The Interplay of MicroRNA-34a, LGR4, EMT-Associated Factors, and MMP2 in Regulating Uveal Melanoma Cells.

Purpose: MicroRNA-34a (miR-34a) has been implicated in many biological processes. It is downregulated in uveal melanoma, and introduction of miR-34a inhibits the proliferation and migration of uveal melanoma cells. Leucine-rich repeat-containing G protein-coupled receptor 4 (LGR4) is a novel target of miR-34a identified first in retinal pigment epithelial cells. In this study, we sought to evaluate the interaction of miR-34a and LGR4 in uveal melanoma and its downstream mechanisms. Methods: The expression of LGR4, epithelial-mesenchymal transition (EMT)-associated factors, and matrix metalloproteinase 2 (MMP2) in uveal melanoma cells was assessed by immunoblotting and immunofluorescence analysis. MicroRNA-34a mimic molecules, LGR4 small interfering RNA (siRNA), or MMP2-specific siRNA were transiently transfected into uveal melanoma cells. In vitro scratch and Transwell assays were used to evaluate the migratory and invasive potential of the resultant uveal melanoma cells. Results: LGR4 is upregulated in uveal melanoma cells. Introduction of miR-34a significantly decreased the expression level of LGR4. Transfection with miR-34a or knockdown of LGR4 attenuated the aggressiveness of uveal melanoma cells. In addition, there was a decrease in the expression of mesenchymal markers N-cadherin, vimentin, and Snail following miR-34a introduction or knockdown of LGR4. Finally, MMP2 was found to be a downstream effector for miR-34a and LGR4 that regulates the migration and invasion of uveal melanoma cells. Conclusions: MicroRNA-34a negatively controls LGR4, thereby inhibiting the migration and invasion of uveal melanoma cells. Ultimately, both miR-34a and LGR4 impact the aggressiveness of uveal melanoma with alterations in the markers of the EMT. MMP2 is a downstream effector that influences the metastasis seen with uveal melanoma cells.

Large fungating basal cell carcinoma of the dorsum of the foot: A case report.

Basal cell carcinoma is the most common skin cancer, but may present as anatomically and pathologically unique variants. A careful understanding of the pathophysiology, meticulous preoperative planning, and the use of unique reconstructive techniques to preserve function and cosmesis are key in achieving a satisfactory oncologic result.

Evolution in the surgical management of gastric cancer: is extended lymph node dissection back in vogue in the USA?

BACKGROUND: Gastric cancer remains a formidable treatment challenge. For decades, treatment consisted mostly of surgical intervention for this deadly disease. With improvements in the multi-disciplinary management of solid organ malignancies, the approach to this disease is being stepwise refined. MAIN BODY: One of the prevalent controversies in the surgical management of gastric cancer rests on the need for adequate harvesting of lymph nodes. For decades, lymph node dissection is regarded as a staging technique useful in only upstaging the disease. The adoption of D2 lymphadenectomy has been particularly slow to mature. But with prevailing data from Asia consistently demonstrating a survival benefit from lymphadenectomy, it calls into question the notion of lymphadenectomy as being solely a staging procedure. CONCLUSIONS: As gastric resection techniques are being better defined in western countries and surgical morbidities lowered on its execution, D2 lymphadenectomy is becoming more accepted as the new standard in the management of gastric cancer.

Management of afferent loop obstruction from recurrent metastatic pancreatic cancer using a venting gastrojejunostomy.

Pancreatic cancer is an aggressive malignancy potentially curable with surgical intervention. Following pancreaticoduodenectomy for suspected pancreatic head malignancy, patients have a high risk for both immediate and delayed problems due to surgical complications and recurrent disease. We report here a patient with pancreatic cancer treated with pancreaticoduodenectomy who developed recurrent disease resulting in obstruction of the afferent limb. The patient developed biliary obstruction and cholangitis at presentation. Her biliary tree failed to dilate which precluded safe percutaneous biliary decompression. During surgical exploration, she was found to have a dilated afferent limb at the level of the transverse mesocolon. The patient underwent decompression of the afferent limb as well as the biliary tree using a venting gastrojejunostomy to the blind loop. This represents a novel surgical approach for management of this complicated and difficult problem.

Double contrast-enhanced ultrasonography for the preoperative evaluation of gastric cancer: a comparison to endoscopic ultrasonography with respect to histopathology.

BACKGROUND: This study was designed to compare the accuracy of endoscopic ultrasound (EUS) with double contrast-enhanced ultrasound (DCUS) in the staging of gastric malignancies. DCUS is a transabdominal ultrasound technique using both intravenous and intraluminal contrast to enhance sonographic visualization. METHODS: This retrospective study included 162 patients with biopsy-proven gastric cancer who underwent DCUS and EUS preoperatively with the ultrasound results compared with the pathologic findings of the resected specimens. RESULTS: The overall accuracy of DCUS and EUS for tumor (T) staging was 77.2% and 74.7%, respectively. Comparison of ultrasound techniques for T staging revealed that DCUS was superior to EUS only for a tumor depth of T3 (chi-square, P = .025). Lymph nodes were staged correctly with DCUS and EUS in 78.4% and 57.4% of cases, respectively (chi-square, P = .001). CONCLUSIONS: DCUS offers a noninvasive approach for the staging of gastric cancer. DCUS was comparable to EUS in tumor depth evaluation but offered an advantage in lymph node detection.

GPR48-Induced keratinocyte proliferation occurs through HB-EGF mediated EGFR transactivation.

