Establishment and Characterization of an Epstein-Barr Virus-positive Cell Line from a Non-keratinizing Differentiated Primary Nasopharyngeal Carcinoma.

Nasopharyngeal carcinoma (NPC), a cancer that is etiologically associated with the Epstein-Barr virus (EBV), is endemic in Southern China and Southeast Asia. The scarcity of representative NPC cell lines owing to the frequent loss of EBV episomes following prolonged propagation and compromised authenticity of previous models underscores the critical need for new EBV-positive NPC models. Herein, we describe the establishment of a new EBV-positive NPC cell line, designated NPC268 from a primary non-keratinizing, differentiated NPC tissue. NPC268 can undergo productive lytic reactivation of EBV and is highly tumorigenic in immunodeficient mice. Whole-genome sequencing revealed close similarities with the tissue of origin, including large chromosomal rearrangements, while whole-genome bisulfite sequencing and RNA sequencing demonstrated a hypomethylated genome and enrichment in immune-related pathways, respectively. Drug screening of NPC268 together with six other NPC cell lines using 339 compounds, representing the largest high-throughput drug testing in NPC, revealed biomarkers associated with specific drug classes. NPC268 represents the first and only available EBV-positive non-keratinizing differentiated NPC model, and extensive genomic, methylomic, transcriptomic, and drug response data should facilitate research in EBV and NPC, where current models are limited. SIGNIFICANCE: NPC268 is the first and only EBV-positive cell line derived from a primary non-keratinizing, differentiated nasopharyngeal carcinoma, an understudied but important subtype in Southeast Asian countries. This model adds to the limited number of authentic EBV-positive lines globally that will facilitate mechanistic studies and drug development for NPC.

Contribution of mutant HSC clones to immature and mature cells in MDS and CMML, and variations with AZA therapy.

Myelodysplastic neoplasms (MDSs) and chronic myelomonocytic leukemia (CMML) are clonal disorders driven by progressively acquired somatic mutations in hematopoietic stem cells (HSCs). Hypomethylating agents (HMAs) can modify the clinical course of MDS and CMML. Clinical improvement does not require eradication of mutated cells and may be related to improved differentiation capacity of mutated HSCs. However, in patients with established disease it is unclear whether (1) HSCs with multiple mutations progress through differentiation with comparable frequency to their less mutated counterparts or (2) improvements in peripheral blood counts following HMA therapy are driven by residual wild-type HSCs or by clones with particular combinations of mutations. To address these questions, the somatic mutations of individual stem cells, progenitors (common myeloid progenitors, granulocyte monocyte progenitors, and megakaryocyte erythroid progenitors), and matched circulating hematopoietic cells (monocytes, neutrophils, and naïve B cells) in MDS and CMML were characterized via high-throughput single-cell genotyping, followed by bulk analysis in immature and mature cells before and after AZA treatment. The mutational burden was similar throughout differentiation, with even the most mutated stem and progenitor clones maintaining their capacity to differentiate to mature cell types in vivo. Increased contributions from productive mutant progenitors appear to underlie improved hematopoiesis in MDS following HMA therapy.

Genome-wide CRISPR screens of oral squamous cell carcinoma reveal fitness genes in the Hippo pathway.

New therapeutic targets for oral squamous cell carcinoma (OSCC) are urgently needed. We conducted genome-wide CRISPR-Cas9 screens in 21 OSCC cell lines, primarily derived from Asians, to identify genetic vulnerabilities that can be explored as therapeutic targets. We identify known and novel fitness genes and demonstrate that many previously identified OSCC-related cancer genes are non-essential and could have limited therapeutic value, while other fitness genes warrant further investigation for their potential as therapeutic targets. We validate a distinctive dependency on YAP1 and WWTR1 of the Hippo pathway, where the lost-of-fitness effect of one paralog can be compensated only in a subset of lines. We also discover that OSCCs with WWTR1 dependency signature are significantly associated with biomarkers of favorable response toward immunotherapy. In summary, we have delineated the genetic vulnerabilities of OSCC, enabling the prioritization of therapeutic targets for further exploration, including the targeting of YAP1 and WWTR1.

Many types of cancer now have 'targeted treatments', which specifically home in on genes cancer cells rely on for survival. But there are very few of these treatments available for the most common type of mouth cancer, oral squamous cell carcinoma, which around 350,000 people are diagnosed with each year. Designing targeted treatments relies on detailed knowledge of the genetic makeup of the cancer cells. But, little is known about which genes drive oral squamous cell carcinoma, especially among patients living in Asia, which is where over half of yearly cases are diagnosed. One way to resolve this is to use gene editing technology to find the genes that the cancer cells need to survive. Now, Chai et al. have used a gene editing tool known as CRISPR to examine 21 cell lines from patients diagnosed with oral squamous cell carcinoma. Most of these lines were from Asian patients, some of whom had a history of chewing betel quid which increases the risk of mouth cancer. By individually inactivating genes in these cell lines one by one, Chai et al. were able to identify 918 genes linked to the survival of the cancer cells. Some of these genes have already been associated with the spread of other types of cancer, whereas others are completely unique to oral squamous cell carcinoma. The screen also discovered that some cell lines could not survive without genes involved in a signalling pathway called Hippo, which is known to contribute to the progression of many other types of cancer. Uncovering the genes associated with oral squamous cell carcinoma opens the way for the development of new targeted treatments. Targeted therapies already exist for some of the genes identified in this study, and it may be possible to repurpose them as a treatment for this widespread mouth cancer. But, given that different cell lines relied on different genes to survive, the next step will be to identify which genes to inactivate in each patient.

