutic targets, oncogenic pathways, and promising clinical results of these agents in refractory disease, as well as their roles after failure of first line kinase inhibitors.

Programmed death-1 (PD-1)-deficient mice are extraordinarily sensitive to tuberculosis.

The programmed death-1 (PD-1) costimulatory receptor inhibits T and B cell responses and plays a crucial role in peripheral tolerance. PD-1 has recently been shown to inhibit T cell responses during chronic viral infections such as HIV. In this study, we examined the role of PD-1 in infection with Mycobacterium tuberculosis, a common co-infection with HIV. PD-1-deficient mice showed dramatically reduced survival compared with wild-type mice. The lungs of the PD-1-/- mice showed uncontrolled bacterial proliferation and focal necrotic areas with predominantly neutrophilic infiltrates, but a lower number of infiltrating T and B cells. Proinflammatory cytokines, such as TNF-alpha, IL-1, and especially IL-6 and IL-17 were significantly increased in the lung and sera of infected PD-1-/- mice, consistent with an aberrant inflammation. Microarray analysis of the lungs infected with M. tuberculosis showed dramatic differences between PD-1-/- and control mice. Using high-stringency analysis criteria (changes of twofold or greater), 367 transcripts of genes were differentially expressed between infected PD-1-/- and wild-type mice, resulting in profoundly altered inflammatory responses with implications for both innate and adaptive immunity. Overall, our studies show that the PD-1 pathway is required to control excessive inflammatory responses after M. tuberculosis infection in the lungs.

Prognostic value of CD8CD45RO tumor infiltrating lymphocytes in patients with extrahepatic cholangiocarcinoma.

Cholangiocarcinoma is a malignancy arising from the biliary tract epithelial cells with poor prognosis. Tumor infiltrating lymphocytes (TIL)s and programmed cell death receptor ligand 1 (PD-L1) have a prognostic impact in various solid tumors. We aimed to investigate TILs and PD-L1 expression and their clinical relevance in cholangiocarcinoma. Tumor samples from 44 patients with resected and histologically verified extrahepatic cholangiocarcinoma were evaluated for CD8, CD45RO and PD-L1 expression, and their correlations with clinicopathological data and survival data were analyzed. Total 44 extrahepatic cholangiocarcinoma tissues were evaluated. CD8+ tumor infiltrating lymphocytes (TIL)s were observed in 30 (68%) tumors. Among them, 14 had CD8+CD45RO+ TILs. PD-L1 was expressed on cancer cells in 10 (22.7%) tumors in 34 evaluable extrahepatic cholangiocarciniomas. The presence of CD8+ TILs or CD8+CD45RO+ TILs was not associated with clinical staging or tumor differentiation. Extrahepatic cholangiocarcinoma with CD8+CD45RO+ TILs had longer overall survival (OS) on univariate (P = 0.013) and multivariate (P = 0.012) analysis. Neither CD8+TIL nor PD-L1 expression on cancer cells correlated significantly with OS. These results add to the understanding of the clinical features associated with CD8 TILs and PD-L1 expression in extrahepatic cholangiocarcinoma, and they support the potential rationale of using PD-1 blockade immunotherapy in cholangiocarcinoma.

Cell-free circulating tumor DNA supplementing tissue biopsies for identification of targetable mutations: Implications for precision medicine and considerations for reconciling results.

Cell-free circulating tumor DNA (ctDNA) next-generation sequencing (NGS) is emerging as a noninvasive technique for detecting targetable mutations. We describe two lung adenocarcinoma cases that show the clinical utility of supplementing tumor biopsy molecular interrogation with ctDNA NGS. For both cases, ctDNA NGS identified actionable mutations that were previously not reported by molecular interrogation of tissue. Explanations are provided for the observed differences between ctDNA and tumor biopsy genomic results along with considerations for reconciling findings. Case 1 consisted of a patient with multiple lesions in the left and right lung that was initially suspected to be related to malignancy. A tumor biopsy was positive for EGFR-mutated lung cancer. ctDNA NGS reported an activating KRAS mutation, which was unexpected given the rare occurrence of EGFR/KRAS co-mutations. Radiologic imaging and ctDNA NGS resulted in the diagnoses of synchronous EGFR-mutated left lung cancer and KRAS-mutated right lung cancer. The second case describes a patient who was negative for RET rearrangements by tissue interrogation, but positive for a RET-KIF5B fusion by ctDNA NGS. Further tissue analysis demonstrated heterogeneity was the cause of differing results. We demonstrate that supplementing tumor biopsies with ctDNA NGS has a crucial role in patient care. Understanding the causes of differing ctDNA and tumor biopsy genomic results is essential for reconciling findings and application to precision medicine management.

