Concomitant consumption of marijuana, alcohol and tobacco in oral squamous cell carcinoma development and progression: recent advances and challenges

Molecular pathways in the development of HPV-induced oropharyngeal cancer

Oropharyngeal cancer, a subset of head and neck cancer, is increasingly recognized as a unique clinical entity primarily influenced by high-risk human papillomavirus (HPV) infections, particularly HPV-16. This review delves into the viral life cycle of HPV-16 and its interactions with host cells, with a specific focus on the crucial roles played by the viral oncoproteins E6 and E7. These oncoproteins drive cellular proliferation by targeting critical tumor suppressor proteins like p53 and Rb, resulting in uncontrolled cell growth and genomic instability. Furthermore, the significance of epigenetic modifications induced by HPV-16 and their implications is important for cancer progression. This comprehensive review provides valuable insights into the intricate molecular landscape of HPV-induced oropharyngeal cancer, shedding light on the development of targeted therapies and preventive strategies for this emerging global health concern. Video Abstract.

Illicit drug use and oral health

People with drug use disorders (PWDUD) have elevated prevalence of oral diseases, in particular dental caries (tooth decay), periodontal (gum) disease and xerostomia (dry mouth). When left untreated, these oral health conditions may progress and lead to tooth ache, abscesses and tooth loss, and in turn, to poor chewing functioning and digestion, dental aesthetic problems and reduced wellbeing. Illicit drug use may, per se, cause xerostomia, which in turn increases vulnerability for dental caries. However, the other main drivers of oral diseases and their progression-poor oral hygiene, frequent sugar intake and infrequent dental visits-can mainly be ascribed to the irregular lifestyle, poor economy and mental health problems that often accompany illicit drug use. Establishment of good oral health habits is essential in the dental care for PWDUD. Dental treatment is often comprehensive and challenging; because the patients may have extensive treatment needs but also difficulties adhering to preventive measures and dental appointments. An integrated care approach for PWDUD would likely benefit both their oral and general health.

Alteration of Macrophage Infiltrating Compartment: A Novel View on Oral Carcinogenesis

BACKGROUND

The mortality of oral squamous cell carcinoma (OSCC) has remained high for decades; therefore, methods for early detection of OSCC are warranted. However, in the oral cavity, various mucosal diseases may be encountered, including reactive lesions and oral potentially malignant disorders, and it is difficult to differentiate OSCC from these lesions based on both clinical and histopathological findings. It is well known that chronic inflammation contributes to oral cancer development. Macrophages are among the most common inflammatory cells in cancer stromal tissue and have various roles in cancer aggressiveness. Although the roles of macrophages in cancer development have attracted attention, only a few studies have linked macrophages to carcinogenesis, particularly, oral precancerous lesions.

SUMMARY

This review article consists of 3 parts: first, we summarize current knowledge on macrophages in human various epithelial precancerous lesions, excluding the oral cavity, to show the importance and gaps in knowledge regarding macrophages in carcinogenesis; second, we review published data related to the role of macrophages in oral carcinogenesis; finally, we present a novel view on oral carcinogenesis, focusing on crosstalk between epithelial cells and macrophages. Key Messages: The biological features of macrophages in oral carcinogenesis differ drastically depending on the anatomical compartment that they infiltrate. Focusing on the alteration of macrophage infiltrating compartment may serve as a useful novel approach for studying the role of the macrophages in oral carcinogenesis and for gaining further insight into cancer prevention and early detection.

A geospatiotemporal and causal inference epidemiological exploration of substance and cannabinoid exposure as drivers of rising US pediatric cancer rates

BACKGROUND

Age-adjusted US total pediatric cancer incidence rates (TPCIR) rose 49% 1975-2015 for unknown reasons. Prenatal cannabis exposure has been linked with several pediatric cancers which together comprise the majority of pediatric cancer types. We investigated whether cannabis use was related spatiotemporally and causally to TPCIR.

METHODS

State-based age-adjusted TPCIR data was taken from the CDC Surveillance, Epidemiology and End Results cancer database 2003-2017. Drug exposure was taken from the nationally-representative National Survey of Drug Use and Health, response rate 74.1%. Drugs included were: tobacco, alcohol, cannabis, opioid analgesics and cocaine. This was supplemented by cannabinoid concentration data from the Drug Enforcement Agency and ethnicity and median household income data from US Census.