Current Perspectives on Nasopharyngeal Carcinoma.

Of the ~129,079 new cases of nasopharyngeal carcinoma (NPC) and 72,987 associated deaths estimated for 2018, the majority will be geographically localized to South East Asia, and likely to show an upward trend annually. It is thought that disparities in dietary habits, lifestyle, and exposures to harmful environmental factors are likely the root cause of NPC incidence rates to differ geographically. Genetic differences due to ethnicity and the Epstein Barr virus (EBV) are likely contributing factors. Pertinently, NPC is associated with poor prognosis which is largely attributed to lack of awareness of the salient symptoms of NPC. These include nose hemorrhage and headaches and coupled with detection and the limited therapeutic options. Treatment options include radiotherapy or chemotherapy or combination of both. Surgical excision is generally the last option considered for advanced and metastatic disease, given the close proximity of nasopharynx to brain stem cell area, major blood vessels, and nerves. To improve outcome of NPC patients, novel cellular and in vivo systems are needed to allow an understanding of the underling molecular events causal for NPC pathogenesis and for identifying novel therapeutic targets and effective therapies. While challenges and gaps in current NPC research are noted, some advances in targeted therapies and immunotherapies targeting EBV NPCs are discussed in this chapter, which may offer improvements in outcome of NPC patients.

The 4717C > G polymorphism in periplakin modulates sensitivity to EGFR inhibitors.

The use of EGFR inhibitors on oral squamous cell carcinoma (OSCC) as monotherapy yielded modest clinical outcomes and therefore would benefit from biomarkers that could predict which patient subsets are likely to respond. Here, we determined the efficacy of erlotinib in OSCC cell lines, and by comparing sensitive and resistant lines to identify potential biomarkers. We focused on the 4717C > G polymorphism in periplakin (PPL) where the CC genotype was associated with erlotinib resistance. To validate this, erlotinib-resistant cell lines harbouring CC genotype were engineered to overexpress the GG genotype and vice versa. Isogenic cell lines were then studied for their response to erlotinib treatment. We demonstrated that overexpression of the GG genotype in erlotinib-resistant lines sensitized them to erlotinib and inhibition of AKT phosphorylation. Similarly, the expression of the CC genotype conferred resistance to erlotinib with a concomitant increase in AKT phosphorylation. We also demonstrated that cell lines with the CC genotype generally are more resistant to other EGFR inhibitors than those with the GG genotype. Overall, we showed that a specific polymorphism in the PPL gene could confer resistance to erlotinib and other EGFR inhibitors and further work to evaluate these as biomarkers of response is warranted.

Canthin-6-one Isolated from Bruceajavanica Root Blocks Cancer Cells in the G2/M phase and Synergizes with Cisplatin.

Poor prognosis of most cancer patients is in part, due to limited therapeutic options. Furthermore, as chemotherapy remains the standard-of-care for several cancers, partial or lack of response remains a concern and compounding this are the adverse side effects of the treatment that severely impacts the quality of life and survival. In pursuit of improving treatment options, we have opted to investigate the unique chemical skeleton of natural compounds as anticancer therapies. In this study, from an initial screen of 31 crude methanol extracts from -15 plant species using HL60 cells, the root extract of Bruceajavanica (L.) Merr indicated the presence of bioactive compounds. Subsequent bioassay-guided purification on the root extract yielded two alkaloids canthin-6-one (1) and bruceolline J (2), which were further investigated for their bioactivity in representative human cancer lines and normal phenotypic counterparts. MTT assay demonstrated ED50 values from 34.7-72.9 gM for 1 and 16.0-54.0 gM for 2 for the cancer cell lines panel. NP69 cells also demonstrated sensitivity to. both compounds (9.3 piM and 4.5 pM). As amount of 2 isolated were limiting, we focused on 1 to further identify novel anticancer properties in PC3 and HeLa cancer lines. We observed at 30 gM, I induced a G2/M phase arrest coinciding with decreased cell proliferation. Furthermore, I was able to synergize the cytotoxic effect of cisplatin when used in combination, suggesting the potential of combination therapy for those less responsive lesions to standard chemotherapy.

Copper supplementation amplifies the anti-tumor effect of curcumin in oral cancer cells.