Microglia from mice transgenic for a provirus encoding a monocyte-tropic HIV type 1 isolate produce infectious virus and display in vitro and in vivo upregulation of lipopolysaccharide-induced chemokine gene expression.

A large body of evidence has indicated that microglia are the predominant cellular location for HIV-1 in the brains of HIV-1-infected individuals and play a direct role in the development of HIV-1-associated dementia (HAD). Therefore, investigation of the mechanism by which HIV-1-infected microglia contribute to the development of HIV-associated dementia should be facilitated by the creation of a mouse model wherein microglia carry replication-competent HIV-1. To circumvent the inability of HIV-1 to infect mouse cells, we developed a mouse line that is transgenic for a full-length proviral clone of a monocyte-tropic HIV-1 isolate, HIV-1(JR-CSF) (JR-CSF mice), whose T cells and monocytes produce infectious HIV-1. We detected expression of the long terminal repeat-regulated proviral transgene in the microglia of these transgenic mice and demonstrated that it was increased by in vitro and in vivo stimulation with lipopolysaccharide. Furthermore, microglia isolated from JR-CSF mouse brains produced HIV-1 that was infectious in vitro and in vivo. We examined the effect that carriage of the HIV-1 provirus had on chemokine gene regulation in the brains of these mice and demonstrated that MCP-1 gene expression by JR-CSF mouse microglia and brains was more responsive to in vitro and in vivo stimulation with lipopolysaccharide than were microglia and brains from control mice. Thus, this study indicates that the JR-CSF mice may represent a new mouse model to study the effect of HIV-1 replication on microglia function and its contribution to HIV-1-associated neurological disease.

Biologic impact and clinical implication of mTOR inhibition in metastatic breast cancer.

ABSTRACTThe goal of therapy for patients with metastatic breast cancer (MBC) is prolonging life and palliation of symptoms. Thus the preferred approach remains to use, at least initially, non-cytotoxic drugs. In hormone receptor-positive breast cancer the sequential use of single anti-estrogen drugs, e.g. tamoxifen, aromatase inhibitors, and many others is standard, but eventually drug resistance will lead to failure of these compounds and a switch to chemotherapy will be necessary. Reversing resistance to anti-estrogen therapy in MBC is one of the strategies to avoid and delay the use of cytotoxic compounds. The mammalian target of rapamycin (mTOR) has been recently associated with in vitro reversal of drug resistance, including tamoxifen resistance. A number of early clinical studies have confirmed the concept and, more recently, everolimus was successfully tested in a randomized controlled trial in postmenopausal patients who progressed on previous anti-estrogen therapy for MBC. This manuscript will review the biology, preclinical and clinical data including the randomized controlled trial that lead to the approval of everolimus by the US FDA.

Is the Improved Efficacy of Trastuzumab and Lapatinib Combination Worth the Added Toxicity? A Discussion of Current Evidence, Recommendations, and Ethical Issues Regarding Dual HER2-Targeted Therapy.

Following FDA approval of trastuzumab in 1998 and lapatinib in 2007, several clinical studies have addressed the question of whether trastuzumab and lapatinib combination therapy is better than trastuzumab alone in the metastatic breast cancer and neoadjuvant setting. In this review, updated to September 2012, we focus on the relevant clinical trials that address this question and, based on the available data, reach conclusions regarding a rational and reasonably individualized approach to the management of HER2+ breast cancer. With the FDA approval of pertuzumab in June 2012 and the likely approval of T-DM1 approaching, several ethical issues overshadow the excitement oncologists have for these new treatment options. We discuss the potential evolution of highly active anti-HER2 therapy (HAAHT) as an optimal treatment paradigm for HER2+ breast cancer. Additionally, we review lessons learned from the evolution of HAART for HIV treatment.

Lack of essential role of NF-kappa B p50, RelA, and cRel subunits in virus-induced type 1 IFN expression.