RESULTS

TPCIR rose while all drug use nationally fell, except for cannabis which rose. TPCIR in the highest cannabis use quintile was greater than in the lowest (β-estimate = 1.31 (95%C.I. 0.82, 1.80), P = 1.80 × 10^- 7) and the time:highest two quintiles interaction was significant (β-estimate = 0.1395 (0.82, 1.80), P = 1.00 × 10^- 14). In robust inverse probability weighted additive regression models cannabis was independently associated with TPCIR (β-estimate = 9.55 (3.95, 15.15), P = 0.0016). In interactive geospatiotemporal models including all drug, ethnic and income variables cannabis use was independently significant (β-estimate = 45.67 (18.77, 72.56), P = 0.0009). In geospatial models temporally lagged to 1,2,4 and 6 years interactive terms including cannabis were significant. Cannabis interactive terms at one and two degrees of spatial lagging were significant (from β-estimate = 3954.04 (1565.01, 6343.09), P = 0.0012). The interaction between the cannabinoids THC and cannabigerol was significant at zero, 2 and 6 years lag (from β-estimate = 46.22 (30.06, 62.38), P = 2.10 × 10^- 8). Cannabis legalization was associated with higher TPCIR (β-estimate = 1.51 (0.68, 2.35), P = 0.0004) and cannabis-liberal regimes were associated with higher time:TPCIR interaction (β-estimate = 1.87 × 10^- 4, (2.9 × 10^- 5, 2.45 × 10^- 4), P = 0.0208). 33/56 minimum e-Values were > 5 and 6 were infinite.

CONCLUSION

Data confirm a close relationship across space and lagged time between cannabis and TPCIR which was robust to adjustment, supported by inverse probability weighting procedures and accompanied by high e-Values making confounding unlikely and establishing the causal relationship. Cannabis-liberal jurisdictions were associated with higher rates of TPCIR and a faster rate of TPCIR increase. Data inform the broader general consideration of cannabinoid-induced genotoxicity.

Mesoporous Silica Nanoparticles as Carriers for Therapeutic Biomolecules

The enormous versatility of mesoporous silica nanoparticles permits the creation of a large number of nanotherapeutic systems for the treatment of cancer and many other pathologies. In addition to the controlled release of small drugs, these materials allow a broad number of molecules of a very different nature and sizes. In this review, we focus on biogenic species with therapeutic abilities (proteins, peptides, nucleic acids, and glycans), as well as how nanotechnology, in particular silica-based materials, can help in establishing new and more efficient routes for their administration. Indeed, since the applicability of those combinations of mesoporous silica with bio(macro)molecules goes beyond cancer treatment, we address a classification based on the type of therapeutic action. Likewise, as illustrative content, we highlight the most typical issues and problems found in the preparation of those hybrid nanotherapeutic materials.

Cannabinoids as anticancer therapeutic agents

The recent announcement of marijuana legalization in Canada spiked many discussions about potential health benefits of Cannabis sativa. Cannabinoids are active chemical compounds produced by cannabis, and their numerous effects on the human body are primarily exerted through interactions with cannabinoid receptor types 1 (CB1) and 2 (CB2). Cannabinoids are broadly classified as endo-, phyto-, and synthetic cannabinoids. In this review, we will describe the activity of cannabinoids on the cellular level, comprehensively summarize the activity of all groups of cannabinoids on various cancers and propose several potential mechanisms of action of cannabinoids on cancer cells.

Impact of Polymorphisms in Casein Kinase 1 Epsilon and Environmental Factors in Oral Cancer Susceptibility

In Taiwan, the incidence rate of oral cancer is constantly increasing. Polymorphisms and lifestyle habits are major contributing factors to the development of oral cancer in such cases. Casein kinase 1 epsilon (CK1ε) gene expression plays a role in numerous cancers, and the knockdown of CK1ε induces tumor cell-selective cytotoxicity. The present study was designed to determine the effects of CK1ε gene polymorphisms combined with environmental carcinogens on susceptibility to developing oral squamous cell carcinoma and its clinicopathological status. Four single-nucleotide polymorphisms (SNPs) in CK1ε gene (rs135745, rs135764, rs1997644 and rs2075984) from 741 oral cancer patients and 462 healthy controls were analyzed using real-time polymerase chain reaction. Our results shown that variant types (GC) of CK1ε polymorphic rs135745 exhibited a significantly higher risk of 1.41 (95% confidence interval [CI]: 1.036-1.919) for oral cancer than did wild type alleles. Furthermore, these CK1ε gene SNPs along with betel-quid chewing and/or tobacco use further increased susceptibility to oral cancer. Moreover, variant genotypes (GC+CC) of CK1ε rs135745 were significantly associated with lymph node metastasis. These results suggested that the CK1ε gene polymorphism is associated with the clinicopathological development of oral cancer and increases individuals' susceptibility to environmental carcinogens (e.g., smoking and betel-quid chewing) in terms of developing oral cancer.

Synergistic anticancer effects of nanocarrier loaded with berberine and miR-122

We introduced polyethyleneimine (PEI)-cholesterol (PC) as a nanocarrier incorporating berberine (BER) and miR-122 for the treatment of oral squamous cell carcinoma (OSCC). BER was stabilized by incorporating PC to form ber-PC. Ber-PC was further electrostatically complexed with miR-122 to yield mr-ber-PC for the co-delivery of BER and miR-122. mr-ber-PC treatment dramatically decreased the level of invasion and migration of OSCC cells compared with single drug treatments. The present study suggested that PC could be a multifunctional nanocarrier for the co-delivery of anticancer drug BER and miR-122 to significantly increase the anticancer therapeutic effects.

