Wen-Lang Fan

The urokinase-type plasminogen activator (uPA) system as a biomarker and therapeutic target in human malignancies

ABSTRACT Introduction: The urokinase plasminogen activator (uPA) system, comprising the serine protease uPA, its cognate receptor, uPAR, and two endogenous inhibitors, plasminogen activator inhibitor-1 (PAI-1) and plasminogen activator inhibitor-2 (PAI-2), is a key player in the break-down of extracellular matrix (ECM) and basement membrane. Elevated expression of uPA and uPAR is observed in numerous cancer types and associated with poor prognosis. Areas covered: In addition to the aberrant expression during tumor development, the components of uPA system are functionally involved in various processes that are prerequisite for cancer progression. These processes include, but not limited to, ECM degradation, angiogenesis, cell proliferation, adhesion, migration and epithelial–mesenchymal transition. All of these findings implicate uPA system as a target for cancer treatment. Thus, therapeutic agents and approaches to targeting the constituents of uPA system, mainly at their expression level and biological activities, have been extensively used in antineoplastic investigations. Expert opinion: Because of promising results obtained from previous preclinical studies, several clinical trials aimed at inhibiting the expression or function of uPA/uPAR have been completed or are ongoing. In these trials, favorable outcomes in reducing metastatic spread and extending the lifespan of cancer patients have been reported, and no severe adverse events were observed.

Exome Sequencing of Oral Squamous Cell Carcinoma Reveals Molecular Subgroups and Novel Therapeutic Opportunities

Oral squamous cell carcinoma (OSCC), an epithelial malignancy affecting a variety of subsites in the oral cavity, is prevalent in Asia. The survival rate of OSCC patients has not improved over the past decades due to its heterogeneous etiology, genetic aberrations, and treatment outcomes. Improvement in therapeutic strategies and tailored treatment options is an unmet need. To unveil the mutational spectrum, whole-exome sequencing of 120 OSCC from male individuals in Taiwan was conducted. Analyzing the contributions of the five mutational signatures extracted from the dataset of somatic variations identified four groups of tumors that were significantly associated with demographic and clinical features. In addition, known (TP53, FAT1, EPHA2, CDKN2A, NOTCH1, CASP8, HRAS, RASA1, and PIK3CA) and novel (CHUK and ELAVL1) genes that were significantly and frequently mutated in OSCC were discovered. Further analyses of gene alteration status with clinical parameters revealed that the tumors of the tongue were enriched with copy-number alterations in several gene clusters containing CCND1 and MAP4K2. Through defining the catalog of targetable genomic alterations, 58% of the tumors were found to carry at least one aberrant event potentially targeted by US Food and Drug Administration (FDA)-approved agents. Strikingly, if targeting the p53-cell cycle pathway (TP53 and CCND1) by the drugs studied in phase I-III clinical trials, those possibly actionable tumors are predominantly located in the tongue, suggesting a better prediction of sensitivity to current targeted therapies. Our work revealed molecular OSCC subgroups that reflect etiological and prognostic correlation as well as defined the landscape of major altered events in the coding regions of OSCC genomes. These findings provide clues for the design of clinical trials for targeted therapies and stratification of OSCC patients with differential therapeutic efficacy.

Severe Cutaneous Adverse Reactions: The Pharmacogenomics from Research to Clinical Implementation

Severe cutaneous adverse reactions (SCARs), previously thought to be idiosyncratic or unpredictable, are a deadly form of adverse drug reactions with skin manifestations. Current pharmacogenomic studies of SCARs have made important strides, as the prevention of SCARs, to some extent, appears attainable with the identification of genetic variants for genes encoding drug-metabolizing enzymes and human leukocyte antigens (HLAs). Despite the improvement of incidence, a treatment guideline for this devastating condition is still unavailable, highlighting the inadequacy of contemporary accepted therapeutic interventions. As such, prompt withdrawal of causative drugs is believed to be a priority of patient management. In this review, we discuss recent cutting-edge findings concerning the discovery of biomarkers for SCARs and their clinical utilities in the better prediction and early diagnosis of this disease. The knowledge compiled herein provides clues for future investigations on deciphering additional genetic markers for SCARs and the design of clinical trials for the prospective identification of subjects at genetic risk for this condition, ultimately personalizing the medicine.

