Feng Jiang, MD, PhD

1. Defining molecular genetics and genomic profiling and instabilities of tumors. I pursued projects to analyze cancer genetics using high-throughput comparative genomic technique. My research resulted in articles published in high impact journal, in which I have delineated genomic profiling and instabilities in human solid tumors (Cancer Res, 1999, Am J Pathol, 1998., J Pathol. 1998, and Cancer Res. 1997). Impact: these results provide starting points to identify oncogenes and tumor suppressor genes whose dysregulations promote the development and progression of the tumors, and lay the basis for understanding of the biological basis of tumorigenesis, prevention, and diagnosis of tumors.

2. Constructing oncogenic evolutionary tree models. Carcinogenesis is characterized by an accumulation of complex chromosomal alterations during tumor progression. The nature of subsequent events, their interrelationships, and their sequence is poorly understood. I developed a means to analyze and model cancer development processes based on a more dynamic model, including the presence of multiple pathways, as compared with the fixed linear model. The tree modeling of genomic analysis could advance our understanding the interrelationships of genetic changes in cancer and their possible order, as well as a clustering of these events (A J Com Biol, 1999, Cancer Res. 2000, J. Com Biol. 2000). Impact: using the tree model, one can have in-depth understanding of cancer development process than by simply focusing on the frequencies of genetic events in a given tumor type.

3. Identifying oncogenes by using functional genomic approach. Upregulation of oncogenes confer growth advantages for tumor development. We used a functional genomic approach that integrated simultaneous genomic and transcript microarray, proteomics, and tissue microarray analyses to directly identify putative oncogenes in cancer (Neoplasia, 2004, Oncogene, 2005, Oncogene, 2006, Cancer Res, 2007). For instance, EEF1A2 was identified as a putative oncogene in lung tumorigenesis. Impact: the identified oncogenes provide potential targets for lung cancer diagnosis and therapy.

4. Isolation of tumor initiating cells (TICs) or cancer stem cells (CSCs) of a variety of solid tumors, including lung, prostate, and bladder cancers. Using Aldefluor assay followed by fluorescence-activated cell sorting analysis. We isolated lung cancer cells with high aldehyde dehydrogenase 1 (ALDH1) activity. The ALDH1 positive cells display in vitro features of CSCs, including capacities for proliferation, self-renewal, and differentiation, resistance to chemotherapy, and expressing CSC surface marker CD133. The ALDH1-positive cells generate tumors that recapitulate the heterogeneity of the parental cancer cells. Analysis of clinical specimens from lung cancer patients show that expression of ALDH1 is related to a poor prognosis of the patients. ALDH1 is, therefore, a tumor stem cell-associated marker. We further extend the findings in bladder and prostate cancers (Mol Cancer Res. 2009, Cancer Epidemiol Biomarkers Prev. 2010, and Lab Invest. 2010). Impact: our group was the first to find that ALDH1 could be a marker for cancer stem cells of lung, bladder, and prostate cancers, and might be useful for cancer diagnosis and treatment, and predicting outcomes of the patients with the malignancies. 

5. Characterizing small nucleolar RNAs (snoRNAs) as oncogenes in tumorigenesis. We found that genomic amplification and associated high expression of SNORA42 are frequently observed in lung cancer cells, suggesting that SNORA42 overexpression is activated by its genomic amplification. SNORA42 knock-down in cancer cells inhibits in vitro and in vivo tumorigeneity, whereas enforced SNORA42 expression in normal bronchial epitheliums increases cell viability, proliferation, and colony formation. Such pleiotropy of SNORA42 suppression is achieved through increased apoptosis of NSCLC cells in a p53-dependent manner. SNORA42 expression in lung tumor tissue specimens is correlated with relapse of NSCLCs and a survival of NSCLC patients (Mol Cancer. 2010; Oncogene, 2011; Biochim Biophys Acta 2012). Impact: snoRNAs have long been believed to modify, mature, and stabilize rRNAs for the production of ribosomes. Our study for the first time to demonstrate that snoRNAs have novel function that is: plays an oncogenic role in tumorigenesis. The findings will help understand the regulation and interaction of histone modifications and non-coding RNAs (snoRNAs) in carcinogenesis.