The relation between gray matter volume and the use of alcohol, tobacco, cocaine and cannabis in male polysubstance users

BACKGROUND

Neuroimaging studies have demonstrated gray matter (GM) volume abnormalities in substance users. While the majority of substance users are polysubstance users, very little is known about the relation between GM volume abnormalities and polysubstance use.

METHODS

In this study we assessed the relation between GM volume, and the use of alcohol, tobacco, cocaine and cannabis as well as the total number of substances used, in a sample of 169 males: 15 non-substance users, 89 moderate drinkers, 27 moderate drinkers who also smoke tobacco, 13 moderate drinkers who also smoke tobacco and use cocaine, 10 heavy drinkers who smoke tobacco and use cocaine and 15 heavy drinkers who smoke tobacco, cannabis and use cocaine.

RESULTS

Regression analyses showed that there was a negative relation between the number of substances used and volume of the dorsal medial prefrontal cortex (mPFC) and the ventral mPFC. Without controlling for the use of other substances, the volume of the dorsal mPFC was negatively associated with the use of alcohol, tobacco, and cocaine. After controlling for the use of other substances, a negative relation was found between tobacco and cocaine and volume of the thalami and ventrolateral PFC, respectively.

CONCLUSION

These findings indicate that mPFC alterations may not be substance-specific, but rather related to the number of substances used, whereas, thalamic and ventrolateral PFC pathology is specifically associated with tobacco and cocaine use, respectively. These findings are important, as the differential alterations in GM volume may underlie different cognitive deficits associated with substance use disorders.

Synergistic therapy of chemotherapeutic drugs and MTH1 inhibitors using a pH-sensitive polymeric delivery system for oral squamous cell carcinoma

MutT homolog 1 (MTH1) is an essential sanitizer of the free nucleotide pool that prevents lethal DNA damage in cancer cells, which has been validated as an anticancer target in recent years. Small molecule TH287 potently and selectively inhibits the MTH1 protein in cells. Here, we developed an effective chemotherapeutic system for oral squamous cell carcinoma (OSCC) based on polymeric nanoparticles that achieve co-delivery of anticancer drug sodium arsenite (NaAsO₂) and MTH1 inhibitor TH287. Cationic hyperbranched poly(amine-ester) (HPAE), an amphiphilic and pH-sensitive polymer with a highly branched structure, self-assembled into nanoparticles in aqueous solution. Both NaAsO₂ and TH287 could be loaded into HPAE nanoparticles with the help of electrostatic attraction and hydrophobic interaction. The release of NaAsO₂ and TH287 from HPAE(NaAsO₂ + TH287) nanoparticles was pH-dependent. In vitro evaluation demonstrated that the HPAE(NaAsO₂ + TH287) nanoparticles rapidly entered cancer cells and released NaAsO₂ and TH287 in response to acidic intracellular environments. In comparison with NaAsO₂, TH287, HPAE(NaAsO₂) nanoparticles, HPAE(TH287) nanoparticles, and the physical mixture of HPAE(NaAsO₂) nanoparticles and TH287, the HPAE(NaAsO₂ + TH287) nanoparticles exhibited more effective inhibition of tumor cell proliferation, illustrating the synergistic effect of NaAsO₂ and TH287. The experimental results show that TH287 is likely to inhibit MTH1 in tumor cells, rendering them more sensitive to NaAsO₂.

Impact of the anatomical location, alcoholism and smoking on the prevalence of advanced oral cancer in Brazil

BACKGROUND

To evaluate the prevalence of oral cancer in Brazil according to the clinical stage, anatomical location, alcoholism and smoking.

MATERIAL AND METHODS

Data referring to 31,217 cases of oral cancer, from 2000 to 2010, were obtained from the Integrator Module of the Hospital Registry of Cancer. Inconsistent data ("non-classified" cases) was eliminated and 21,160 cases were analyzed. The frequency distribution according to clinical stage, anatomical location, alcoholism and smoking was analyzed descriptively and through a binary logistic regression model (α<0.05). The clinical stage (dependent variable) was dichotomized in early stage (I and II) or advanced stage (III and IV). The year of diagnosis, anatomical location and deleterious habits (alcoholism and smoking) were considered independent variables.

RESULTS

The most frequent characteristics were: oropharynx location (n=3856, 18.41%), clinical stage IV (n=11924, 56.09%) and combined use of alcohol and tobacco (n=19226; 61.59%). The year 2009 (p<0.01, PR = 1.162, CI-95%=1.053-1.283) and location at the base of tongue (p<0.01, PR = 2.485, CI-95% = 2.182-2.807) presented a higher prevalence ratio for advanced stage oral cancer. The combined use of alcohol and tobacco showed a higher prevalence rate for the advanced clinical stage of cancer (p<0.01, PR =1.449, CI-95%=1.382-1.520) if compared to individuals without habits, or just alcoholics.

CONCLUSIONS

Higher prevalence of advanced stage of oral cancer is related to the localization at the base of the tongue and to the concomitant use of alcohol and tobacco. Therefore, it can be suggested that all these characteristics lead to a worse prognosis of oral cancer.

