Epidermal growth factor receptor inhibitors as potential anticancer agents: An update of recent progress

Synthesis, Anticancer Activity, and Docking Studies of Novel Hydroquinone-Chalcone-Pyrazoline Hybrid Derivatives

A novel series of antitumor hybrids was synthesized using 1,4-benzohydroquinone and chalcone, furane, or pyrazoline scaffolds. This were achieved through isosteric substitution of the aryl group of the chalcone β-carbon with the furanyl moiety and structural modification of the α,β-unsaturated carbonyl system. The potential antitumor activity of these hybrids was evaluated in vivo on MCF-7 breast adenocarcinoma and HT-29 colorectal carcinoma cells, demonstrating cytotoxic activity with IC50 values ranging from 28.8 to 124.6 µM. The incorporation of furan and pyrazoline groups significantly enhanced antiproliferative properties compared to their analogues and precursors (VII-X), which were inactive against both neoplastic cell lines. Compounds 4, 5, and 6 exhibited enhanced cytotoxicity against both cell lines, whereas compound 8 showed higher cytotoxic activity against HT-29 cells. Molecular docking studies revealed superior free-energy values (ΔGbin) for carcinogenic pathway-involved kinase proteins, with our in silico data suggesting that these derivatives could be promising chemotherapeutic agents targeting kinase pathways. Among all the synthesized PIBHQ compounds, derivatives 7 and 8 exhibited the best drug-likeness properties, with values of 0.53 and 0.83, respectively. ADME results collectively suggest that most of these compounds hold promise as potential candidates for preclinical assays.

Compounds Consisting of Quinazoline, Ibuprofen, and Amino Acids with Cytotoxic and Anti-Inflammatory Effects

In this research work, a series of 16 quinazoline derivatives bearing ibuprofen and an amino acid were designed as inhibitors of epidermal growth factor receptor tyrosine kinase domain (EGFR-TKD) and cyclooxygenase-2 (COX-2) with the intention of presenting dual action in their biological behavior. The designed compounds were synthesized and assessed for cytotoxicity on epithelial cancer cells lines (AGS, A-431, MCF-7, MDA-MB-231) and epithelial non-tumorigenic cell line (HaCaT). From this evaluation, derivative 6 was observed to exhibit higher cytotoxic potency (IC50) than gefitinib (reference drug) on three cancer cell lines (0.034 μM in A-431, 2.67 μM in MCF-7, and 3.64 μM in AGS) without showing activity on the non-tumorigenic cell line (>100 μM). Furthermore, assessment of EGFR-TKD inhibition by 6 showed a discreet difference compared to gefitinib. Additionally, 6 was used to conduct an in vivo anti-inflammatory assay using the 12-O-tetradecanoylphorbol-3-acetate (TPA) method, and it was shown to be 5 times more potent than ibuprofen. Molecular dynamics studies of EGFR-TKD revealed interactions between compound 6 and M793. On the other hand, one significant interaction was observed for COX-2, involving S531. The RMSD graph indicated that the ligand remained stable in 50 ns.

Human epidermal growth receptor polymorphisms (HER1-rs11543848 and HER2-rs1136201) exhibited significant association with breast cancer risk in Pashtun population of Khyber Pakhtunkhwa, Pakistan

Background and Aims

Breast cancer is the most common type of cancer in women. The genetic polymorphism in HER (HER1-rs11543848 and HER2-rs1136201) were found to be associated with breast cancer risk in different ethnicities worldwide with inconsistent results. The aim of this research study was to evaluate the association of HER1-rs11543848 and HER2-rs1136201 polymorphisms as a risk of breast cancer in Pashtun population of Khyber Pakhtunkhwa, Pakistan.

Methods

A total of 314 women including 164 breast cancer patients and 150 age and gender-matched healthy controls were enrolled from June 2021 to May 2022. All the samples were subjected to DNA extraction followed by Tetra-ARMS-PCR for genotyping and gel electrophoresis.