6. Integrating the molecular assay with CT improves lung cancer early detection and diagnosis. To translate the identified cancer-related genetic abnormalities as diagnostic biomarkers, we first developed an in situ genomic mini-chip consisting of multiple quantum dot-labeled probes to detect a panel of genetic aberrations directly on the clinical specimens (Lab Invest. 2005, J. Nanoscience. 2006,). Using the technique, we have measured genetic abnormalities in clinical specimens and found that the changes could be useful in diagnosis of lung cancer, bladder cancer, and lymphomas (Clin Cancer Res. 2007, Cancer 2008, Clinic Cancer Res. 2005, Int J Cancer, 2005, Mod. Pathol. 2004, Cancer, 2004, Diagn Mol Pathol. 2003, J Natl Cancer Inst, 2004). We further evaluated efficacy of combing CT and genetic analysis of sputum for noninvasive diagnosis of stage I lung cancer. A panel of lung cancer-related genes, HYAL2, FHIT, p16, and SP-A was analyzed in sputum from 33 patients with stage I lung cancer and 49 cancer-free controls. Combined approach yielded higher sensitivity, specificity, and accuracy for diagnosing central cancers compared with CT alone (Lung Cancer. 2009).

Making a definitive preoperative diagnosis of solitary pulmonary nodules (SPNs) found by CT has been a clinical challenge. To investigate whether plasma microRNAs are useful in identifying lung cancer among individuals with CT-detected SPNs, we first determined plasma expressions of miRNAs in a training set of patients with malignant SPNs, subjects with benign SPNs to define a panel of miRNAs that has high diagnostic efficiency for lung cancer. We then validate the miRNA panel in a testing set of patients with malignant SPNs and patients with benign SPNs. We identified miR-21, miR-210, and miR-486-5p, which used in combination produced 75.00% sensitivity and 84.95% specificity. The validation of the miRNA panel in the testing set confirms their diagnostic value that yields significant improvement over any single one (BMC Cancer, 2011). impact: the studies lay the solid foundation for further validating the combination of the imaging technique and biomarkers in clinical trials for lung cancer early detection.

7. Developing non-coding RNA (ncRNA) as biomarkers for the early detection of lung cancer. To investigate if ncRNAs can be used as biomarkers for improving lung cancer early detection, we first developed an enrichment technique that can efficiently collect deep respiratory epitheliums from induced sputum (Cancer, 2008). We then identified ncRNA signatures of early stage lung cancer, including 11 small nucleolar RNAs (snoRNAs) and 26 miRNAs (Molecular Cancer, 2010). We demonstrated that miRNAs are useful in lung cancer diagnosis (Lung Cancer, 2009; Modern Pathology, 2010; Int J Cancer, 2010). We also developed panels of sputum-based genomic biomarkers for diagnosis of NSCLC with higher sensitivity compared with sputum cytology (Clinical Cancer Res, 2007; Cancer Res Prevention, 2010). Impact: the findings set up the solid foundation for the development of ncRNA based-biomarkers that can be used to improve lung cancer early detection.

8. Quantifying micorRNAs in plasma and sputum by digital PCR for cancer diagnosis. Analysis of miRNAs by quantitative PCR (qPCR) provides a potential approach for cancer diagnosis. However, absolutely quantifying low abundant miRNAs in clinical specimens is challenging with qPCR. Digital PCR offers a unique means for assessment of nuclei acids presenting at low levels in plasma. To evaluate the efficacy of digital PCR for quantification of miRNAs and the potential of using the technique for cancer diagnosis, we first investigated the efficacy of using digital PCR for quantitative detection of two miRNAs (miRs-21-5p and 335-3p) in artificially seeded samples, RNA of cancer cells, and clinical plasma samples. miRs-21-5p and 335-3p were chosen, because our previous studies showed that miR-21-5p displayed a high expression level, whereas miR-335-3p had an endogenously low level in plasma. We then used digital PCR to quantify copy number of plasma and sputum miR-21-5p and miR-335-3p in 36 lung cancer patients and 38 controls. (Biomarker insights. 2013; J Cancer Res Clin Oncol. 2014). Impact: the studies for the first time present the earliest assessment of digital PCR as a potential tool for quantitative detection of miRNAs in clinical samples for cancer diagnosis.

9. Actively working in a multidisciplinary team that combines complementary expertise in molecular genetics, pathology, medicine, radiology, oncology, surgery, and biostatistics. By closely working with physicians, surgeons, radiologists, and oncologists, and as a PI of an institutional review board approved protocols, I have collected clinical specimens from cancer patients and control populations from multiple medical centers, including University of Maryland Medical Center and Baltimore VA Medical Center.  The specimens with the associated clinical diagnostic information provide unique resources to carry out translational cancer research projects. Impact: My joint effort with other investigators in publications and grants could speak volumes for my collaborative nature and leading an integrative and multidisciplinary research team that is essential to move forward translational lung cancer projects.