Oral health assessment for users of marijuana and cocaine/crack substances

The objective of this study was to assess the oral health status of users of illicit drugs such as marijuana and cocaine/crack and compare it with individuals not using these chemical substances. Questionnaires were applied to 35 illicit drugs users to gather information on demographic status, general health, and use of drugs. Then, a clinical assessment of the oral health condition was performed to collect data on decayed, missing and filled teeth (DMFT) index, salivary flow rate (SFR), and mucosal lesions. The control group was composed of 35 non-illicit drug users. In the experimental group, 91.43% were males, 80% were smokers, and 42.85% were alcoholics. Cocaine was the most common drug used (77.15%), followed by marijuana (68.6%), and crack (51.4%). The average DMFT index was 9.8 and the SFR was reduced in 60% of subjects. Mucosal alterations were detected, but no potentially malignant disorders or oral cancer were diagnosed. Compared to control group, significantly higher values for gender (40%, p = 0.0001), smoking (22.86%) and heavy drinking (5.7%) habits (p = 0.0001), SFR (31.4%; p = 0.0308), and oral lesions (p = 0.0488) were found for the experimental group, although significantly higher values were found in the control group for DMFT index (p = 0.0148). It can be concluded that the use of illicit drugs contributed to an increased prevalence of oral mucosa lesions. In addition, a decline on SFR and a reduced DMFT index was observed for illicit drug users.

Factors associated with the high prevalence of oesophageal cancer in Western Kenya: a review

Oesophageal carcinoma (OC) is highly prevalent in Western Kenya especially among the members of the Kalenjin community who reside in the Northern and Southern areas of the Rift Valley. Previous authors have suggested potential association of environmental and genetic risk factors with this high prevalence. The environmental factors that have been suggested include contamination of food by mycotoxins and/or pesticides, consumption of traditional alcohol (locally referred to “Busaa” and “Chan’gaa”), use of fermented milk (“Mursik”), poor diet, tobacco use and genetic predisposition. The aim of this paper is to critically examine the potential contribution of each of the factors that have been postulated to be associated with the high prevalence of the disease in order to establish the most likely cause. We have done this by analyzing the trends, characteristics and behaviours that are specifically unique in the region, and corroborated this with the available literature.

From our findings, the most plausible cause of the high incidence of OC among the Kalenjin community is mycotoxins, particularly fumonisins from the food chain resulting from poor handling of cereals; particularly maize combined with traditional alcohol laced with the toxins interacting synergistically with other high-risk factors such as dietary deficiencies associated alcoholism and viral infections, especially HPV. Urgent mitigating strategies should be developed in order to minimize the levels of mycotoxins in the food chain.

Combinations of SERPINB5 gene polymorphisms and environmental factors are associated with oral cancer risks

Background

We identified rs17071138 T/C, rs3744941 C/T, and rs8089104 T/C gene polymorphisms of SERPINB5 (mammary serine protease inhibitor) that are specific to patients with oral cancer susceptibility and their clinicopathological status.

Methodology/Principal findings

In total, 1342 participants, including 601 healthy controls and 741 patients with oral cancer, were recruited for this study. Allelic discrimination of rs17071138 T/C, rs3744941 C/T, and rs8089104 T/C of the SERPINB5 gene was assessed by a real-time PCR with a TaqMan assay. We found that individuals carrying the polymorphic rs17071138 and rs8089104 are more susceptible to oral cancer (OR, 1.57; 95% CI, 1.07~2.31 and OR, 1.58; 95% CI, 1.04~2.39, respectively). Among oral cancer-related risk factor exposures, the individuals carrying the polymorphic rs17071138 had 4.26- (95% CI: 1.65~11.01; p = 0.002), 2.34- (95% CI: 1.19~4.61; p = 0.01), and 2.34-fold (95% CI: 1.38~3.96; p = 0.001) higher risks of developing oral cancer.

Conclusions

Heterozygous TC of the SERPINB5 rs17071138 polymorphism may be a factor that increases susceptibility to oral cancer. Interactions of gene-to-gene and gene-to-oral cancer-related environmental risk factors have a synergetic effect that can further enhance oral cancer development.

Nanoparticle delivery of Wnt-1 siRNA enhances photodynamic therapy by inhibiting epithelial–mesenchymal transition for oral cancer

A combination of nanoparticle delivery of Wnt-1 siRNA with photodynamic therapy was realized by inhibiting epithelial–mesenchymal transition.