Randomized, controlled trial of TNF-α antagonist in CTL-mediated severe cutaneous adverse reactions

BACKGROUND. Cytotoxic T lymphocyte–mediated (CTL-mediated) severe cutaneous adverse reactions (SCARs), including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), are rare but life-threatening adverse reactions commonly induced by drugs. Although high levels of CTL-associated cytokines, chemokines, or cytotoxic proteins, including TNF-&agr; and granulysin, were observed in SJS-TEN patients in recent studies, the optimal treatment for these diseases remains controversial. We aimed to evaluate the efficacy, safety, and therapeutic mechanism of a TNF-&agr; antagonist in CTL-mediated SCARs. METHODS. We enrolled 96 patients with SJS-TEN in a randomized trial to compare the effects of the TNF-&agr; antagonist etanercept versus traditional corticosteroids. RESULTS. Etanercept improved clinical outcomes in patients with SJS-TEN. Etanercept decreased the SCORTEN-based predicted mortality rate (predicted and observed rates, 17.7% and 8.3%, respectively). Compared with corticosteroids, etanercept further reduced the skin-healing time in moderate-to-severe SJS-TEN patients (median time for skin healing was 14 and 19 days for etanercept and corticosteroids, respectively; P = 0.010), with a lower incidence of gastrointestinal hemorrhage in all SJS-TEN patients (2.6% for etanercept and 18.2% for corticosteroids; P = 0.03). In the therapeutic mechanism study, etanercept decreased the TNF-&agr; and granulysin secretions in blister fluids and plasma (45.7%–62.5% decrease after treatment; all P < 0.05) and increased the Treg population (2-fold percentage increase after treatment; P = 0.002), which was related to mortality in severe SJS-TEN. CONCLUSIONS. The anti–TNF-&agr; biologic agent etanercept serves as an effective alternative for the treatment of CTL-mediated SCARs. TRIAL REGISTRATION. ClinicalTrials.gov NCT01276314. FUNDING. Ministry of Science and Technology of Taiwan.

Effects of RAGE Gene Polymorphisms on the Risk and Progression of Hepatocellular Carcinoma

AbstractHepatocellular carcinoma (HCC) is a common malignancy of the liver, whose heterogeneous incidence reflects genetic variations among individuals in the main risk factors. The receptor for advanced glycosylation endproducts (RAGE) is a multiligand receptor and known to be implicated in various pathogenic conditions, such as diabetes, inflammatory disorder, Alzheimer disease, and cancer. In this study, the impact of RAGE gene polymorphisms on the susceptibility to hepatocarcinogenesis was explored. Four single-nucleotide polymorphisms (SNPs), rs184003 (1704G > T), rs1800624 (−374T > A), rs1800625 (−429T > C), and rs2070600 (Gly82Ser), as well as 1 gene polymorphism of RAGE gene, a 63 bp deletion allele (−407 to −345) were analyzed between 300 cancer-free subjects and 265 HCC cases. We detected a significant association of rs1800625 with the increased risk of HCC (odds ratio [OR], 2.565; 95% confidence interval [CI], 1.492–4.409 and adjusted odds ratio [AOR], 2.568; 95% CI, 1.418–4.653). However, patients who possess at least 1 polymorphic allele of rs1800625 are less prone to develop late-stage (stage III/IV, OR, 0.502; 95% CI, 0.243–1.037; P = 0.059 and AOR, 0.461; 95% CI, 0.219–0.970; P = 0.041) and large-size tumors (OR, 0.398; 95% CI, 0.183–0.864; P = 0.017 and AOR, 0.351; 95% CI, 0.157–0.781; P = 0.010). Furthermore, individuals bearing specific haplotypes of 4 RAGE SNPs tested are more inclined to have HCC. In conclusion, our data suggest a correlation of RAGE gene polymorphism rs1800625 with the early stage of liver tumorigenesis and implicate its protective role in the progression of HCC.

Compositional and functional variations of oral microbiota associated with the mutational changes in oral cancer

OBJECTIVES Both genetic and environmental factors are conceivably required to assess the prognosis of oral squamous cell carcinoma (OSCC), yet little is known regarding the relationship between oral microbiome and the mutational spectrum of OSCC. MATERIALS AND METHODS Here, we used 16S rRNA amplicon sequencing to study the composition of oral microorganisms in OSCC patients, whose cancer mutational profiles were previously defined by whole-exome sequencing, to evaluate the relationship between oral microbiome and the mutational changes in OSCC. RESULTS Analyzing the contributions of the five mutational signatures extracted from the primary tumors revealed three groups of OSCC (mutational signature cluster, MSC1-3) that were significantly associated with demographic and clinical features. Taxonomic analysis of the predominant phyla in salivary samples showed variation in the relative abundance of Firmicutes and Bacteroidetes in the three MSC groups. In addition, significant differences in bacterial species richness (alpha diversity) and slight sample-to-sample dissimilarities in bacterial community structures (beta diversity) were noted among different MSC groups. Further, predicting the functional capabilities of microbial communities by reconstruction of unobserved states showed that many pathways related to cell motility were differentially enriched among the three MSC groups. CONCLUSION Collectively, these results indicate a potential association of oral microbiome with the mutational changes in OSCC.

