Helical Nanographenes Bearing Pentagon-Heptagon Pairs by Stepwise Dehydrocyclization.

The incorporation of pentagon-heptagon pairs into helical nanographenes lacks a facile synthetic route, and the impact of these pairs on chiroptical properties remains unclear. In this study, a method for the stepwise construction of pentagon-heptagon pairs in helical nanographenes by the dehydrogenation of [6]helicene units was developed. Three helical nanographenes containing pentagon-heptagon pairs were synthesized and characterized using this approach. A wide variation in the molecular geometries and photophysical properties of these helical nanographenes was observed, with changes in the helical length of these structures and the introduction of the pentagon-heptagon pairs. The embedded pentagon-heptagon pairs reduced the oxidation potential of the synthesized helical nanographenes. The high isomerization energy barriers enabled the chiral resolution of the helicene enantiomers. Chiroptical investigations revealed remarkably enhanced circularly polarized luminescence and luminescence dissymmetry factors with an increasing number of the pentagon-heptagon pairs.

ANXA1 Binds and Stabilizes EphA2 to Promote Nasopharyngeal Carcinoma Growth and Metastasis.

Overexpression of ANXA1 and EphA2 has been linked to various cancers and both proteins have attracted considerable attention for the development of new anticancer drugs. Here we report that ANXA1 competes with Cbl for binding EphA2 and increases its stability by inhibiting Cbl-mediated EphA2 ubiquitination and degradation in nasopharyngeal carcinoma (NPC). Binding of ANXA1 to EphA2 promoted NPC cell growth and metastasis in vitro and in vivo by elevating EphA2 levels and increasing activity of EphA2 oncogenic signaling (pS897-EphA2). Expression of ANXA1 and EphA2 was positively correlated and both were significantly higher in NPC tissues than in the normal nasopharyngeal epithelial tissues. Patients with high expression of both proteins presented poorer disease-free survival and overall survival relative to patients with high expression of one protein alone. Furthermore, amino acid residues 20-30aa and 28-30aa of the ANXA1 N-terminus bound EphA2. An 11 amino acid-long ANXA1-derived peptide (EYVQTVKSSKG) was developed on the basis of this N-terminal region, which disrupted the connection of ANXA1 with EphA2, successfully downregulating EphA2 expression and dramatically suppressing NPC cell oncogenicity in vitro and in mice. These findings suggest that ANXA1 promotes NPC growth and metastasis via binding and stabilization of EphA2 and present a strategy for targeting EphA2 degradation and treating NPC with a peptide. This therapeutic strategy may also be extended to other cancers with high expression of both proteins. SIGNIFICANCE: These findings show that EphA2 is a potential target for NPC therapeutics and an ANXA1-derived peptide suppresses NPC growth and metastasis. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/20/4386/F1.large.jpg.

Long non-coding RNA ZNF674-1 acts as a cancer suppressor in nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is the most frequently occurring carcinoma of the head and neck. The complexity of NPC makes it difficult for it to be diagnosed and treated at an early stage. Certain long non-coding RNAs (lncRNAs) are closely associated with the carcinogenesis of NPC. In the present study, the expression of lncRNA ZNF674-1 in NPC tissues and an NPC cell line was analyzed and was revealed to be downregulated compared with normal tissues and cells. When the expression of lncRNA ZNF674-1 was reduced in NPC cells, the proliferation, migration and invasion of these cells was promoted, whereas the apoptosis of these cells was decreased. On the contrary, when overexpressed, the expression of lncRNA ZNF674-1 inhibited the proliferation, invasion and migration of cells, but promoted cell apoptosis. The results of the present study reveal that the lncRNA ZNF67-1 may restrain the carcinogenesis of NPC, and may also serve as a potential biomarker for the early diagnosis and treatment of NPC.

Histone acetyltransferase 1 up regulates Bcl2L12 expression in nasopharyngeal cancer cells.

The deregulation of Bcl2L12 expression in cancer has been recognized, but the causative factors are unknown. Histone acetyltransferases (HAT) play critical roles in the regulation gene transcription. This study tests a hypothesis that the aberrant activities of HAT induce deregulation of Bcl2L12 in nasopharyngeal cancer (NPC). In this study, human NPC tissues were collected from the clinic. The expression of Bcl2L12 and HATs in NPC cells was analyzed by real time RT-PCR and Western blotting. NPC cell apoptosis was analyzed by flow cytometry. The results showed that by screening the subtypes of HAT, the levels of HAT1 were uniquely higher in NPC as compared with non-cancer nasopharyngeal tissue. The levels of Bcl2L12 in NPC cells were positively correlated with HAT1. HAT1 involved in the STAT5 binding to the Bcl2L12 promoter. HAT1 increased the expression of Bcl2L12. Bcl2L12 mediated the effects of HAT1 on suppressing NPC cell apoptosis. Absorption of the HAT1 shRNA plasmid-carrying liposomes induced NPC cell apoptosis. In conclusion, inhibition of HAT1 can induce NPC cell apoptosis via increasing Bcl2L12 expression, which can be a potential therapy for NPC treatment.

lncRNA C22orf32-1 contributes to the tumorigenesis of nasopharyngeal carcinoma.