Autophagy: A boon or bane in oral cancer

Autophagy is a catabolic process involving cellular recycling and is believed to play a distinct role in cell survival especially when exposed to stressors, rendering it comparable to the elixir sustaining life. It plays a significant role in various conditions like cancers, neuropathies, heart diseases, auto-immune diseases, etc. Its role in tumorigenesis and cancer therapeutics is worth exploring. Autophagy is believed to help in survival and longevity of cancer cells by buffering metabolic stress. Inhibition of autophagy in an environment of nutrient deprivation leads to cell death. Autophagy is also seen to facilitate metastasizing tumor cells in surviving the conditions of metabolic deprivation and in recovery when conditions turn favorable. Many current cancer therapies tend to inflict metabolic stress, thus autophagy inhibitors may be useful in cancer treatment. As per the adage, "excess of anything is bad", the autophagy promoters can also be exploited as beneficial tools in the fight against cancer. Another method for tumor-cell elimination can be by inducing autophagic cell death through over-stimulation. Oral cancers are becoming a leading cause of deaths worldwide. Much remains to be explored about the role autophagy plays in progression of head and neck cancers, so as to harness it in the therapeutics of these cancers. Research on autophagy is still in its infancy. There are knowledge gaps in understanding this complex process. But there is no doubt that understanding exact mechanism behind autophagy will open up new avenues in cancer therapeutics and even prevention.

Impact of Maspin Polymorphism rs2289520 G/C and Its Interaction with Gene to Gene, Alcohol Consumption Increase Susceptibility to Oral Cancer Occurrence

BACKGROUND

The purpose of this study was to identify gene polymorphisms of mammary serine protease inhibitor (Maspin) specific to patients with oral cancer susceptibility and clinicopathological status.

METHODOLOGY/PRINCIPAL FINDINGS

Three single-nucleotide polymorphisms (SNPs) of the Maspin gene from 741 patients with oral cancer and 601 non-cancer controls were analyzed by real-time PCR. The participants with G/G homozygotes or with G/C heterozygotes of Maspin rs2289520 polymorphism had a 2.07-fold (p = 0.01) and a 2.01-fold (p = 0.02) risk of developing oral cancer compared to those with C/C homozygotes. Moreover, gene-gene interaction increased the risk of oral cancer susceptibility among subjects expose to oral cancer related risk factors, including areca, alcohol, and tobacco consumption.

CONCLUSION

G allele of Maspin rs2289520 polymorphism may be a factor that increases the susceptibility to oral cancer. The interactions of gene to oral cancer-related environmental risk factors have a synergetic effect that can further enhance oral cancer development.

Alcohol consumption and corresponding factors: A novel perspective on the risk factors of esophageal cancer

Esophageal cancer is the eighth most common type of cancer in the world, and the sixth most common cause of mortality from cancer. Alcohol consumption is the major risk factor for esophageal cancer, due to the worldwide prevalence and high carcinogenicity of the ethanol metabolite. In epidemiological studies, the efficiency of alcohol intake to enhance the risk of esophageal cancer is altered by daily ethanol consumption, type of alcoholic beverages ingested, time since quitting drinking, age of drinking initiation, differences in population and subtypes of esophageal cancer. Corresponding factors, including gene polymorphisms, tobacco smoking, oral microorganisms and folate deficiency, reveal a synergistic effect in concurrent alcohol users that may lead to an increased risk of developing esophageal cancer. Consequently, esophageal cancer prevention involves multiple aspects, including quitting drinking and smoking, maintaining an adequate oral health and ingesting adequate quantities of folate, particularly in genetically high-risk populations.

Plants and other natural products used in the management of oral infections and improvement of oral health

Challenges of resistance to synthetic antimicrobials have opened new vistas in the search for natural products. This article rigorously reviews plants and other natural products used in oral health: Punica granatum L. (pomegranate), Matricaria recutita L. (chamomile), Camellia sinensis (L.) Kuntze (green tea), chewing sticks made from Diospyros mespiliformis Hochst. ex A.D.C., Diospyros lycioides Desf., and Salvadora persica L. (miswak), honey and propolis from the manuka tree (Leptospermum scoparium J.R. Forst. & G. Forst.), rhein from Rheum rhabarbarum L. (rhubarb), dried fruits of Vitis vinifera L. (raisins), essential oils, probiotics and mushrooms. Further, the review highlights plants from Africa, Asia, Brazil, Mexico, Europe, and the Middle East. Some of the plants' antimicrobial properties and chemical principles have been elucidated. While the use of natural products for oral health is prominent in resource-poor settings, antimicrobial testing is mainly conducted in the following countries (in decreasing order of magnitude): India, South Africa, Brazil, Japan, France, Egypt, Iran, Mexico, Kenya, Switzerland, Nigeria, Australia, Uganda, and the United Kingdom. While the review exposes a dire gap for more studies on clinical efficacy and toxicity, the following emerging trend was noted: basic research on plants for oral health is mainly done in Brazil, Europe and Australia. Brazil, China, India and New Zealand generally conduct value addition of natural products for fortification of toothpastes. African countries focus on bioprospecting and primary production of raw plants and other natural products with antimicrobial efficacies. The Middle East and Egypt predominantly research on plants used as chewing sticks. More research and funding are needed in the field of natural products for oral health, especially in Africa where oral diseases are fuelled by human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS).

