Nasopharyngeal carcinoma (NPC) is an Asian-prevalent head and neck cancer with high invasiveness. Although several important risk factors for NPC development have been identified, there is currently ...no preventive strategy for NPC, even in endemic regions. Signal transducer and activator of transcription 3 (STAT3) has been implicated in NPC carcinogenesis, which may serve as a potential target for cancer prevention. Here, we examined the chemopreventive potential of Cucurbitacin I, a natural-occurring selective inhibitor of JAK/STAT3, in NPC models. We hypothesized that Cucurbitacin I would prevent NPC invasion and tumor formation. Our data demonstrated that brief exposure of NPC cells to Cucurbitacin I was sufficient to significantly reduce the in vitro clonogenicity and in vivo tumorigenicity of NPC cells. The chemopreventive potential of Cucurbitacin I was further demonstrated by pre-dosing of the animals with Cucurbitacin I prior to tumor inoculation, which was found to be able to suppress tumor growth up to 7 days post-inoculation. The anti-proliferation activity of Cucurbitacin I was accompanied by downregulation of phospho-STAT3 and STAT3 target gene expression (e.g. cyclin D1 and Mcl-1). Cucurbitacin I also reduced the invasiveness of invasive NPC cell lines with elevated STAT3 activation. Furthermore, our data demonstrated for the first time that Cucurbitacin I harbored potent anoikis-sensitization activity (i.e. sensitizing cancer cells to detachment-induced cell death) against human cancer. Taken together, our results suggested that Cucurbitacin I may be a potent chemopreventive agent for NPC with anti-invasion and anoikis-sensitizing activities.
•The Rat miR-466d expression was up-regulated during CVB virus infection.•Human and rat miR-466 species showed target ‘seed’ regions on CAR mRNA 3′-UTRs.•miR-466 species down-regulated CAR protein ...expression in rat and human, respectively.•miR-466 species were putative negative regulator of CAR.•We reported that miR-466 species had correlation to the anti-viral effect on CVB infection.
This study aimed at elucidating how Coxsackie B virus (CVB) perturbs the host’s microRNA (miRNA) regulatory pathways that lead to antiviral events. The results of miRNA profiling in rat pancreatic cells infection models revealed that rat rno-miR-466d was up-regulated in CVB infection. Furthermore, in silico studies showed that Coxsackie virus and Adenovirus Receptor (CAR), a cellular receptor, was one of the rno-miR-466d targets involved in viral entry. Subsequent experiments also proved that both the rno-miR-466d and the human hsa-miR-466, which are orthologs of the miR-467 gene family, could effectively down-regulate the levels of rat and human CAR protein expression, respectively.
Recent genomic evidence suggests frequent phosphatidylinositide 3-kinase (PI3K) pathway activation in human papillomavirus (HPV) positive oropharyngeal squamous cell carcinoma. ...Mutations/amplification of the gene encoding p110α catalytic subunit of phosphoinositide 3-kinase (PIK3CA), loss of phosphatase and tensin homolog (PTEN) and HRAS mutations are known to activate PI3K pathway.
PIK3CA mutations were identified by Sanger sequencing in 23 of 75 (31%) HPV-positive oropharyngeal carcinomas, including exon 9 (p.E545K n = 10 and p.E542K n = 5) or exon 20 (p.H1047Y, n = 2) mutations. Five rare and one novel (p.R537Q) PIK3CA mutations were identified. HRAS mutation (p.Q61L) was detected in 1 of 62 tested cases. PIK3CA amplification by fluorescence in situ hybridization (FISH) was identified in 4 cases (4/21, 20%), while PTEN loss was seen in 7 (7/21, 33%) cases (chromosome 10 monosomy n = 4, homozygous deletion n = 3).
Overall, genetic alterations that likely lead to PI3K pathway activation were identified in 34 of 75 cases (45%) and did not correlate with disease specific survival. These findings offer a molecular rationale for therapeutic targeting of PI3K pathway in patients with HPV-positive oropharyngeal carcinoma.
c-Met represents an important emerging therapeutic target in cancer. In this study, we demonstrate the mechanism by which c-Met tyrosine kinase inhibition inhibits tumor growth in a highly invasive ...Asian-prevalent head and neck cancer, nasopharyngeal cancer (NPC). c-Met tyrosine kinase inhibitors (TKIs; AM7 and c-Met TKI tool compound SU11274) downregulated c-Met phosphorylation, resulting in marked inhibition of NPC cell growth and invasion. Strikingly, inhibition of c-Met resulted in significant downregulation of TP53-induced Glycolysis and Apoptosis Regulator (TIGAR) and subsequent depletion of intracellular NADPH. Importantly, overexpression of TIGAR ameliorated the effects of c-Met kinase inhibition, confirming the importance of TIGAR downregulation in the growth inhibitory activity of c-Met TKI. The effects of c-Met inhibition on TIGAR and NADPH levels were observed with two different c-Met TKIs (AM7 and SU11274) and with multiple cell lines. As NADPH provides a crucial reducing power required for cell survival and proliferation, our findings reveal a novel mechanistic action of c-Met TKI, which may represent a key effect of c-Met kinase inhibition. Our data provide the first evidence linking c-Met, TIGAR and NADPH regulation in human cancer cells suggesting that inhibition of a tyrosine kinase/TIGAR/NADPH cascade may have therapeutic applicability in human cancers.