BACKGROUND: Oral cancer is the sixth most common cancer worldwide and 90% of oral malignancies are caused by oral squamous cell carcinoma (OSCC). Curcumin, a phytocompound derived from turmeric (Curcuma longa) was observed to have anti-cancer activity which can be developed as an alternative treatment option for OSCC. However, OSCC cells with various clinical-pathological features respond differentially to curcumin treatment. HYPOTHESIS: Intracellular copper levels have been reported to correlate with tumor pathogenesis and affect the sensitivity of cancer cells to cytotoxic chemotherapy. We hypothesized that intracellular copper levels may affect the sensitivity of oral cancer cells to curcumin. METHODS: We analysed the correlation between intracellular copper levels and response to curcumin treatment in a panel of OSCC cell lines derived from oral cancer patients. Exogenous copper was supplemented in curcumin insensitive cell lines to observe the effect of copper on curcumin-mediated inhibition of cell viability and migration, as well as induction of oxidative stress and apoptosis. Protein markers of cell migration and oxidative stress were also analysed using Western blotting. RESULTS: Concentrations of curcumin which inhibited 50% OSCC cell viability (IC50) was reduced up to 5 times in the presence of 250 µM copper. Increased copper level in curcumin-treated OSCC cells was accompanied by the induction of intracellular ROS and increased level of Nrf2 which regulates oxidative stress responses in cells. Supplemental copper also inhibited migration of curcumin-treated cells with enhanced level of E-cadherin and decreased vimentin, indications of suppressed epithelial-mesenchymal transition. Early apoptosis was observed in combined treatment but not in treatment with curcumin or copper alone. CONCLUSION: Supplement of copper significantly enhanced the inhibitory effect of curcumin treatment on migration and viability of oral cancer cells. Together, these findings provide molecular insight into the role of copper in overcoming insensitivity of oral cancer cells to curcumin treatment, suggesting a new strategy for cancer therapy.

Utilizing Zebrafish to Identify Anti-(Lymph)Angiogenic Compounds for Cancer Treatment: Promise and Future Challenges.

Cancer metastasis which predominantly occurs through blood and lymphatic vessels, is the leading cause of death in cancer patients. Consequently, several anti-angiogenic agents have been approved as therapeutic agents for human cancers such as metastatic renal cell carcinoma. Also, anti-lymphangiogenic drugs such as monoclonal antibodies VGX-100 and IMC-3C5 have undergone phase I clinical trials for advanced and metastatic solid tumors. Although anti-tumor-associated angiogenesis has proven to be a promising therapeutic strategy for human cancers, this approach is fraught with toxicities and development of drug resistance. This emphasizes the need for alternative anti-(lymph)angiogenic drugs. The use of zebrafish has become accepted as an established model for high-throughput screening, vascular biology, and cancer research. Importantly, various zebrafish transgenic lines have now been generated that can readily discriminate different vascular compartments. This now enables detailed in vivo studies that are relevant to both human physiological and tumor (lymph)angiogenesis to be conducted in zebrafish. This review highlights recent advancements in the zebrafish anti-vascular screening platform and showcases promising new anti-(lymph)angiogenic compounds that have been derived from this model. In addition, this review discusses the promises and challenges of the zebrafish model in the context of anti-(lymph)angiogenic compound discovery for cancer treatment.

A Population-Based Cohort Study of All-Cause and Site-Specific Cancer Incidence Among Patients With Type 1 Diabetes Mellitus in Taiwan.

BACKGROUND: The relationship between type 1 diabetes mellitus (T1DM) and cancer incidence remains unclear. We sought to assess the all-cause and site-specific cancer incidence in patients with T1DM. METHODS: A retrospective cohort study design was employed, in which 14 619 patients with T1DM were retrieved from Taiwan's National Health Insurance medical claims between 2000 and 2007. The study subjects were followed to the end of 2008, and cancer incidence was assessed. We calculated age-, sex-, and calendar year-standardized incidence ratios (SIRs) of all-cause cancer incidence and site-specific neoplasm incidence, with reference to the general population. RESULTS: Seven hundred and sixty patients were identified for all-cause cancer over 86,610 person-years, representing an incidence rate of 87.75 cases per 10,000 person-years. The incidence rate was higher in males than in female patients (109.86 vs 69.75 cases per 10,000 person-years). T1DM was associated with a significantly increased SIR of all-cause cancer (1.13; 95% confidence interval [CI], 1.05-1.22). The sex-specific SIR was significantly elevated in female patients (1.19; 95% CI, 1.07-1.33), but the SIR for male patients was insignificantly elevated (1.09; 95% CI, 0.99-1.20). Pancreatic cancer showed the greatest increase in SIR among both male and female patients with T1DM. Male patients experienced significantly increased SIRs for kidney, rectum, liver, and colon neoplasm, and significantly increased SIRs were noted for ovarian, bladder, and colon cancer in female patients. CONCLUSIONS: T1DM was associated with a 13% increase in risk of all-cause cancer incidence. Patients with T1DM should be advised to undergo cancer screening for certain types of cancer.