Results

Our results indicated that HER1-rs11543848 risk allele A (p = 0.0001) and heterozygous genotype GA (p = 0.0001) displayed highly significant association with breast cancer, while the homozygous mutant genotype AA indicated association but nonsignificant results (odds ratio [OR] = 2.637, 95% confidence interval [CI] = 1.2258-5.6756, p = 0.0833). Similarly, the HER2-rs1136201 risk allele G (p = 0.0023), the heterozygous genotype AG (p = 0.0530) and homozygous mutant genotype GG showed significant association (OR = 2.5946, 95% CI = 0.9876-6.8165, p = 0.0530) with breast cancer risk. Both the SNPs presented a higher but nonsignificant risk of breast cancer in postmenopausal women (OR = 2.242, p = 0.08 and OR = 2.009, p = 0.06). However, both the SNPs showed significant association (p < 0.005) with family history, metastasis, stage, luminal B, and TNBC.

Conclusion

In conclusion, HER1-rs11543848 and HER2-rs1136201 polymorphisms are significantly associated with the higher risk of breast cancer in Pashtun population of Khyber Pakhtunkhwa, Pakistan. These findings advocate for further exploration with larger datasets, offering promising avenues for personalized approaches in breast cancer research and potentially enhancing clinical practices for better risk assessment and targeted management strategies.

Preclinical Anticipation of On- and Off-Target Resistance Mechanisms to Anti-Cancer Drugs: A Systematic Review

The advent of targeted therapies has led to tremendous improvements in treatment options and their outcomes in the field of oncology. Yet, many cancers outsmart precision drugs by developing on-target or off-target resistance mechanisms. Gaining the ability to resist treatment is the rule rather than the exception in tumors, and it remains a major healthcare challenge to achieve long-lasting remission in most cancer patients. Here, we discuss emerging strategies that take advantage of innovative high-throughput screening technologies to anticipate on- and off-target resistance mechanisms before they occur in treated cancer patients. We divide the methods into non-systematic approaches, such as random mutagenesis or long-term drug treatment, and systematic approaches, relying on the clustered regularly interspaced short palindromic repeats (CRISPR) system, saturated mutagenesis, or computational methods. All these new developments, especially genome-wide CRISPR-based screening platforms, have significantly accelerated the processes for identification of the mechanisms responsible for cancer drug resistance and opened up new avenues for future treatments.

Quinazoline-based VEGFR-2 inhibitors as potential anti-angiogenic agents: A contemporary perspective of SAR and molecular docking studies

Angiogenesis, the formation of new blood vessels from the existing vasculature, is pivotal in the migration, growth, and differentiation of endothelial cells in normal physiological conditions. In various types of tumour microenvironments, dysregulated angiogenesis plays a crucial role in supplying oxygen and nutrients to cancerous cells, leading to tumour size growth. VEGFR-2 tyrosine kinase has been extensively studied as a critical regulator of angiogenesis; thus, inhibition of VEGFR-2 has been widely used for cancer treatments in recent years. Quinazoline nucleus is a privileged and versatile scaffold with a broad range of pharmacological activity, especially in the field of tyrosine kinase inhibitors with more than twenty small molecule inhibitors approved by the US Food and Drug Administration in the last two decades. As of now, the U.S. FDA has approved eleven small chemical inhibitors of VEGFR-2 for various types of malignancies, with a prime example being vandetanib, a quinazoline derivative, which is a multi targeted kinase inhibitor used for the treatment of late-stage medullary thyroid cancer. Despite of prosperous discovery and development of VEGFR-2 down regulator drugs, there still exists limitations in clinical efficacy, adverse effects, a high rate of clinical discontinuation and drug resistance. Therefore, there is an urgent need for the design and synthesis of more selective and effective inhibitors to tackle these challenges. Through the gathering of this review, we have strived to broaden the extent of our view over the entire scope of quinazoline-based VEGFR-2 inhibitors. Herein, we give an overview of the importance and advancement status of reported structures, highlighting the SAR, biological evaluations and their binding modes.

