Genetic linkage analysis of head and neck cancer in a Spanish family

OBJECTIVES

To describe the genetic variants that may be associated with the development of head and neck cancer (HNC) and functionally validating the molecular implications.

MATERIALS AND METHODS

A prospective observational study was carried out on a family of 3 generations in which 3 members had developed HNC. Peripheral blood sample was taken in a routine procedure for exome sequencing in one relative and genotyping in the remaining twelve relatives. For the functional analysis all-trans retinoic acid (atRA) was extracted from saliva and serum and measured using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The presence of HPV-DNA.

RESULTS

None of the patients smoked or consumed alcohol. The presence of HPV DNA was not detected in any of the biopsied samples. A total amount of 6 members out of 13 (46.15%) carried out the same mutation of CYP26B1 (2p13.2; G>T). The mean plasma concentration of atRA was 3.3109 ± 1.4791 pg/mL for the study family and 4.7370 ± 1.5992 pg/mL for the controls (p = 0.042).

CONCLUSION

Lower levels of atRA were confirmed in the study family, which may open the way to the possible relationship between the polymorphism CYP26B1 (2p13.2; G>T) and HNC.

Genetic and epigenetic alterations in DNA repair genes and treatment outcome of chemoradiotherapy in cervical cancer

Cervical cancer (CaCx) is the deadliest malignancy among women which is caused by human papillomavirus (HPV) and anthro-demographical/clinicopathological factors. HPV oncoproteins E6 and E7 target p53 and RB (retinoblastoma) protein degradation, Ataxia telangiectasia mutated (ATM), ATM-RAD3-related (ATR) inactivation and subsequent impairment of non-homologous end joining (NHEJ), homologous recombination, and base excision repair pathways. There is also an accumulation of genetic and epigenetic alterations in Tumor Growth Suppressors (TGS), oncogenes, and DNA repair genes leading to increased genome instability and CaCx development. These alterations might be responsible for differential clinical response to Cisplatin-based chemoradiotherapy (CRT) in patients. This review explores HPV-mediated DNA damage as a risk factor in CaCx development, the mechanistic role of genetic and epigenetic alterations in DNA repair genes and their association with CRT and outcome, It also explores new possibilities for the development of genetic and epigenetic-based biomarkers for diagnostic, prognostic, and molecular therapeutic interventions.

Impact of tobacco smoking on oral cancer genetics-A next-generation sequencing perspective

This study identified a total of 28 genetic loci (comprising 31 genes), which were found to be altered in oral cancer patients having a habit of tobacco smoking. Three loci, that is, 17p13.1 (TP53), 9p21.3 (CDKN2A), and 9q34.3 (NOTCH1) were found to be modified and common in three records whereas one locus, that is, 3q26.32 (PIK3CA) was found to be modified and common in two records. This study suggests that oral cancer patients should be categorized into different subgroups based on (i) genetic signatures, and (ii) smoking status, then the treatment strategies for each group should be precisely defined.

Global, regional, and national burden and quality of care index (QCI) of lip and oral cavity cancer: a systematic analysis of the Global Burden of Disease Study 1990-2017

BACKGROUND

To measure the quality of care for lip and oral cavity cancer worldwide using the data from the Global Burden of Disease (GBD) Study 2017.

METHODS

After devising four main indices of quality of care for lip and oral cavity cancer using GBD 2017 study's measures, including prevalence, incidence, years of life lost, years lived with disability, and disability-adjusted life years, we utilised principal component analysis (PCA) to determine a component that bears the most proportion of info among the others. This component of the PCA was considered as the Quality-of-Care Index (QCI) for lip and oral cavity cancer. The QCI score was then reported in both men and women worldwide and different countries based on the socio-demographic index (SDI) and World Bank classifications.

RESULTS

Between 1990 and 2017, care quality continuously increased globally (from 53.7 to 59.6). In 1990, QCI was higher for men (53.5 for men compared with 50.8 for women), and in 2017 QCI increased for both men and women, albeit a slightly higher rise for women (57.2 for men compared with 59.9 for women). During the same period, age-standardised QCI for lip and oral cavity cancer increased in all regions (classified by SDI and World Bank). Globally, the highest QCI scores were observed in the elderly age group, whereas the least were in the adult age group. Five countries with the least amount of QCIs were all African. In contrast, North American countries, West European countries and Australia had the highest indices.