Lipid changes with statin treatments vary greatly between individuals for reasons which are largely unknown. This study was performed to examine the genetic determinants of lipid responses to ...rosuvastatin in Chinese patients. A total of 125 polymorphisms in 61 candidate genes from 386 Chinese patients were analyzed for association with the lipid responses to rosuvastatin 10 mg daily. The polymorphisms most highly associated with the low-density lipoprotein cholesterol (LDL-C) response were 421C>A in the ATP-binding cassette G2 gene (P=9.2×10), followed by 18281G>A (V257M) in the flavin-containing monooxygenase 3 gene (P=0.0002), 1421C>G in the lipoprotein lipase gene (P=0.002), and rs4420638 in the apolipoprotein E/C-I/C-IV/C-II gene cluster (P=0.004). Patients with familial hypercholesterolemia had 2.6% smaller reductions in LDL-C compared with patients without familial hypercholesterolemia. This study identified some genetic determinants of LDL-C response to rosuvastatin in Chinese patients, which need to be replicated in other populations.
Summary
Phosphorylated (pi-) protein kinase B (AKT) is commonly expressed in nasopharyngeal carcinoma (NPC) cell lines and tissues, suggesting the involvement of AKT-mammalian target of rapamycin ...(mTOR) signaling in NPC carcinogenesis. This study evaluated the activity of an mTOR inhibitor, RAD001 (Everolimus, Novartis Pharma AG, Switzerland), in 5 NPC cell lines (HK1, HONE-1, CNE-1, CNE-2, C666-1), 2 cisplatin-resistant NPC cell lines and their respective parental cell lines (HK1-LMP1, HONE-1-EBV). RAD001 inhibited cell growth in a dose-dependent manner at nanomolar concentrations in all cell lines. HONE-1 was most sensitive to RAD001 (IC
50
= 0.63 nM, 60% maximal inhibition), while Het-1A (a normal esophageal epithelial cell line) was relatively resistant. No consistent relationship between sensitivity to RAD001 and basal expression of pi-mTOR and pi-p70S6 Kinase-1 (p70S6K) was found. Exposure to RAD001 at picomolar concentrations for 48 h resulted in reduction of pi-mTOR and pi-p70S6K1 expression, but increase in pi-AKT (Ser473) expression in HONE-1 and CNE-1 cell lines. RAD001 significantly induced apoptosis in HONE-1 cells, but has no effect on cell cycle progression. RAD001 exerted an additive to synergistic effect on cisplatin-induced growth inhibition in CNE-1 and HONE-1 cells, and could inhibit the growth of both cisplatin-resistant and cisplatin-sensitive NPC cell lines. In summary, combination of RAD001 and cisplatin maybe a useful therapeutic strategy in NPC. AKT upregulation following RAD001 treatment suggests the presence of a feedback loop on AKT signaling in NPC which warrants further investigation.
Purpose
RAD001 targets at the mammalian target of rapamycin (mTOR), while TKI-258 is a potent tyrosine kinase inhibitor targeting at fibroblast growth factor receptor, vascular endothelial growth ...factor receptor, platelet-derived growth factor receptor and c-kit. We aim to study the activity of combined RAD001 and TKI-258 in cell lines and xenograft model of hepatocellular carcinoma (HCC), with reference to the parallel and upstream pathways of Akt–mTOR axis.
Methods
A panel of 4 human HCC cell lines HepG2, Hep3B, PLC/PRF/5 and Huh7 and the Hep3B-derived xenograft were treated with TKI-258 or/and RAD001, respectively. Related mechanistic studies (including apoptosis and angiogenesis) were conducted.
Results
There was an enhanced increase in suppression of cell proliferation with combined TKI-258 and RAD001 compared with either drug alone. The combination could significantly suppress the phosphorylation of mTOR, MEK1/2 and p38 MAPK. Although the addition of the TKI258 only slightly suppressed the phosphorylation of AKT induced by RAD001, the pi-mTOR and its downstream signaling pathways including pi-p70S6K, pi-S6 and pi-4EBP1 were lowered in the combination. In Hep3B-derived xenograft, TKI-258 and RAD001 had shown an enhanced inhibition of tumor growth without impact on the weight of animals. There was a reduction in microvessel density in the xenograft with the combination, which indicated an enhanced inhibition on angiogenesis. Pro-caspases-3 and PARP cleavage were slightly detected at 48 h after treatment, suggesting that the combination mainly increased the cytostatic arrest ability.