10. Characterization of ncRNA transcriptome in lung cancer by next-generation deep sequencing. Systematically characterizing miRNAs in non-small cell lung cancer (NSCLC) will help develop biomarkers for its diagnosis and subclassification, and identify therapeutic targets for the treatment. We used next-generation deep sequencing to comprehensively characterize miRNA profiles in eight lung tumor tissues consisting of two major types of NSCLC, squamous cell carcinoma (SCC) and adenocarcinoma (AC). We used qPCR to verify the findings in 40 pairs of stage I NSCLC and normal tissues, and 60 NSCLC tissues of different types and stages. We also investigated the function of identified miRNAs in lung tumorigenesis.  Deep sequencing identified 896 known miRNAs and 14 novel miRNAs, of which, 24 miRNAs displayed dysregulation with fold change ≥4.5 in either stage I ACs or SCCs or both relative to normal tissues. qPCR validation showed that 14 of 24 miRNAs exhibited consistent changes with deep sequencing data. Seven miRNAs displayed distinctive expressions between SCC and AC, from which, a panel of four miRNAs (miRs-944, 205-3p, 135a-5p, and 577) was identified that cold differentiate SCC from AC with 93.3% sensitivity and 86.7% specificity. Impact: Our results lay the solid basis for further carrying out new projects, in which we will 1), define the functional significance of newly identified miRNAs in cancer development and progression, and exploit this information to identify and validate promising targets. 2), define the miRNA-related pathways that silence tumor suppressor genes in solid cancers.

11. Downregulation of miR-486-5p contributes to tumor progression and metastasis by targeting pro-tumorigenic ARHGAP5 and Pim-1 in lung cancer. We have previously shown that miR-486-5p is one of the most downregulated miRNAs in lung cancer. We evaluated miR-486-5p expression status on 76 frozen and 33 formalin-fixed paraffin-embedded tissues of NSCLC by qRT-PCR to determine its clinicopathologic significance. We then performed function analysis of miR-486-5p to determine its potential roles on cancer cell migration and invasion in vitro and metastasis in vivo. We also investigated the target genes of miR-486-5p in lung tumorigenesis. MiR-486-5p expression level was significantly lower in lung tumors compared with their corresponding normal tissues, and associated with stage and lymph node metastasis of NSCLC. Forced expression of miR-486-5p inhibited NSCLC cell migration and invasion in vitro and metastasis in mice by inhibiting cell proliferation. Furthermore, ectopic expression of miR-486-5p in cancer cells reduced ARHGAP5 and Pim-1 expression levels, whereas miR-486-5p silencing increased their expression. Luciferase assay demonstrated that miR-486-5p could directly bind to the 3′ untranslated region of ARHGAP5 and Pim-1. The expression level of miR-486-5p was inversely correlated with that of ARHGAP5 and Pim-1 in lung tumor tissues. Reduced expression of ARHGAP5 and Pim-1 considerably inhibited lung cancer cell migration and invasion, resembling that of miR-486-5p overexpression (Wang, et al, 2013, Shen, et al, 2013). Impact: MiR-486-5p may act as a tumor suppressor contributing to the progression and metastasis of NSCLC by targeting ARHGAP5 and Pim-1. MiR-486-5p would provide potential diagnostic and therapeutic targets for the disease.

12. Sputum microRNA biomarkers for identifying lung cancer in indeterminate solitary pulmonary nodules. The early detection of lung cancer in heavy smokers by low-dose CT (LDCT) can reduce the mortality. However, LDCT produces a substantial number of indeterminate solitary pulmonary nodules (SPNs), leading to a high level of overdiagnosis. Having a definitive preoperative diagnosis of malignant SPNs is a clinical challenge. Using a training set of cases and controls, we developed a panel of three miRNA biomarkers (miRs-21, 31, and 210) that could diagnose early stage lung cancer among SPNs with 82.93% sensitivity and 87.84% specificity. We then confirmed the diagnostic performance of the biomarkers in two independent testing cohorts (Xing, et al, 2015). Impact: sputum miRNA biomarkers may have potential utility in risk-stratifying indeterminate SPNs, and improving LDCT screening for lung cancer in heavy smokers.