CONCLUSION

The quality of care for lip and oral cavity cancer showed a rise from 1990 to 2017, a promising outcome that supports patient-oriented and preventive treatment policies previously advised in the literature. However, not all countries enjoyed such an increase in the QCI to the same extent. This alarming finding could imply a necessary need for better access to high-quality treatments for lip and oral cavity cancer, especially in central African countries and Afghanistan. More policies with a preventive approach and paying more heed to the early diagnosis, broad insurance coverage, and effective screening programs are recommended worldwide. More focus should also be given to the adulthood age group as they had the least QCI scores globally.

Overview of oral cavity squamous cell carcinoma: Risk factors, mechanisms, and diagnostics

Oral cavity squamous cell carcinoma (OCSCC) is the most common malignancy of the oral cavity. The substantial risk factors for OCSCC are the consumption of tobacco products, alcohol, betel quid, areca nut, and genetic alteration. However, technological advancements have occurred in treatment, but the survival decreases with late diagnosis; therefore, new methods are continuously being investigated for treatment. In addition, the rate of secondary tumor formation is 3-7% yearly, which is incomparable to other malignancies and can lead to the disease reoccurrence. Oral cavity cancer (OCC) arises from genetic alterations, and a complete understanding of the molecular mechanism involved in OCC is essential to develop targeted treatments. This review aims to update the researcher on oral cavity cancer, risk factors, genetic alterations, molecular mechanism, classification, diagnostic approaches, and treatment.

Is There a Genetic Predisposition to Postoperative Adhesion Development?

Adhesions are permanent fibrovascular bands between peritoneal surfaces, which develop following virtually all body cavity surgeries. The susceptibility to develop, and the severity, of adhesions following intra-abdominal surgery varies within and between individuals, suggesting that heritable factors influence adhesion development. In this manuscript, we discuss the pathophysiology of adhesion development from the perspective of genetic susceptibility. We restrict our discussion to genes and single-nucleotide polymorphisms (SNPs) that are specifically involved in, or that cause modification of, the adhesion development process. We performed a literature search using the PubMed database for all relevant English language articles up to March 2020 (n = 186). We identified and carefully reviewed all relevant articles addressing genetic mutations or single-nucleotide polymorphisms (SNPs) that impact the risk for adhesion development. We also reviewed references from these articles for additional information. We found several reported SNPs, genetic mutations, and upregulation of messenger RNAs that directly or indirectly increase the propensity for postoperative adhesion development, namely in genes for transforming growth factor beta, vascular endothelial growth factor, interferon-gamma, matrix metalloproteinase, plasminogen activator inhibitor-1, and the interleukins. An understanding of genetic variants could provide insight into the pathophysiology of adhesion development. The information presented in this review contributes to a greater understanding of adhesion development at the genetic level and may allow modification of these genetic risks, which may subsequently guide management in preventing and treating this challenging complication of abdominal surgery. In particular, the information could help identify patients at greater risk for adhesion development, which would make them candidates for anti-adhesion prophylaxis. Currently, agents to reduce postoperative adhesion development exist, and in the future, development of agents, which specifically target individual genetic profile, would be more specific in preventing intraperitoneal adhesion development.