Docetaxel-conjugated monomethoxy-poly(ethylene glycol)-b-poly(lactide) (mPEG-PLA) polymeric micelles to enhance the therapeutic efficacy in oral squamous cell carcinoma

In this study, docetaxel (DTX) was successfully conjugated to the monomethoxy-poly(ethylene glycol)-b-poly(lactide) (mPEG-PLA) polymer block via an ester linkage (DTX-PM).

Cannabinoids as therapeutic agents in cancer: current status and future implications

The pharmacological importance of cannabinoids has been in study for several years. Cannabinoids comprise of (a) the active compounds of the Cannabis sativa plant, (b) endogenous as well as (c) synthetic cannabinoids. Though cannabinoids are clinically used for anti-palliative effects, recent studies open a promising possibility as anti-cancer agents. They have been shown to possess anti-proliferative and anti-angiogenic effects in vitro as well as in vivo in different cancer models. Cannabinoids regulate key cell signaling pathways that are involved in cell survival, invasion, angiogenesis, metastasis, etc. There is more focus on CB1 and CB2, the two cannabinoid receptors which are activated by most of the cannabinoids. In this review article, we will focus on a broad range of cannabinoids, their receptor dependent and receptor independent functional roles against various cancer types with respect to growth, metastasis, energy metabolism, immune environment, stemness and future perspectives in exploring new possible therapeutic opportunities.

A cell-targeted chemotherapeutic nanomedicine strategy for oral squamous cell carcinoma therapy

Background

Oral squamous cell carcinoma (OSCC) or cancers of oral cavity is one of the most common cancers worldwide with high rate of mortality and morbidity. At present, chemotherapy is one of the most effective treatments; however it often fails to meet the requirements in the clinical therapy. In the present study, we have successfully formulated ligand-decorated cancer-targeted CDDP-loaded PLGA-PEG/NR7 nanoparticles and demonstrated the feasibility of using NR7 peptide for targeted delivery, rapid intracellular uptake, and enhanced cytotoxic effect in receptor-overexpressed OSCC cancer cells.

Results

Nanosized particles were formed and sustained release patterns were observed for PLGA/NR7 nanoparticles. Significantly higher cellular uptake was observed in HN6 OSCC cancer cells and superior anticancer effects are observed from the optimized targeted nanoparticles. Furthermore, Live/Dead assay showed a higher extent of red fluorescence was observed for the cells exposed with PLGA/NR7 than compared with non-targeted PLGA NP. The presence of the NR7-targeting moiety on the surface of PLGA carriers could allow the specific receptor-mediated internalization, enhanced cellular uptake, and higher cell killing potency. Especially, PLGA/NR7 NP exhibited a superior apoptosis effect in HN6 cancer cells with around ~45 % (early and late apoptotic stage) and ~59 % after 24 and 48 h incubation, respectively. It is apparent that the actively targeted micelles will deliver more anticancer agent to cancer cell than non-targeted one.

Conclusion

Altogether, our results show the feasibility and promise of a cell-targeted anticancer nanomedicine strategy that can be effective for the treatment of oral squamous cell carcinoma. The present work might be of great importance to the further exploration of the potential application of PLGA/NR7 in the clinically relevant animal models.

The evolving role of the endocannabinoid system in gynaecological cancer

BACKGROUND

The 'endocannabinoid system' (ECS), comprising endogenous ligands (endocannabinoids) and their regulating enzymes, together with the cannabinoid receptors, has attracted a great deal of attention because it affects not only all facets of human reproduction, from gametogenesis through to parturition and beyond, but also targets key mechanisms affecting some hallmarks of cancer. Recent evidence showing that cannabinoid receptors play a very important role in the development of malignancies outside of the reproductive organs suggests a similar role for the ECS in the establishment or continued development of gynaecological malignancy.

METHODS

Primary papers and review articles, and primary sources within these papers, up to December 2014, on the evolving role of the ECS in cancer, with a special focus on gynaecological cancers, were obtained by Medline and PubMed searches using the search terms: 'cancer', 'cannabinoid', 'endocannabinoid', 'gynaecology' and 'malignancy'. Non-English manuscripts were excluded.

RESULTS

More than 2100 sources were obtained from which only 112 were specifically important to the topic. Analysis of those articles supports a role of the ECS in gynaecological cancers but leaves many gaps in our knowledge that need to be filled. How some of the relevant receptors are activated and cause changes in cell phenotypes that progress to malignancy remains undiscovered and an area for future research. Increasing evidence suggests that malignant transformation within the female genital tract could be accompanied by deregulation of components of the ECS, acting through rather complex cannabinoid receptor-dependent and receptor-independent mechanisms.

CONCLUSIONS

The paucity of studies in this area suggests that research using animal models is needed to evaluate endocannabinoid signalling in cancer networks. Future randomized clinical studies should reveal whether endocannabinoids or their derivatives prove to be useful therapeutic targets for gynaecological and other cancers.

