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1.  Gene Expression Profile of A549 Cells from Tissue of 4D Model Predicts Poor Prognosis in Lung Cancer Patients 
The tumor microenvironment plays an important role in regulating cell growth and metastasis. Recently, we developed an ex vivo lung cancer model (4D) that forms perfusable tumor nodules on a lung matrix that mimics human lung cancer histopathology and protease secretion pattern. We compared the gene expression profile (Human OneArray v5 chip) of A549 cells, a human lung cancer cell line, grown in a petri dish (2D), and of the same cells grown in the matrix of our ex vivo model (4D). Furthermore, we obtained gene expression data of A549 cells grown in a petri dish (2D) and matrigel (3D) from a previous study and compared the 3D expression profile with that of 4D. Expression array analysis showed 2,954 genes differentially expressed between 2D and 4D. Gene ontology (GO) analysis showed upregulation of several genes associated with extracellular matrix, polarity, and cell fate and development. Moreover, expression array analysis of 2D versus 3D showed 1006 genes that were most differentially expressed, with only 36 genes (4%) having similar expression patterns as observed between 2D and 4D. Finally, the differential gene expression signature of 4D cells (versus 2D) correlated significantly with poor survival in patients with lung cancer (n = 1,492), while the expression signature of 3D versus 2D correlated with better survival in lung cancer patients with lung cancer. Since patients with larger tumors have a worse rate of survival, the ex vivo 4D model may be a good mimic of natural progression of tumor growth in lung cancer patients.
PMCID: PMC4070715  PMID: 23934967
Lung cancer; matrigel; ex vivo 4D model; gene expression profile; survival
2.  Human Lung Cancer Cells Grown on Acellular Rat Lung Matrix Create Perfusable Tumor Nodules 
The Annals of thoracic surgery  2012;93(4):1075-1081.
Extracellular matrix allows lung cancer to form its shape and grow. Recent studies on organ reengineering for orthotopic transplantation have provided a new avenue for isolating purified native matrix to use for growing cells. Whether human lung cancer cells grown in a decellularized rat lung matrix would create perfusable human lung cancer nodules was tested.
Rat lungs were harvested and native cells were removed using sodium dodecyl sulfate and Triton X-100 in a decellularization chamber to create a decellularized rat lung matrix. Human A549, H460, or H1299 lung cancer cells were placed into the decellularized rat lung matrix and grown in a customized bioreactor with perfusion of oxygenated media for 7 to 14 days.
Decellularized rat lung matrix showed preservation of matrix architecture devoid of all rat cells. All three human lung cancer cell lines grown in the bioreactor developed tumor nodules with intact vasculature. Moreover, the lung cancer cells developed a pattern of growth similar to the original human lung cancer.
Overall, this study shows that human lung cancer cells form perfusable tumor nodules in a customized bioreactor on a decellularized rat lung matrix created by a customized decellularization chamber. The lung cancer cells grown in the matrix had features similar to the original human lung cancer. This ex vivo model can be used potentially to gain a deeper understanding of the biologic processes involved in human lung cancer.
PMCID: PMC4512949  PMID: 22385822
3.  Lysyl hydroxylase 2 induces a collagen cross-link switch in tumor stroma 
The Journal of Clinical Investigation  2015;125(3):1147-1162.
Epithelial tumor metastasis is preceded by an accumulation of collagen cross-links that heighten stromal stiffness and stimulate the invasive properties of tumor cells. However, the biochemical nature of collagen cross-links in cancer is still unclear. Here, we postulated that epithelial tumorigenesis is accompanied by changes in the biochemical type of collagen cross-links. Utilizing resected human lung cancer tissues and a p21CIP1/WAF1-deficient, K-rasG12D-expressing murine metastatic lung cancer model, we showed that, relative to normal lung tissues, tumor stroma contains higher levels of hydroxylysine aldehyde–derived collagen cross-links (HLCCs) and lower levels of lysine aldehyde–derived cross-links (LCCs), which are the predominant types of collagen cross-links in skeletal tissues and soft tissues, respectively. Gain- and loss-of-function studies in tumor cells showed that lysyl hydroxylase 2 (LH2), which hydroxylates telopeptidyl lysine residues on collagen, shifted the tumor stroma toward a high-HLCC, low-LCC state, increased tumor stiffness, and enhanced tumor cell invasion and metastasis. Together, our data indicate that LH2 enhances the metastatic properties of tumor cells and functions as a regulatory switch that controls the relative abundance of biochemically distinct types of collagen cross-links in the tumor stroma.
PMCID: PMC4362236  PMID: 25664850
4.  Treatment of Sternoclavicular Joint Osteomyelitis with Debridement and Delayed Resection with Muscle Flap Coverage Improves Outcomes 
Surgery Research and Practice  2014;2014:747315.