Advanced diagnostic aids for oral cancer

Oral cancer, a universal malady, has become a stumbling block over the years due to its significant morbidity and mortality rates. The greater morbidity associated with this deadly disease is attributed to delay in its diagnosis / its presentation in advanced stage. Being multifactorial, Oral squamous cell carcinoma (OSCC) is the outcome of genetic and epigenetic instability. However, in many instances, oral cancer is preceded by precursor lesions named as oral potentially malignant disorders (OPMDs), the early detection of which makes it beneficial for patients with the possible increase in the productive longevity. Many diagnostic tools / aids have been explored with the aim of early detection of oral precancer and cancer. The basic chair-side procedures or relatively advanced aids come with a set of limitations along with subjectivity as one of the setbacks. The advent and exploitation of molecular techniques in the field of health diagnostics, is demanding the molecular typing of the OPMDs and also of oral cancer. The saga of various diagnostic aids for OSCC has witnessed the so-called latest trends such as lab-on-chip, microfluidics, nano diagnostics, liquid biopsy, omics technology and synthetic biology in early detection of oral precancer and cancer. Oral cancer being multifactorial in origin with the chief participation of altered genetics and epigenetics would demand high-end diagnostics for designing personalized therapy. Hence, the present paper highlights the role of various advanced diagnostic aids including 'omics' technology and synthetic biology in oral precancer and cancer.

TheXRCC4rs1805377 polymorphism is not associated with the risk of cancer: An updated meta-analysis

Objectives

A growing number of studies have reported that genes involved in the repair of DNA double-strand breaks might be cancer-susceptibility genes. The x-ray cross-complementing group 4 gene ( XRCC4) encodes a protein that functions in the repair of DNA double-strand breaks, and this meta-analysis aimed to investigate the relationship between the XRCC4 rs1805377 polymorphism and cancer occurrence.

Methods

We retrieved case–control studies that met the inclusion criteria from PubMed, Web of Science, Embase, and China National Knowledge Infrastructure databases. Associations between rs1805377 and cancer risk were evaluated by odds ratios (ORs) using a random effects model and 95% confidence intervals (CIs) as well as sensitivity and subgroup analyses.

Results

After inclusion criteria were met, the meta-analysis involved 24 studies that included 9,633 cancer patients and 10,544 healthy controls. No significant association was found between rs1805377 and the risk of cancer (pooled OR = 1.107; 95% CI = 0.955–1.284) in the dominant genetic model. Similarly, no significant association was observed in the subgroup analysis.

Conclusions

Through this meta-analysis, we found no association between the rs1805377 polymorphism and cancer occurrence. This may provide useful information for relevant future studies into the etiology of cancer.

World Workshop on Oral Medicine VII: Functional pathways involving differentially expressed lncRNAs in oral squamous cell carcinoma

Long non-coding RNAs (lncRNA) modulate gene expression at the epigenetic, transcriptional and post-transcriptional levels and are involved in tumorigenesis. They can form complex secondary and tertiary structures and have been shown to act as precursors, enhancers, reservoirs and decoys in the complex endogenous RNA network. They were first reported in relation to oral squamous cell carcinoma (OSCC) in 2013. Here, we summarise the functional roles and pathways of the most commonly studied lncRNAs in OSCC. Existing research demonstrates the involvement of lncRNA within pivotal pathways leading to the development and spread of OSCC, including interactions with key cancer-associated microRNAs such as miR-21. The number of studies on lncRNA and OSCC remains limited in this new field. As evidence grows, the tissue-specific expression patterns of lncRNAs should further advance our understanding of the altered regulatory networks in OSCC and possibly reveal new biomarkers and therapeutic targets.

Tumor-infiltrating lymphocyte-derived MLL2 independently predicts disease-free survival for patients with early-stage oral squamous cell carcinoma

BACKGROUND

MLL2 (mixed-lineage leukemia 2) is recognized as an essential role in regulating histone 3 lysine 4 tri-methylation (H3K4me3) in mammalian cells. It is frequently mutated to promote developmental diseases and tumor initiation. However, the expression pattern of MLL2 and its clinical significance for patients with early-stage oral squamous cell carcinoma (OSCC) remain totally unknown.

METHODS

Eighty-five samples of primary early-stage OSCC were enrolled in this retrospective study, and immunohistochemistry (IHC) was performed to detect the spatial pattern of MLL2. The diagnostic and prognostic value of MLL2 were assessed.