Repurposing EGFR Inhibitors for Oral Cancer Pain and Opioid Tolerance

Oral cancer pain remains a significant public health concern. Despite the development of improved treatments, pain continues to be a debilitating clinical feature of the disease, leading to reduced oral mobility and diminished quality of life. Opioids are the gold standard treatment for moderate-to-severe oral cancer pain; however, chronic opioid administration leads to hyperalgesia, tolerance, and dependence. The aim of this review is to present accumulating evidence that epidermal growth factor receptor (EGFR) signaling, often dysregulated in cancer, is also an emerging signaling pathway critically involved in pain and opioid tolerance. We presented preclinical and clinical data to demonstrate how repurposing EGFR inhibitors typically used for cancer treatment could be an effective pharmacological strategy to treat oral cancer pain and to prevent or delay the development of opioid tolerance. We also propose that EGFR interaction with the µ-opioid receptor and glutamate N-methyl-D-aspartate receptor could be two novel downstream mechanisms contributing to pain and morphine tolerance. Most data presented here support that repurposing EGFR inhibitors as non-opioid analgesics in oral cancer pain is promising and warrants further research.

A novel EGFR inhibitor acts as potent tool for hypoxia-activated prodrug systems and exerts strong synergistic activity with VEGFR inhibition in vitro and in vivo

Small-molecule EGFR inhibitors have distinctly improved the overall survival especially in EGFR-mutated lung cancer. However, their use is often limited by severe adverse effects and rapid resistance development. To overcome these limitations, a hypoxia-activatable Co(III)-based prodrug (KP2334) was recently synthesized releasing the new EGFR inhibitor KP2187 in a highly tumor-specific manner only in hypoxic areas of the tumor. However, the chemical modifications in KP2187 necessary for cobalt chelation could potentially interfere with its EGFR-binding ability. Consequently, in this study, the biological activity and EGFR inhibition potential of KP2187 was compared to clinically approved EGFR inhibitors. In general, the activity as well as EGFR binding (shown in docking studies) was very similar to erlotinib and gefitinib (while other EGFR-inhibitory drugs behaved different) indicating no interference of the chelating moiety with the EGFR binding. Moreover, KP2187 significantly inhibited cancer cell proliferation as well as EGFR pathway activation in vitro and in vivo. Finally, KP2187 proved to be highly synergistic with VEGFR inhibitors such as sunitinib. This indicates that KP2187-releasing hypoxia-activated prodrug systems are promising candidates to overcome the clinically observed enhanced toxicity of EGFR-VEGFR inhibitor combination therapies.

Personalization of Radiation Therapy in the Primary Treatment of Malignant Epidural Spinal Cord Compression (MESCC)

"True" malignant epidural spinal cord compression (MESCC) is used here to describe a lesion compressing of infiltrating the spinal cord associated with neurologic deficits. Radiotherapy alone is the most common treatment, for which several dose-fractionation regimens are available including single-fraction, short-course and longer-course regimens. Since these regimens are similarly effective regarding functional outcomes, patients with poor survival are optimally treated with short-course or even single-fraction radiotherapy. Longer-course radiotherapy results in better local control of malignant epidural spinal cord compression. Since most in-field recurrences occur 6 months or later, local control is particularly important for longer-term survivors who, therefore, should receive longer-course radiotherapy. It is important to estimate survival prior to treatment, which is facilitated by scoring tools. Radiotherapy should be supplemented by corticosteroids, if safely possible. Bisphosphonates and RANK-ligand inhibitors may improve local control. Selected patients can benefit from upfront decompressive surgery. Identification of these patients is facilitated by prognostic instruments considering degree of compression, myelopathy, radio-sensitivity, spinal stability, post-treatment ambulatory status, and patients' performance status and survival prognoses. Many factors including patients' preferences must be considered when designing personalized treatment regimens.

Small Molecule EGFR Inhibitors as Anti-Cancer Agents: Discovery, Mechanisms of Action, and Opportunities

Epidermal growth factor receptors (EGFRs) are a class of receptor tyrosine kinase that are also called ErbB1 and HER1. EGFR tyrosine kinase activity inhibition is considered a promising therapeutic strategy for the treatment of cancer. Many small-molecule inhibitors of EGFR tyrosine kinase (EGFR-TK), from medicinally privileged molecules to commercial drugs, have been overviewed. Particular attention has been paid to the structure of the molecule and its mechanism of action if reported. Subsequent classification of the molecules under discussion has been carried out. Both natural and synthetic and reversible and irreversible EGFR-tyrosine kinase inhibitors have been discussed. Various types of cancers that are caused by overexpression of the EGFR gene, their possible molecular origins, and their natures have also been counted in this article. Because the EGFR signaling pathway controls the proliferation, growth, survival, and differentiation of cells, and the mutated EGFR gene overproduces EGFR protein, which ultimately causes several types of cancer, proper understanding of the molecular dynamics between the protein structure and its inhibitors will lead to more effective and selective EGFR-TKIs, which in turn will be able to save more lives in the battle against cancer.