Type 1 IFNs (IFN-alphabeta) play pivotal roles in the host antiviral response and in TLR-induced signaling. IFN regulatory factor (IRF) and NF-kappaB transcription factors are thought to be crucial for virus-induced mRNA expression of IFN-beta. Although recent studies have demonstrated essential roles for IRF3 and IRF7, the definitive role of NF-kappaB factors in IFN-beta (or IFN-alpha) expression remains unknown. Using mice deficient in distinct members of the NF-kappaB family, we investigated NF-kappaB function in regulating type 1 IFN expression in response to Sendai virus and Newcastle disease virus infection. Surprisingly, IFN-beta and IFN-alpha expression was strongly induced following virus infection of mouse embryonic fibroblasts (MEFs) from p50(-/-), RelA/p65(-/-), cRel(-/-), p50(-/-)cRel(-/-), and p50(-/-)RelA(-/-) mice. Compared with wild-type MEFs, only RelA(-/-) and p50(-/-)RelA(-/-) MEFs showed a modest reduction in IFN-beta expression. To overcome functional redundancy between different NF-kappaB subunits, we expressed a dominant-negative IkappaBalpha protein in p50(-/-)RelA(-/-) MEFs to inhibit activation of remaining NF-kappaB subunits. Although viral infection of these cells failed to induce detectable NF-kappaB activity, both Sendai virus and Newcastle disease virus infection led to robust IFN-beta expression. Virus infection of dendritic cells or TLR9-ligand CpG-D19 treatment of plasmacytoid dendritic cells from RelA(-/-) or p50(-/-)cRel(-/-) mice also induced robust type 1 IFN expression. Our findings therefore indicate that NF-kappaB subunits p50, RelA, and cRel play a relatively minor role in virus-induced type 1 IFN expression.

Specificity of interaction of INI1/hSNF5 with retroviral integrases and its functional significance.

Integrase interactor 1 (INI1)/hSNF5 is a host factor that directly interacts with human immunodeficiency virus type 1 (HIV-1) integrase and is incorporated into HIV-1 virions. Here, we show that while INI1/hSNF5 is completely absent from purified microvesicular fractions, it is specifically incorporated into HIV-1 virions with an integrase-to-INI1/hSNF5 stoichiometry of approximately 2:1 (molar ratio). In addition, we show that INI1/hSNF5 is not incorporated into related primate lentiviral and murine retroviral particles despite the abundance of the protein in producer cells. We have found that the specificity in incorporation of INI1/hSNF5 into HIV-1 virions is directly correlated with its ability to exclusively interact with HIV-1 integrase but not with other retroviral integrases. This specificity is also reflected in our finding that the transdominant mutant S6, harboring the minimal integrase interaction domain of INI1/hSNF5, blocks HIV-1 particle production but not that of the other retroviruses in 293T cells. Taken together, these results suggest that INI1/hNSF5 is a host factor restricted for HIV-1 and that S6 acts as a highly specific and potent inhibitor of HIV-1 replication.

Development of a novel transgenic mouse/SCID-hu mouse system to characterize the in vivo behavior of reservoirs of human immunodeficiency virus type 1-infected cells.

To develop a system in which transgenic and knockout technologies are used to study the in vivo behavior of human immunodeficiency virus type 1 (HIV-1) reservoirs, 2 different mouse models were combined: transgenic mice carrying full-length provirus encoding the monocyte-tropic HIV-1(JR-CSF) isolate (JR-CSF mice) and severe combined immunodeficient mice implanted with human fetal thymus and liver tissues (thy/liv-SCID-hu mice). Extensive HIV-1 infection of human thymic implants occurred after injection of JR-CSF mouse leukocytes into thy/liv-SCID-hu mice, indicating that these cells provide an in vivo source of replication-competent HIV-1. In vivo persistence of transferred JR-CSF mouse leukocytes carrying replication-competent HIV-1 in thy/liv-SCID-hu mice was indicated by the emergence of HIV-1 infection in mice that had no detectable HIV-1 infection until after highly active antiretroviral therapy. Thus, thy/liv-SCID-hu mice populated with JR-CSF mouse leukocytes, a persistent cellular reservoir harboring replication-competent HIV-1, present a new in vivo system for characterizing reservoirs of HIV-1 and evaluating therapeutic strategies designed to eliminate them.