RESULTS

MLL2 was widely expressed in tumor cells (TCs), fibroblast-like cells (FLCs), and tumor-infiltrating lymphocytes (TILs), both in tumor center and invasive tumor front, and showed no distributive heterogeneity. Moreover, regardless of cell types and microlocalization, patients with high expressed MLL2 had increased depth invasion of tumor (DOI). Besides, upregulation of MLL2^TC and MLL2^TIL in tumor center were both associated with poor differentiation, but showed no correlation with tumor growth with comparable Ki-67 levels. Prognostic analysis indicated that early-stage OSCC patients with enhanced MLL2^TIL in invasive tumor front were susceptible to occur postoperative metastasis and recurrence. Indeed, patients with higher expressed MLL2^TIL showed shorter overall survival (OS) and disease-free survival (DFS), and MLL2^TIL in invasive tumor front was an independent risk factor of DFS.

CONCLUSION

TIL-derived MLL2 in invasive tumor front was an independent prognostic factor of DFS for early-stage OSCC patients.

Rapid in-field failures following adjuvant radiation for buccal squamous cell carcinoma

OBJECTIVES/HYPOTHESIS

Squamous cell carcinoma originating in the buccal mucosa and retromolar trigone (RMT) have historically poor outcomes. Difficulties in discriminating tumor origin often result in these subsites being combined in surgical and pathological reports. We aimed to determine if making this anatomical distinction has implications for treatment design and clinical outcomes.

STUDY DESIGN

Retrospective case series.

METHODS

We identified 27 tumors from either the buccal mucosa patients or RMT patients who underwent surgery followed by radiation. For patients who developed a local failure, we fused the pretreatment imaging, simulation computed tomography, and follow-up imaging to determine the location of failures relative to the radiation field. We calculated the 2-year locoregional control and 2-year disease-free survival.

RESULTS

The median time from surgery to radiation was 50 days (range, 32-133 days). The 2-year locoregional control for buccal mucosa versus RMT, respectively, were 35.9% versus 68.4% (P = .252). The 2-year disease-free survival rates were 32.7% versus 68.4%, respectively (P = .196). The median times to failure were 12.00 months (range, 4.9-115.0 months) versus 18.5 months (range, 4.5-61.0 months), respectively. All buccal mucosa failures occurred within the high-dose planning target volume, with a median dose of 60 Gy within the failure region. Following locoregional failure, 10 of the 12 patients have died, with a median time from local failure to death of 3.6 months (range, 1-17.6 months).

CONCLUSIONS

Squamous cell carcinomas of the buccal mucosa appear to have a poor prognosis characterized by rapid in-field failure. Therefore, differentiating tumor origin may be important for prognostication and treatment.

LEVEL OF EVIDENCE

3 Laryngoscope, 130:413-417, 2020.

Comprehensive Analysis of the Association Between the rs1138272 Polymorphism of the GSTP1 Gene and Cancer Susceptibility

Background: We obtained conflicting results regarding the relationship between the genetic role of the rs1138272 C/T polymorphism of the GSTP1 (Glutathione S-Transferase pi) gene and the risk of various cancers.

Methods: Using the presently available data, a meta-analysis was conducted to comprehensively evaluate the genetic relationship between the GSTP1 rs1138272 polymorphism and cancer susceptibility.

Results: A total of 43 studies including 15,688 cases and 17,143 controls were recruited into our quantitative synthesis. In the overall population, we observed an increased risk of overall cancer cases, compared with unrelated controls, in the genetic models of allele T vs. allele C (P-association = 0.007, OR = 1.17), carrier T vs. carrier C (P-association = 0.035, OR = 1.11), TT vs. CC (P-association = 0.002, OR = 1.45), TT vs. CC+CT (P-association = 0.009, OR = 1.42), and CT+TT vs. CC (P-association = 0.027, OR = 1.13). We detected similar positive results within the Asian population. Additionally, there was a significant increase in the incidence of cancer for Africans under all genetic models (all P-association < 0.05, OR > 1). When targeting the Caucasian population, we detected a positive association with the TT vs. CC and TT vs. CC+CT models in the “Colorectal cancer” (P-association < 0.05, OR < 1) and “Head and neck cancer” (P-association < 0.05, OR > 1) subgroups. For the “Lung cancer” subgroup, we observed a slightly increased risk in Caucasians under the models of allele T vs. allele C, carrier T vs. carrier C, CT vs. CC, and CT+TT vs. CC (P-association < 0.05, OR > 1).