Sequential release of autophagy inhibitor and chemotherapeutic drug with polymeric delivery system for oral squamous cell carcinoma therapy

Autophagy inhibition is emerging as a new paradigm for efficient cancer therapy by overcoming multidrug resistance (MDR). Here, we developed an effective chemotherapeutic system for oral squamous cell carcinoma (OSCC) based on polymeric nanomicelles for codelivery of the anticancer drug doxorubicin (DOX) and the autophagy inhibitor LY294002 (LY). The hydrophobic DOX was conjugated onto a hydrophilic and pH-responsive hyperbranched polyacylhydrazone (HPAH), forming the DOX-conjugated HPAH (HPAH-DOX). Due to its amphiphilicity, HPAH-DOX self-assembled into nanomicelles in an aqueous solution and the autophagy inhibitor LY could be loaded into the HPAH-DOX micelles. The release of DOX and LY from the LY-loaded HPAH-DOX micelles was pH-dependent, whereas LY was released significantly faster than DOX at a mildly acidic condition. The in vitro evaluation demonstrated that the LY-loaded HPAH-DOX micelles could rapidly enter cancer cells and then release LY and DOX in response to an intracellular acidic environment. Compared to the HPAH-DOX micelles and the physical mixture of HPAH-DOX and LY, the LY-loaded HPAH-DOX micelles induced a higher proliferation inhibition of tumor cells, illustrating a synergistic effect of LY and DOX. The preferentially released LY inhibited the autophagy of tumor cells and made them more sensitive to the subsequent liberation of DOX. The polymeric codelivery system for programmable release of the chemotherapy drug and the autophagy inhibitor provides a new platform for combination of traditional chemotherapy and autophagy inhibition.

In vivo characterization of the novel CD44v6-targeting Fab fragment AbD15179 for molecular imaging of squamous cell carcinoma: a dual-isotope study

BACKGROUND

Patients with squamous cell carcinoma in the head and neck region (HNSCC) offer a diagnostic challenge due to difficulties to detect small tumours and metastases. Imaging methods available are not sufficient, and radio-immunodiagnostics could increase specificity and sensitivity of diagnostics. The objective of this study was to evaluate, for the first time, the in vivo properties of the radiolabelled CD44v6-targeting fragment AbD15179 and to assess its utility as a targeting agent for radio-immunodiagnostics of CD44v6-expressing tumours.

METHODS

The fully human CD44v6-targeting Fab fragment AbD15179 was labelled with 111In or 125I, as models for radionuclides suitable for imaging with SPECT or PET. Species specificity, antigen specificity and internalization properties were first assessed in vitro. In vivo specificity and biodistribution were then evaluated in tumour-bearing mice using a dual-tumour and dual-isotope setup.

RESULTS

Both species-specific and antigen-specific binding of the conjugates were demonstrated in vitro, with no detectable internalization. The in vivo studies demonstrated specific tumour binding and favourable tumour targeting properties for both conjugates, albeit with higher tumour uptake, slower tumour dissociation, higher tumour-to-blood ratio and higher CD44v6 sensitivity for the 111In-labelled fragment. In contrast, the 125I-Fab demonstrated more favourable tumour-to-organ ratios for liver, spleen and kidneys.

CONCLUSIONS

We conclude that AbD15179 efficiently targets CD44v6-expressing squamous cell carcinoma xenografts, and particularly, the 111In-Fab displayed high and specific tumour uptake. CD44v6 emerges as a suitable target for radio-immunodiagnostics, and a fully human antibody fragment such as AbD15179 can enable further clinical imaging studies.

Factors related to the formation of buccal mucosa ridging in university students

OBJECTIVE

Buccal mucosa ridging (BMR) is known as a clinical sign of clenching, which is one of the major manifestations of bruxism. However, there are few reports about the formation of BMR and no data regarding the association between BMR and factors such as malocclusion. The purpose of the current study was to investigate the relationship between BMR and factors such as the number of teeth present, gender, body mass index (BMI), occlusion and clenching habit in university students.

MATERIALS AND METHODS

A total of 2101 students (1164 males, 937 females), aged 18-29 years old, were included in the study. BMR and the number of teeth present were recorded and malocclusion was defined using a modified version of the Index of Orthodontic Treatment Need. Additional information regarding gender, clenching habit and BMI was collected via a questionnaire.

RESULTS

Forty-six per cent of the subjects had BMR and the prevalence of BMR in females was significantly higher than that of males (chi square test, p < 0.001). According to logistic regression analysis, the probability of BMR was significantly associated with female gender (OR = 1.501, 95% CI = 1.259-1.790, p < 0.001), crowding (OR = 2.102, 95% CI = 1.706-2.590, p < 0.001) and overjet (OR = 0.585, 95% CI = 0.418-0.818, p = 0.002). On the other hand, BMR was not associated with awareness of clenching habit and BMI.

CONCLUSIONS

Gender, crowding and overjet were related to the formation of BMR in university students. When evaluating BMR as a clinical sign of clenching, one might have to take factors such as gender and crowding into consideration.

Impact of interleukin-18 polymorphisms -607A/C and -137G/C on oral cancer occurrence and clinical progression

BACKGROUND

The purpose of this study was to identify gene polymorphisms of interleukin-18 (IL-18) -607A/C and -137G/C specific to patients with oral cancer susceptibility and clinicopathological status.