A phase Ia dose-escalation trial of Ametumumab (a fully human monoclonal antibody against epidermal growth factor receptor) in patients with advanced solid malignancies

Background:

Epidermal growth factor receptor (EGFR) is a well-known target for cancer treatment. However, the authorized anti-EGFR monoclonal antibodies generally cause several toxic effects, especially severe cutaneous toxicities as well as infusion reactions, and the clinical indications are limited. Here we developed Ametumumab, a fully human recombinant anti-EGFR monoclonal antibody.

Objectives:

To assess the safety, tolerability, pharmacokinetics (PK), and immunogenicity of Ametumumab.

Design:

A first-in-human phase Ia dose escalation study of Ametumumab in patients with advanced solid malignancies.

Methods:

An open-label, first-in-human dose escalation study was done in 22 patients with advanced malignancies who received six ascending dosages ranging from 75 to 750 mg/m2. Following a single dosage and a 28-day dose-limiting toxicity (DLT) monitoring period, patients were given repeated doses weekly. Blood samples were taken to determine the PK parameters of Ametumumab and anti-drug antibody concentrations. Every 8 weeks, radiographic tumor evaluations were conducted.

Results:

In this trial, no DLT was observed, and the maximum tolerated dose was not reached at doses up to 750 mg/m2. There were no severe adverse events but mild and moderate adverse effects, such as headache, proteinuria, and rash. Single-dose PK results demonstrated a straightforward linear relationship with dosage escalation. The medication concentrations accumulated and attained steady-state after four rounds of injections. It was calculated that 10 patients with disease control would be observed in the 22 evaluable patients. The disease control rate was 45.5%.

Conclusion:

The Ametumumab was well tolerated and safe in patients with advanced solid malignancies, exhibiting minimal immunogenicity, a long half-life, high levels of drug exposure in the blood, and preliminary effectiveness.

Registration:

The trial was registered with CTR20170343 on 10 April 2017, The China Center for Drug Evaluation.

New quinazolinone-based derivatives as DHFR/EGFR-TK inhibitors: Synthesis, molecular modeling simulations, and anticancer activity

New 2-mercapto-quinazolin-4-one analogs were synthesized and tested for their in vitro anticancer activity, dihydrofolate reductase (DHFR) inhibition, and epidermal growth factor tyrosine kinase (EGFR-TK) inhibition activities. Compound 24, which is characterized by a 2-benzyl-thio function, showed broad-spectrum anticancer activity with high safety profile and selectivity index. The concentrations of 24 causing 50% growth inhibition (GI₅₀ ) and total cell growth inhibition (TGI) and its lethal concentration 50 (LC₅₀ ) were 15.1, 52.5, and 91.2 µM, respectively, using 5-fluorouracil as a positive control. Also, it showed EGFR-TK inhibitory activity with IC₅₀  = 13.40 nM compared to gefitinib (IC₅₀  = 18.14 nM) and DHFR inhibitory potency with 0.30 μM compared to methotrexate (MTX; IC₅₀  = 0.08 μM). In addition, compound 24 caused cell cycle arrest and apoptosis on COLO-205 colon cancer cells. Compounds 37, 21, and 54 showed remarkable DHFR inhibitory activity with IC₅₀ values of 0.03, 0.08, and 0.08 μM, respectively. The inhibitory properties of these compounds are due to an electron-withdrawing group on the quinazolinone ring, except for compound 54. In a molecular modeling study, compound 24 showed the same binding mode as gefitinib as it interacted with the amino acid Lys745 via π-π interaction. Compound 37 showed a similar binding mode as MTX through the binding interaction with Lys68, Asn64 via hydrogen bond acceptor, and Phe31 via arene-arene interaction. The obtained model and substitution pattern could be used for further development.

Trends in anti-HER2 drugs consumption and influencing factors

Background

Human epidermal growth factor receptor 2 (HER2) inhibitors have been approved to treat various cancers with HER2 amplification. The Chinese government has made great efforts to improve the availability and affordability of these drugs. This study aimed to analyze the trends in anti-HER2 drug consumptions in Nanjing from 2012 to 2021, and explore influencing factors.