The objective of this study was to evaluate the efficacy of various treatment options for sternoclavicular joint osteomyelitis. We evaluated patients with a diagnosis of sternoclavicular joint osteomyelitis, treated at our hospital from 2002 to 2012. Four treatment options were compared. Three out of twelve patients were successfully cured with antibiotics alone (25%). Debridement with or without negative pressure therapy was successful for one of three patients (33%). Simultaneous debridement, bone resection, and muscle flap coverage of the acquired defect successfully treated one of two patients (50%). Debridement with delayed bone resection and muscle flap coverage was successful in five of five patients (100%). Osteomyelitis of the sternoclavicular joint is a rare disease that has become more prevalent in recent years and can be associated with increasing use of long-term indwelling catheters. Initial debridement with delayed bone resection and pectoralis major muscle flap coverage can effectively treat sternoclavicular joint osteomyelitis.
PMCID: PMC4208504  PMID: 25379557
5.  Robot assisted thoracoscopic resection of giant esophageal leiomyoma 
•Esophageal leiomyoma is most common benign esophageal tumor.•Robot assisted surgery allows for resection of giant esophageal leiomyoma using minimally invasive approach.
Esophageal leiomyoma represents the most common benign esophageal tumor. Robot-assisted thoracoscopic surgery has provided ability to remove it successfully using a minimally invasive approach.
A 63-year old female with history of chronic chest pain presented with an esophageal mass on chest CT and endoscopic ultrasound. Robot-assisted surgery was performed using three robot arms, a camera and an assistant port. A 10 cm leiomyoma was enucleated and removed through a 2 cm myotomy. Completion endoscopy confirmed integrity of the esophagus. Patient's chest pain resolved postoperatively, and she was discharged on postoperative day 3.
Our case describes successful removal of the giant esophageal leiomyoma (10 cm) by robot assisted minimally invasive resection through a 2 cm myotomy.
Use of robot allows for removal of large esophageal leiomyoma. The improved dexterity and patient outcome offered by robot suggests its potential as the mainstay technique for giant esophageal leiomyoma removal.
PMCID: PMC4275859  PMID: 25460487
CT, computed tomography; Endo-GIA, endoscopic gastrointestinal automatic stapler; Esophageal leiomyoma; Robot assisted thoracoscopic surgery; Minimally invasive surgery
6.  Endoscopic management of Boerhaave's syndrome presenting with hematemesis 
Journal of Surgical Case Reports  2014;2014(11):rju110.
Hematemesis is an uncommon yet challenging presentation of Boerhaave's syndrome. Here, we present minimally invasive management of an esophageal perforation with hematemesis using esophageal stenting in an elderly male with multiple comorbidities.
PMCID: PMC4216456  PMID: 25362729
7.  Esophageal cancer: Recent advances in screening, targeted therapy, and management 
The incidence of esophageal cancer remains on the rise worldwide and despite aggressive research in the field of gastrointestinal oncology, the survival remains poor. Much remains to be defined in esophageal cancer, including the development of an effective screening tool, identifying a good tumor marker for surveillance purposes, ways to target esophageal cancer stem cells as well as circulating tumor cells, and developing minimally invasive protocols to treat early-stage disease. The goal of this chapter is to highlight some of the recent advances and ongoing research in the field of esophageal cancer.
PMCID: PMC4229783  PMID: 25395880
Barrett's; cancer stem cells; carcinogenesis/tumorigenesis; dysplasia; esophageal cancer; targeted therapy
8.  AP2β nucleolar localization predicts poor survival after stage I non–small cell lung cancer resection 
The Annals of Thoracic Surgery  2011;92(3):1044-1050.
Activating enhancer-binding protein-2β (AP2β) is a transcription factor involved in apoptosis. The purpose of the current study was to assess the cellular location and level of AP2β in Non-Small Cell Lung Cancer (NSCLC) and normal lung tissue and investigate whether the level and localization of AP2β expression is predictive of overall survival in patients with stage I NSCLC.
We performed immunohistochemical analysis of tissue microarrays (TMAs) prepared from stage I NSCLC specimens with adjacent normal lung tissue from two independent sets of patients who underwent lung resection with curative intent at our institution. AP2β intensity was assessed in TMAs, and AP2β staining patterns were classified as either diffuseor nucleolar in the TMAs. AP2β intensity and localization were analyzed for correlation with patients' survival.
Immunohistochemical analysis of TMAs showed that the intensity of AP2β immunohistochemical staining did not correlate with overall survival. When location of AP2β was analyzed in TMAs, all of the normal lung tissue had diffuse pattern of AP2β. In the first set of NSCLC, patients with nucleolar pattern had a significantly lower 5-year survival rate than patients with diffuse pattern (67% vs. 100%; P = 0.004); this finding was confirmed in the second set (64% vs. 91%; P = 0.02). Multivariate analysis revealed that nucleolar pattern was an independent predictor of poor overall survival in both sets.
The AP2β which is located in the nucleoplasm in normal lung tissue is found in either nucleoplasm or nucleoli in NSCLC. The patients with AP2β in the nucleoli had poor survival compared to patients with AP2β in the cytoplasm.