The mechanism of nasopharyngeal carcinoma (NPC) remains unclear. The present study investigated the abnormal expression of long non-coding (lnc)RNAs in NPC tissues and one NPC cell line to identify the involvement of lncRNAs in the tumorigenesis of NPC. Using a quantitative reverse transcription polymerase chain reaction (RT-qPCR), the expression of lncRNA C22orf32-1 in NPC tissues and an NPC cell line was verified. The effects of lncRNA C22orf32-1 on NPC cells were investigated with a cell proliferation assay, cell scratch assay, Transwell assay and a cell apoptosis assay. The expression levels of lncRNA C22orf32-1 in NPC tissues and an NPC cell line were upregulated. lncRNA C22orf32-1 promoted the proliferation, migration and invasion of NPC cells, and reduced the apoptosis of NPC cells. The data demonstrated that lncRNA C22orf32-1 may facilitate the tumorigenesis of NPC, and may be used for the early diagnosis and treatment of NPC.

GALNT7, a target of miR-494, participates in the oncogenesis of nasopharyngeal carcinoma.

GalNAc-transferase-7 (GALNT7) is essential for the regulation of cell proliferation and has been implicated in tumorigenesis. However, the role of GALNT7 in the development and progression of nasopharyngeal carcinoma (NPC) remains unclear. Our previous study showed that GALNT7 was a putative target of miR-494, which was confirmed by luciferase reporter assay. In the present study, we demonstrated that in vitro knockdown of GALNT7 significantly inhibited the proliferation, colony formation, migration, and invasion of NPC-derived cells. In vivo tumorigenicity assay showed that miR-494 and GALNT7-small interfering RNA (siRNA) reduced tumor growth in nude mice. Taken together, our results provided new evidence for an oncogenic role of GALNT7 in NPC.

Functional elucidation of miR-494 in the tumorigenesis of nasopharyngeal carcinoma.

Nasopharyngeal carcinoma has very high incidence and high mortality worldwide. MiRNA is related to the tumorigenesis and metastasis of a variety of tumors. In the present study, we verify that the expression of miR-494 in NPC tissues and NPC-derived cells was down-regulated, respectively. The proliferation, colony formation, migration, and invasion of NPC-derived cells were suppressed, while the cell apoptosis was promoted, when miR-494 was over-expressed in these cells. GALNT7 and CDK16 were confirmed to be the direct targets of miR-494. These results suggested that miR-494 play an inhibitory role in the tumorigenesis of NPC.

[Curative effect of transtympanic perfusion of gentamicin on unilateral Ménière's disease].

OBJECTIVE: To investigate the curative effect of transtympanic perfusion of gentamicin on unilateral Ménière's disease. METHODS: Twenty-three patients with unilateral Ménière's disease, 14 males and 9 females, aged 24 - 61, all with vertigo, tinnitus and ear fullness sensation to different degrees, were treated with transtympanic perfusion of gentamicin via the tympanostomy tube, 12 mg per 3 hours and 5 times a day. Pure tone audiometry and caloric test were performed every day before treatment. When destruction type of nystagmus was observed by Frenzel's glasses and the treated ear showed no response to caloric test, the treatment was ceased. After the treatment the patients were followed up for 9 - 11 years (10.2 years on average). RESULTS: The average amount of gentamicin used was 216 mg. The treatment lasted for 1.5 to 5 days (3.6 days on average). Vertigo disappeared in 21 patients (91%) and remained unchanged in 2. Hearing was improved or remained unchanged in 17 patients (73%) and became worse in 6. Tinnitus decreased or disappeared in 15 patients (66%), and increased in 2 patients. Ear fullness sensation decreased or disappeared in 21 patients (91%). and remained unchanged in 2. Twenty-one patients were completely recovered and returned to work (91%). CONCLUSION: Relieving intractable vertigo and preserving hearing, transtympanic perfusion of gentamicin is effective on unilateral Ménière's disease.