GPR48 can mediate keratinocyte proliferation and migration. Our investigations showed that AG1478, an inhibitor of EGFR tyrosine kinase, could block GPR48-mediated cellular processes. AG1478 treatment of Gpr48(+/+) cells also decreased phosphorylation of EGFR, ERK and STAT3. Subsequent screening using conditioned media immunodepleted of EGFR ligands identified HB-EGF as the ligand responsible for phosphorylation of EGFR, ERK and STAT3. HB-EGF was reduced in Gpr48(-/-) cell culture medium, but its addition restored the phosphorylation of EGFR, ERK, STAT3, as well as cell proliferation. Confirmation that GPR48 mediates EGFR signaling pathway through HB-EGF was subsequently performed using an inhibitor of HB-EGF.

MicroRNA-1/206 targets c-Met and inhibits rhabdomyosarcoma development.

MicroRNAs (miRNAs) are endogenous short (approximately 22) nucleotide RNAs that regulate gene function by modification of target mRNAs. miRNA-1 (miR-1) and miRNA-206 (miR-206) are highly expressed in skeletal muscle. Due to the tissue-specific nature of miR-1/206 for skeletal muscles, we investigated the role of miR-1/206 in the development of rhabdomyosarcoma. Initially, we demonstrated that miR-1/206 expression was suppressed in rhabdomyosarcomas and found at very low levels in a rhabdomyosarcoma RD cell line. Transient transfection of miR-1/206 into cultured RD cells led to a significant decrease in cell growth and migration. Using bioinformatics, we identified two putative miR-1/206 binding sites within the 3'-untranslated region of the human c-Met mRNA. miR-1/206 was then shown to have activity on mRNA expression by targeting the c-Met 3'-untranslated region. The expression of c-Met protein was shown to be down-regulated by subsequent Western blot analysis. Conversely, up-regulation of c-Met was confirmed in tissue samples of human rhabdomyosarcoma, with its level inversely correlated with miR-1/206 expression. In vivo, miR-1/206-expressing tumor cells showed growth delay in comparison with negative control. Our results demonstrated that miR-1/206 suppressed c-Met expression in rhabdomyosarcoma and could function as a potent tumor suppressor in c-Met-overexpressing tumors. Inhibition of miR-1/206 function could contribute to aberrant cell proliferation and migration, leading to rhabdomyosarcoma development.

High mobility group box I (HMGB1) release from tumor cells after treatment: implications for development of targeted chemoimmunotherapy.

We have recently demonstrated that cytolysis of human melanoma cells by immune effectors (both NK and T cells) is associated with release of the nuclear chromatin protein, high mobility group box I (HMGB1). Extracellular HMGB1 mediates a number of important functions including endothelial cell activation, stromagenesis, recruitment and activation of innate immune cells, and also dendritic cell maturation that, in the setting of cancer, lead to a chronic inflammatory response. This reparative inflammatory response promotes tumor cell survival, expansion, and metastases. Release of HMGB1 after chemotherapy-induced cytotoxicity has not been well characterized. We measured the release of HMGB1 after chemotherapy or immune cytolysis and demonstrated that this did not correlate with conventional markers of apoptosis and necrosis in several human colorectal, pancreatic, and melanoma tumor cell lines. Rather, we observed that tumor cells incubated with the platinating agent oxaliplatin, retained HMGB1 within the nucleus for significantly longer periods than other agents used at comparable cytotoxic concentrations or even with potent cytolytic cells. Thus, release of HMGB1 from dying tumor cells treated with chemotherapy or cells with lymphokine activated killer cell activity is not dependent solely on the mode of cell death. Sequestration of the damage associated molecular pattern molecule, HMGB1, may play a role in the clinical efficacy of platinating agents and suggests this as a superior agent for coupling with immunotherapeutic strategies, possibly enhancing their effectiveness.

Efficacy and safety of intravenous injection of lidocaine in the treatment of acute primary angle-closure glaucoma: a pilot study.

AIMS: To study the safety and effectiveness of a combination of both intravenous injection of lidocaine and intraocular pressure-lowering medications, in the intraocular pressure control and relief of symptoms of refractory acute primary angle-closure glaucoma (PACG). METHODS: Five consecutive patients with their first attack of acute PACG, with intraocular pressure > or = 45 mmHg and a failure to release from the attack under antiglaucomatous medications for 4 hours, were recruited into the study. On presentation, each patient received topical pilocarpine and timolol, and systemic acetazolamide and mannitol as primary treatment. Then the patients accepted 2% lidocaine by intravenous injection at dose of 0.8 mg/kg in concert with antiglaucomatous medications. The intraocular pressures after intravenous injection at 30 minutes, and then at 1, 2, 4, 12, and 24 hours, were documented by applanation tonometry. Symptoms, visual acuity, intraocular pressure, corneal edema, angle status on gonioscopy, pupillary size, and reaction were also measured. RESULTS: Six eyes of five patients seen with acute PACG were recruited. The mean intraocular pressure was reduced from 50.83 +/- 5.34 mmHg to 39.5 +/- 3.45 mmHg at 30 minutes after intravenous injection, and then to 33.3 +/- 3.56 mmHg at 1 hour, and 24.55 +/- 5.09 mmHg at 2 hours after intravenous injection. The mean intraocular pressure was less than 21 mmHg at 4 hours and beyond. There was instant symptomatic relief for all patients. No complications were encountered. CONCLUSIONS: From this preliminary study, intravenous injection of lidocaine seems to be safe and effective in controlling intraocular pressure and eliminating symptoms in acute PACG. But the exact efficacy and safety need further investigation in large case studies.