Methods

Data about use of anti-HER2 drugs in 2012-2021 were extracted from Jiangsu Medicine Information Institute. Six types of anti-HER2 drugs were included. Drug consumption was expressed as defined daily doses (DDDs) and expenditure. Time series analysis was adopted to find trends in consumption, while interrupted time series was used in analyzing the impact of policy on consumption. The correlation between DDDs and defined daily cost (DDC) was analyzed by Pearson's correlation test.

Results

The DDC, DDDs, and expenditure of anti-HER2 drugs changed little from 2012 to 2016. The DDC decreased intermittently, while the DDDs and expenditure of these drugs grew continuously from 2017 to 2021. The anti-HER2 monoclonal antibodies contributed to the majority of total consumption in 2012-2019. The DDDs of anti-HER2 tyrosine kinase inhibitors surpassed the DDDs of monoclonal antibodies in 2020-2021. Trastuzumab was the predominantly prescribed drug in 2012-2019, but the DDDs of pyrotinib surpassed the DDDs of trastuzumab in 2020-2021. The ln value of DDC or self-paid DDC of trastuzumab was negatively correlated with the ln value of its DDDs. The national health insurance coverage (NHIC) and national drug price negotiation policy about anti-HER2 drugs were initiated in 2017. Low-price generics and biosimilar of trastuzumab came into the market in 2020 and 2021, separately. Interrupted time series analysis showed that the DDDs increased significantly after the implementation of NHIC, price negotiation or generic drug replacement.

Conclusion

The consumption of anti-HER2 drugs has significantly increased and their DDC has decreased after the implementation of NHIC, price negotiation, or low-price generic drug replacement since 2017. Further efforts are needed to translate the high consumption into clinical benefits.

Hypercompact adenine base editors based on transposase B guided by engineered RNA

Transposon-associated transposase B (TnpB) is deemed an ancestral protein for type V, Cas12 family members, and the closest ancestor to UnCas12f1. Previously, we reported a set of engineered guide RNAs supporting high indel efficiency for Cas12f1 in human cells. Here we suggest a new technology whereby the engineered guide RNAs also manifest high-efficiency programmable endonuclease activity for TnpB. We have termed this technology TaRGET (TnpB-augment RNA-based Genome Editing Technology). Having this feature in mind, we established TnpB-based adenine base editors (ABEs). A Tad-Tad mutant (V106W, D108Q) dimer fused to the C terminus of dTnpB (D354A) showed the highest levels of A-to-G conversion. The limited targetable sites for TaRGET-ABE were expanded with engineered variants of TnpB or optimized deaminases. Delivery of TaRGET-ABE also ensured potent A-to-G conversion rates in mammalian genomes. Collectively, the TaRGET-ABE will contribute to improving precise genome-editing tools that can be delivered by adeno-associated viruses, thereby harnessing the development of clustered regularly interspaced short palindromic repeats (CRISPR)-based gene therapy.

The multi-kinase inhibitor afatinib serves as a novel candidate for the treatment of human uveal melanoma

PURPOSE

Uveal melanoma (UM) is the most common intraocular malignancy in adults with a poor prognosis and a high recurrence rate. Currently there is no effective treatment for UM. Multi-kinase inhibitors targeting dysregulated pro-tumorigenic signalling pathways have revolutionised anti-cancer treatment but, as yet, their efficacy in UM has not been established. Here, we identified the multi-kinase inhibitor afatinib as a highly effective agent that exerts anti-UM effects in in vitro, ex vivo and in vivo models.

METHODS

We assessed the anti-cancer effects of afatinib using cell viability, cell death and cell cycle assays in in vitro and ex vivo UM models. The signaling pathways involved in the anti-UM effects of afatinib were evaluated by Western blotting. The in vivo activity of afatinib was evaluated in UM xenograft models using tumour mass measurement, PET scan, immunohistochemical staining and TUNEL assays.