Conclusions
The combination of RAD001 and TKI-258 was active in HCC via inhibition of both mTOR-mediated signaling and its parallel pathways.
Squamous cell carcinoma of the head and neck (SCCHN) is characterized by upregulation of the epidermal growth factor receptor (EGFR). We developed a novel strategy to target EGFR by using a ...therapeutic gene that consisted of an EGFR antisense (AS) gene sequence under U6 promoter control. A phase I clinical trial was conducted to evaluate the safety and biologic effects of EGFR AS.
Patients with advanced SCCHN who were refractory to standard therapies and who had at least one assessable and accessible lesion were enrolled. The EGFR AS dose was escalated in successive cohorts (six dose levels; 60 to 1,920 microg/injection). Patients received four weekly intratumoral EGFR AS injections. Tumor biopsies were performed before and after completion of therapy. Treatment response was assessed by tumor volume measurements (positron emission tomography/computed tomography), and levels of target proteins were assessed by immunohistochemistry.
Seventeen assessable patients were treated. No grades 3 to 4 or dose-limiting toxicities were noted, and a maximum-tolerated dose was not reached. Five patients (29%) achieved a clinical response, which included two complete responses (CRs) and three partial responses (PRs); two additional patients had stable disease (SD) as the best response. Patients with disease control (CR + PR + SD) had tumors with higher EGFR and lower STAT3 expression at baseline compared with patients who had progressive disease (P = .0312 and P = .095, respectively).
Intratumoral EGFR AS was safe and resulted in antitumor activity in patients with advanced SCCHN. Baseline levels of high EGFR and low STAT3 may be associated with antitumor effects.
Direct‐to‐consumer genetic testing (DTCGT) is gaining popularity in Hong Kong (HK). As DTCGT forgoes specialist medical involvement, healthcare professionals have raised concerns regarding its ...validity, utility, and the public's ability to interpret DTCGT results. Thus, genetic counseling (GC) is recommended to facilitate understanding of DTCGT. This study aimed to investigate HK public's perception toward DTCGT and the importance of GC in DTCGT. A total of 304 HK adults were invited to complete a 37‐item survey online. Participants’ genomic literacy, understanding and attitude toward DTCGT and GC, and responses to a mock DTCGT scenario were assessed. 48% of participants were aware of DTCGT while 82% indicated an interest. 30% of participants were aware of GC services in HK; 49% were interested in GC services for understanding DTCGT results. Participants scored on average 7.6/11 in the genomic sequencing knowledge scale and were weak in limitations of genomic testing. In the mock DTCGT scenario, 73% of participants expressed concern with the positive results initially. After being explained limitations of DTCGT, 40% of participants reported decreased concern. Reduced perceived helpfulness in medical management and lifestyle modification were also reported by 35% and 27%, respectively. This HK population demonstrated a high level of awareness and interest in DTCGT. As potential DTCGT users, they might experience excess concern and overestimate the usefulness of positive DTCGT results, particularly in medical management. The importance of GC to educate and guide interpretation of DTCGT results is supported; yet the awareness and access of GC services is inadequate in HK.
Randomized clinical trials demonstrate no benefit for epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors in unselected patients with head and neck squamous cell carcinoma (HNSCC). ...However, a patient with stage IVA HNSCC received 13 days of neoadjuvant erlotinib and experienced a near-complete histologic response.
To determine a mechanism of exceptional response to erlotinib therapy in HNSCC.
Single patient with locally advanced HNSCC who received erlotinib monotherapy in a window-of-opportunity clinical trial (patients scheduled to undergo primary cancer surgery are treated briefly with an investigational agent). Whole-exome sequencing of pretreatment tumor and germline patient samples was performed at a quaternary care academic medical center, and a candidate somatic variant was experimentally investigated for mediating erlotinib response.
A brief course of erlotinib monotherapy followed by surgical resection.
Identification of pretreatment tumor somatic alterations that may contribute to the exceptional response to erlotinib. Hypotheses were formulated regarding enhanced erlotinib response in preclinical models harboring the patient tumor somatic variant MAPK1 E322K following the identification of tumor somatic variants.
No EGFR alterations were observed in the pretreatment tumor DNA. Paradoxically, the tumor harbored an activating MAPK1 E322K mutation (allelic fraction 0.13), which predicts ERK activation and erlotinib resistance in EGFR-mutant lung cancer. The HNSCC cells with MAPK1 E322K exhibited enhanced EGFR phosphorylation and erlotinib sensitivity compared with wild-type MAPK1 cells.
Selective erlotinib use in HNSCC may be informed by precision oncology approaches.
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