The Medication Risk of Stevens–Johnson Syndrome and Toxic Epidermal Necrolysis in Asians: The Major Drug Causality and Comparison With the US FDA Label

Specific ethnic genetic backgrounds are associated with the risk of Stevens–Johnson syndrome / toxic epidermal necrolysis (SJS/TEN) especially in Asians. However, there have been no large cohort, multiple‐country epidemiological studies of medication risk related to SJS/TEN in Asian populations. Thus, we analyzed the registration databases from multiple Asian countries who were treated during 1998–2017. A total 1,028 SJS/TEN cases were identified with the algorithm of drug causality for epidermal necrolysis. Furthermore, those medications labeled by the US Food and Drug Administration (FDA) as carrying a risk of SJS/TEN were also compared with the common causes of SJS/TEN in Asian countries. Oxcarbazepine, sulfasalazine, COX‐II inhibitors, and strontium ranelate were identified as new potential causes. In addition to sulfa drugs and beta‐lactam antibiotics, quinolones were also a common cause. Only one acetaminophen‐induced SJS was identified, while several medications (e.g., oseltamivir, terbinafine, isotretinoin, and sorafenib) labeled as carrying a risk of SJS/TEN by the FDA were not found to have caused any of the cases in the Asian countries investigated in this study.

HLA Association with Drug-Induced Adverse Reactions

Adverse drug reactions (ADRs) remain a common and major problem in healthcare. Severe cutaneous adverse drug reactions (SCARs), such as Stevens–Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) with mortality rate ranges from 10% to more than 30%, can be life threatening. A number of recent studies demonstrated that ADRs possess strong genetic predisposition. ADRs induced by several drugs have been shown to have significant associations with specific alleles of human leukocyte antigen (HLA) genes. For example, hypersensitivity to abacavir, a drug used for treating of human immunodeficiency virus (HIV) infection, has been proposed to be associated with allele 57:01 of HLA-B gene (terms HLA-B∗57:01). The incidences of abacavir hypersensitivity are much higher in Caucasians compared to other populations due to various allele frequencies in different ethnic populations. The antithyroid drug- (ATDs- ) induced agranulocytosis are strongly associated with two alleles: HLA-B∗38:02 and HLA-DRB1∗08:03. In addition, HLA-B∗15:02 allele was reported to be related to carbamazepine-induced SJS/TEN, and HLA-B∗57:01 in abacavir hypersensitivity and flucloxacillin induced drug-induced liver injury (DILI). In this review, we summarized the alleles of HLA genes which have been proposed to have association with ADRs caused by different drugs.

HLA Alleles and CYP2C9*3 as Predictors of Phenytoin Hypersensitivity in East Asians

To develop a pre‐emptive genetic test that comprises multiple predisposing alleles for the prevention of phenytoin‐related severe cutaneous adverse reactions (SCARs), three sets of patients with phenytoin‐SCAR and drug‐tolerant controls from Taiwan, Thailand, and Japan, were enrolled for this study. In addition to cytochrome P450 (CYP)2C9*3, we found that HLA‐B*13:01, HLA‐B*15:02, and HLA‐B*51:01 were significantly associated with phenytoin hypersensitivity with distinct phenotypic specificities. Strikingly, we showed an increase in predictive sensitivity of concurrently testing CYP2C9*3/HLA‐B*13:01/HLA‐B*15:02/HLA‐B*51:01 from 30.5–71.9% for selecting the individuals with the risk of developing phenytoin‐SCAR in Taiwanese cohorts, accompanied by a specificity of 77.7% (combined sensitivity, 64.7%; specificity, 71.9% for three Asian populations). Meta‐analysis of the four combined risk alleles showed significant associations with phenytoin‐SCAR in three Asian populations. In conclusion, combining the assessment of risk alleles of HLA and CYP2C9 potentiated the usefulness of predictive genetic tests to prevent phenytoin hypersensitivity in Asians.

Whole-Genome Sequencing of a Family with Hereditary Pulmonary Alveolar Proteinosis Identifies a Rare Structural Variant Involving CSF2RA/CRLF2/IL3RA Gene Disruption

Pulmonary alveolar proteinosis (PAP) is a rare pulmonary disease in which the abnormalities in alveolar surfactant accumulation are caused by impairments of GM-CSF pathway attributing to defects in a variety of genes. However, hereditary PAP is extremely uncommon and a detailed understanding in the genetic inheritance of PAP in a family may provide timely diagnosis, treatment and proper intervention including genetic consultation. Here, we described a comprehensive analysis of genome and gene expression for a family containing one affected child with a diagnosis of PAP and two other healthy siblings. Family-based whole-genome analysis revealed a homozygous deletion that disrupts CSF2RA, CRLF2, and IL3RA gene in the pseudoautosomal region of the X chromosome in the affected child and one of asymptomatic siblings. Further functional pathway analysis of differentially expressed genes in IL-1β-treated peripheral blood mononuclear cells highlighted the insufficiency of immune response in the child with PAP, especially the protection against bacterial infection. Collectively, our results reveal a novel allele as the genetic determinant of a family with PAP and provide insights into variable expressivity and incomplete penetrance of this rare disease, which will be helpful for proper genetic consultation and prompt treatment to avoid mortality and morbidity.