PMCID: PMC3272351  PMID: 21871297
Lung cancer biology; survival analysis
9.  Fibulin-2 Is a Driver of Malignant Progression in Lung Adenocarcinoma 
PLoS ONE  2013;8(6):e67054.
The extracellular matrix of epithelial tumors undergoes structural remodeling during periods of uncontrolled growth, creating regional heterogeneity and torsional stress. How matrix integrity is maintained in the face of dynamic biophysical forces is largely undefined. Here we investigated the role of fibulin-2, a matrix glycoprotein that functions biomechanically as an inter-molecular clasp and thereby facilitates supra-molecular assembly. Fibulin-2 was abundant in the extracellular matrix of human lung adenocarcinomas and was highly expressed in tumor cell lines derived from mice that develop metastatic lung adenocarcinoma from co-expression of mutant K-ras and p53. Loss-of-function experiments in tumor cells revealed that fibulin-2 was required for tumor cells to grow and metastasize in syngeneic mice, a surprising finding given that other intra-tumoral cell types are known to secrete fibulin-2. However, tumor cells grew and metastasized equally well in Fbln2-null and -wild-type littermates, implying that malignant progression was dependent specifically upon tumor cell-derived fibulin-2, which could not be offset by other cellular sources of fibulin-2. Fibulin-2 deficiency impaired the ability of tumor cells to migrate and invade in Boyden chambers, to create a stiff extracellular matrix in mice, to cross-link secreted collagen, and to adhere to collagen. We conclude that fibulin-2 is a driver of malignant progression in lung adenocarcinoma and plays an unexpected role in collagen cross-linking and tumor cell adherence to collagen.
PMCID: PMC3677922  PMID: 23785517
10.  Human Lung Cancer Cells Grown in an Ex Vivo 3D Lung Model Produce Matrix Metalloproteinases Not Produced in 2D Culture 
PLoS ONE  2012;7(9):e45308.
We compared the growth of human lung cancer cells in an ex vivo three-dimensional (3D) lung model and 2D culture to determine which better mimics lung cancer growth in patients. A549 cells were grown in an ex vivo 3D lung model and in 2D culture for 15 days. We measured the size and formation of tumor nodules and counted the cells after 15 days. We also stained the tissue/cells for Ki-67, and Caspase-3. We measured matrix metalloproteinase (MMP) levels in the conditioned media and in blood plasma from patients with adenocarcinoma of the lung. Organized tumor nodules with intact vascular space formed in the ex vivo 3D lung model but not in 2D culture. Proliferation and apoptosis were greater in the ex vivo 3D lung model compared to the 2D culture. After 15 days, there were significantly more cells in the 2D culture than the 3D model. MMP-1, MMP-9, and MMP-10 production were significantly greater in the ex vivo 3D lung model. There was no production of MMP-9 in the 2D culture. The patient samples contained MMP-1, MMP-2, MMP-9, and MMP-10. The human lung cancer cells grown on ex vivo 3D model form perfusable nodules that grow over time. It also produced MMPs that were not produced in 2D culture but seen in human lung cancer patients. The ex vivo 3D lung model may more closely mimic the biology of human lung cancer development than the 2D culture.
PMCID: PMC3444466  PMID: 23028922
11.  Acute Shingles after Resection of Thoracic Schwannoma 
Texas Heart Institute Journal  2012;39(2):265-267.
Herpes zoster is relatively uncommon after surgery in immunocompetent patients. To our knowledge, there have been no reports of herpes zoster after the resection of a thoracic schwannoma. We report the case of a 48-year-old woman in whom acute shingles developed after the video-assisted thoracic surgical resection of a posterior mediastinal schwannoma adjacent to the 4th thoracic vertebral body. The patient recovered after receiving timely antiviral therapy.
Rash and pain are common in patients who have wound infections and contact dermatitis after surgery, so the possible reactivation of varicella virus might not be prominent in the surgeon's mind. This case serves as a reminder that viral infections such as shingles should be considered in the differential diagnosis of postoperative erythema and pain.
PMCID: PMC3384061  PMID: 22740749
Diagnosis, differential; herpes zoster/diagnosis/epidemiology/etiology; postoperative complications; skin diseases, viral/diagnosis/drug therapy; thoracic surgery, video-assisted; virus activation
12.  Chlamydia pneumoniae Enhances Cytokine-Stimulated Human Monocyte Matrix Metalloproteinases through a Prostaglandin E2-Dependent Mechanism  
Infection and Immunity  2005;73(1):632-634.
Exposure of human monocytes to Chlamydia pneumoniae resulted in a significant enhancement of matrix metalloproteinase (MMP) 1 and 9 production following stimulation with tumor necrosis factor alpha and granulocyte monocyte-colony stimulating factor. The effect of C. pneumoniae on monocyte MMPs was mediated through the induction of prostaglandin E2. These findings may have implications for atherosclerotic plaque rupture.
PMCID: PMC538927  PMID: 15618206

Results 1-12 (12)