RESULTS

We found that afatinib reduced cell viability and activated apoptosis and cell cycle arrest in multiple established UM cell lines and in patient tumour-derived primary cell lines. Afatinib impaired cell migration and enhanced reproductive death in these UM cell models. Afatinib-induced cell death was accompanied by activation of STAT1 expression and downregulation of Bcl-xL and cyclin D1 expression, which control cell survival and cell cycle progression. Afatinib attenuated HER2-AKT/ERK/PI3K signalling in UM cell lines. Consistent with these observations, we found that afatinib suppressed tumour growth in UM xenografted mice.

CONCLUSION

Our data indicate that afatinib activates UM cell death and targets the HER2-mediated cascade, which modulates STAT1-Bcl-xL/cyclin D1 signalling. Thus, targeting HER2 with agents like afatinib may be a novel therapeutic strategy to treat UM and to prevent metastasis.

A New and Easy-to-Use Survival Score for Patients Irradiated for Metastatic Epidural Spinal Cord Compression

PURPOSE

A survival score was created in 2008 to improve treatment personalization of patients irradiated for metastatic epidural spinal cord compression (MESCC). Since then, targeted therapies improved survival of patients with cancer, which may decrease this score's predictive value. A new score appears necessary.

METHODS AND MATERIALS

Two hundred sixty-four patients receiving radiation therapy without surgery in prospective trials (2010-2021) were included. A dose-fractionation regimen plus 15 factors were analyzed: age, sex, tumor type, interval tumor diagnosis to MESCC, MESCC sites, affected vertebrae, additional bone lesions, other distant lesions (yes or no), number of organs involved by metastases, time developing motor deficits, ambulatory status, sensory function, sphincter dysfunction, pain, and distress. Six-month survival rates (%) of independent prognostic factors were divided by 10 and summed for each patient. The score was compared with the previous tool for predicting death ≤6 months and survival ≥6 months.

RESULTS

In a multivariate analysis, tumor type (P = .001), other distant lesions (P < .001), and ambulatory status (P < .001) were significant. Based on 6-month survival rates, 4 groups (8-9, 10-13, 14-17, and 18 points) were created with 6-month survival rates of 12.8%, 34.7%, 62.8%, and 90.0%, respectively (version A). For version B, "other distant lesions" was replaced by "number of organs involved by metastases." Version B included 4 groups (8-10, 11-14, 15-16, and 17 points) with 6-month survival rates of 11.1%, 42.0%, 68.6%, and 91.7%, respectively. Positive predictive values to predict death ≤6 months were 87.2% (version A) and 88.9% (version B) versus 76.6% (3 groups) and 84.6% (5 groups) for the previous score. Positive predictive values to predict survival ≥6 months were 90.0% and 91.7% versus 59.0% and 64.3%.

CONCLUSIONS

Both versions of the new score were more precise than the previous tool. Version B appears slightly superior to version A but requires more extensive diagnostic staging that may not be readily available when emergently treating.

Fear Stress During Pregnancy Affects Placental m6A-Modifying Enzyme Expression and Epigenetic Modification Levels

As the hub connecting mother and offspring, the placenta’s normal development is vital for fetal growth. Fear stress can cause some structural alterations in the placenta and affect placental development and function. N6-methyladenosine (m6A) is the most common mRNA modification and is involved in regulating the development of the placenta and embryo. There are no reports on the potential role of m6A modification in placental damage caused by fear stress during pregnancy. In this study, we demonstrated that fear stress during pregnancy increases the levels of methylated enzymes (METTL3, METTL14, and WTAP), decreases the levels of demethylase FTO, and increases the overall methylation levels in the placenta of pregnant rats. MeRIP-seq data analysis revealed 22,010 m6A peaks associated with 12,219 genes in the placenta of the model and 21,060 m6A peaks associated with 11,730 genes in the placenta of the control. The peaks were mainly concentrated in the coding region and the 3ʹ untranslated region. In addition, 50 genes with abnormal modification and expression (double aberrant genes) were screened out by combining MeRIP-seq and RNA-seq data. Mefv, Erbb2, and Cgas were selected from 50 double aberrant genes, and MeRIP-qPCR and real-time quantitative polymerase chain reaction were used to verify their modification and expression levels. Our findings suggest that m6A modifications play an important role in placental dysfunction induced by fear stress during pregnancy.