Conclusion: The TT genotype of the GSTP1 rs1138272 polymorphism is likely related to the susceptibility to overall cancer in the Asian and African populations and, specifically, “Colorectal” and “Head and neck” cancers in the Caucasian population. In addition, the CT genotype of the GSTP1 rs1138272 polymorphism may be linked to the risk of lung cancer in Caucasians. Additional evidence is required to confirm this conclusion.

DKK3 knockdown confers negative effects on the malignant potency of head and neck squamous cell carcinoma cells via the PI3K/Akt and MAPK signaling pathways

Dickkopf‑related protein 3 (DKK3), which is a member of the Dickkopf WNT signaling pathway inhibitor family, is considered to be a tumor suppressor, due to its reduced expression in cancer cells and its ability to induce apoptosis when overexpressed by adenovirus. However, our previous study demonstrated alternative functions for DKK3 in head and neck squamous cell carcinoma (HNSCC). Our study reported that DKK3 expression was predominantly upregulated in HNSCC cell lines and tissue samples, and its expression was significantly correlated with poor prognosis. Furthermore, DKK3 overexpression in HNSCC cells significantly increased cancer cell proliferation, migration, invasion and in vivo tumor growth. These data have led to the hypothesis that DKK3 may exert oncogenic functions and may increase the malignant properties of HNSCC. The present study established a stable DKK3 knockdown cell line (HSC‑3 shDKK3) using lentivirus‑mediated short hairpin RNA, and assessed its effects on cancer cell behavior using MTT, migration and invasion assays. In addition, its effects on in vivo tumor growth were assessed using a xenograft model. Furthermore, the molecular mechanisms underlying the effects of DKK3 knockdown were investigated by microarray analysis, pathway analysis and western blotting. Compared with control cells, HSC‑3 shDKK3 cells exhibited significantly reduced proliferation, migration and invasion, and formed significantly smaller tumor masses when subcutaneously transplanted into nude mice. In addition, in HSC‑3 shDKK3 cells, the expression levels of phosphorylated (p)‑protein kinase B (Akt) (Ser473), p‑phosphoinositide 3‑kinase (PI3K) p85 (Tyr467), p‑PI3K p55 (Try199), p‑3‑phosphoinositide‑dependent protein kinase‑1 (PDK1) (Ser241) and total p38 mitogen‑activated protein kinase (MAPK) were reduced. Furthermore, phosphorylation of mechanistic target of rapamycin (mTOR) (Ser2448) was slightly decreased in HSC‑3 shDKK3 cells, which may be due to the increased expression of DEP domain‑containing mTOR‑interacting protein. Conversely, DKK3 overexpression in HSC‑3 shDKK3 cells rescued cellular proliferation, migration and invasion. With regards to expression levels, p‑PI3K and p‑PDK1 expression was not altered, whereas mTOR and p‑p38 MAPK expression was elevated. These data supported the hypothesis and indicated that DKK3 may contribute to the malignant phenotype of HNSCC cells via the PI3K/Akt/mTOR and MAPK signaling pathways.

Biomarkers: paving stones on the road towards the personalized precision medicine for oral squamous cell carcinoma

Traditional therapeutics have encountered a bottleneck caused by diagnosis delay and subjective and unreliable assessment. Biomarkers can overcome this bottleneck and guide us toward personalized precision medicine for oral squamous cell carcinoma. To achieve this, it is important to efficiently and accurately screen out specific biomarkers from among the huge number of molecules. Progress in omics-based high-throughput technology has laid a solid foundation for biomarker discovery. With credible and systemic biomarker models, more precise and personalized diagnosis and assessment would be achieved and patients would be more likely to be cured and have a higher quality of life. However, this is not straightforward owing to the complexity of molecules involved in tumorigenesis. In this context, there is a need to focus on tumor heterogeneity and homogeneity, which are discussed in detail. In this review, we aim to provide an understanding of biomarker discovery and application for precision medicine of oral squamous cell carcinoma, and have a strong belief that biomarker will pave the road toward future precision medicine.