METHODOLOGY AND PRINCIPAL FINDINGS

A total of 1,126 participants, including 559 healthy people and 567 patients with oral cancer, were recruited for this study. Allelic discrimination of -607A/C (rs1946518) and -137G/C (rs187238) polymorphisms of the IL-18 gene was assessed by a real-time PCR with the TaqMan assay. There was no significant association between IL-18 -607A/C polymorphism and oral cancer risk. However, among alcohol consumers, people with A/A homozygotes of IL-18 -607A/C polymorphism had a 2.38-fold (95% CI=1.17-4.86; p=0.01) increased risk of developing oral cancer compared with those with C/C homozygotes. The participants with G/C heterozygotes of IL-18 -137 polymorphism had a 1.64-fold (95% CI: 1.08-2.48; p=0.02) increased risk of developing oral cancer compared with those with G/G wild type homozygotes. Both sets of statistics were determined after adjusting for confounding factors. Among people who had exposure to oral cancer-related environmental risk factors such as areca, alcohol, and tobacco consumption, the adjusted odd ratios and 95% confidence intervals were increased to a 2.02-fold (95% CI=1.01-4.04; p=0.04), 4.04 (95% CI=1.65-9.87; p=0.002) and a 1.66-fold (95% CI=1.00-2.84; p=0.05) risk of developing oral cancer. However, patients with G/C alleles of IL-18 -137 were correlated with a lower clinical stage (AOR=0.59; 95% CI=0.39-0.89; p=0.01), smaller tumor size (AOR=0.56; 95% CI=0.35-0.87; p=0.01), and non-lymph node metastasis (AOR=0.51; 95% CI=0.32-0.80; p=0.003).

CONCLUSION

IL-18 -137 G/C gene polymorphism may be a factor that increases the susceptibility to oral cancer, as well as a protective factor for oral cancer progression. The interactions of gene to oral cancer-related environmental risk factors have a synergetic effect that can further enhance oral cancer development.

Marijuana: current concepts(†)

Marijuana (cannabis) remains a controversial drug in the twenty-first century. This paper considers current research on use of Cannabis sativa and its constituents such as the cannabinoids. Topics reviewed include prevalence of cannabis (pot) use, other drugs consumed with pot, the endocannabinoid system, use of medicinal marijuana, medical adverse effects of cannabis, and psychiatric adverse effects of cannabis use. Treatment of cannabis withdrawal and dependence is difficult and remains mainly based on psychological therapy; current research on pharmacologic management of problems related to cannabis consumption is also considered. The potential role of specific cannabinoids for medical benefit will be revealed as the twenty-first century matures. However, potential dangerous adverse effects from smoking marijuana are well known and should be clearly taught to a public that is often confused by a media-driven, though false message and promise of benign pot consumption.

Alcohol and tobacco misuse: Reducing aerodigestive cancer risk

Significant concerns over the health, social and economic burdens of the two most common, and frequently co-misused drugs of abuse, alcohol and tobacco, has encouraged focused but separate health promotion and disease prevention policies. However, this separation of focus means that while individuals who present with alcohol-related problems are increasingly supported to attain and maintain abstinence from alcohol they are not routinely assisted to refrain from smoking. This is tragically inopportune as alcohol and tobacco have an established “synergistic” effect on aerodigestive cancer risk. Moreover, even when patients successfully tackle their alcohol problems they remain at increased risk for developing these cancers, especially if they continue to smoke. A case series is presented together with a discussion on how service provision for co-misuse could be improved to obviate aerodigestive cancer risk. Given the prevalence of alcohol and tobacco use in the United Kingdom, these observations may have far reaching implications for the individual, health provider(s) and wider society.

Cannabinoid receptor-2 immunoreactivity is associated with survival in squamous cell carcinoma of the head and neck

The prediction of progression of individual tumours, prognosis, and survival in squamous cell carcinoma (SCC) of the head and neck is difficult. Cannabinoid-1 (CB1) and cannabinoid-2 (CB2) receptor expression is related to survival in several types of cancer, and the aim of this study was to find out whether the expression of CB1 and CB2 receptors is associated with survival in primary SCC of the head and neck. We made immunohistochemical analyses of the cannabinoid receptors on tissue arrays from 240 patients with the disease. Receptor immunoreactivity was classified as none, weak, moderate, or strong staining. Overall survival and disease-specific survival were plotted using Kaplan-Meier survival curves. A multivariate Cox proportional hazard model was created with all the relevant clinical and pathological features. Strong immunoreactivity of the CB2 receptor was significantly associated with reduced disease-specific survival (p=0.007). Cox-proportional hazard ratio (HR) showed that CB2 receptor immunoreactivity contributed to the prediction of survival (HR 3.6, 95% CI 1.5-8.7, p=0.004). Depth of invasion (HR 2.2, 95% CI 1.2-4.2, p=0.01) and vascular invasion (HR 2.5, 95% CI 1.4-4.5, p=0.001) were also associated with survival.