Melatonin Modulation of Radiation-Induced Molecular Changes in MCF-7 Human Breast Cancer Cells

Radiation therapy is an important component of cancer treatment scheduled for cancer patients, although it can cause numerous deleterious effects. The use of adjuvant molecules aims to limit the damage in normal surrounding tissues and enhance the effects of radiation therapy, either killing tumor cells or slowing down their growth. Melatonin, an indoleamine released by the pineal gland, behaves as a radiosensitizer in breast cancer, since it enhances the therapeutic effects of ionizing radiation and mitigates side effects on normal cells. However, the molecular mechanisms through which melatonin modulates the molecular changes triggered by radiotherapy remain mostly unknown. Here, we report that melatonin potentiated the anti-proliferative effect of radiation in MCF-7 cells. Treatment with ionizing radiation induced changes in the expression of many genes. Out of a total of 25 genes altered by radiation, melatonin potentiated changes in 13 of them, whereas the effect was reverted in another 10 cases. Among them, melatonin elevated the levels of PTEN and NME1, and decreased the levels of SNAI2, ERBB2, AKT, SERPINE1, SFN, PLAU, ATM and N3RC1. We also analyzed the expression of several microRNAs and found that melatonin enhanced the effect of radiation on the levels of miR-20a, miR-19a, miR-93, miR-20b and miR-29a. Rather surprisingly, radiation induced miR-17, miR-141 and miR-15a but melatonin treatment prior to radiation counteracted this stimulatory effect. Radiation alone enhanced the expression of the cancer suppressor miR-34a, and melatonin strongly stimulated this effect. Melatonin further enhanced the radiation-mediated inhibition of Akt. Finally, in an in vivo assay, melatonin restrained new vascularization in combination with ionizing radiation. Our results confirm that melatonin blocks many of the undesirable effects of ionizing radiation in MCF-7 cells and enhances changes that lead to optimized treatment results. This article highlights the effectiveness of melatonin as both a radiosensitizer and a radioprotector in breast cancer. Melatonin is an effective adjuvant molecule to radiotherapy, promoting anti-cancer therapeutic effects in cancer treatment. Melatonin modulates molecular pathways altered by radiation, and its use in clinic might lead to improved therapeutic outcomes by enhancing the sensitivity of cancerous cells to radiation and, in general, reversing their resistance toward currently applied therapeutic modalities.

The Landscape of Aminoacyl-tRNA Synthetases Involved in Severe Acute Respiratory Syndrome Coronavirus 2 Infection

Aminoacyl-tRNA synthetases (aaRSs) are essential enzymes in translation by linking amino acids onto their cognate tRNAs during protein synthesis. During evolution, aaRSs develop numerous non-canonical functions that expand the roles of aaRSs in eukaryotic organisms. Although aaRSs have been implicated in viral infection, the function of aaRSs during infections with coronaviruses (CoVs) remains unclear. Here, we analyzed the data from transcriptomic and proteomic database on human cytoplasmic (cyto) and mitochondrial (mt) aaRSs across infections with three highly pathogenic human CoVs, with a particular focus on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We found an overall downregulation of aaRSs at mRNA levels, while the protein levels of some mt-aaRSs and the phosphorylation of certain aaRSs were increased in response to SARS-CoV-2 infection. Strikingly, interaction network between SARS-CoV-2 and human aaRSs displayed a strong involvement of mt-aaRSs. Further co-immunoprecipitation (co-IP) experiments confirmed the physical interaction between SARS-CoV-2 M protein and TARS2. In addition, we identified the intermediate nodes and potential pathways involved in SARS-CoV-2 infection. This study provides an unbiased, overarching perspective on the correlation between aaRSs and SARS-CoV-2. More importantly, this work identifies TARS2, HARS2, and EARS2 as potential key factors involved in COVID-19.

Alcohol and Head and Neck Cancer: Updates on the Role of Oxidative Stress, Genetic, Epigenetics, Oral Microbiota, Antioxidants, and Alkylating Agents

Head and neck cancer (HNC) concerns more than 890,000 patients worldwide annually and is associated with the advanced stage at presentation and heavy outcomes. Alcohol drinking, together with tobacco smoking, and human papillomavirus infection are the main recognized risk factors. The tumorigenesis of HNC represents an intricate sequential process that implicates a gradual acquisition of genetic and epigenetics alterations targeting crucial pathways regulating cell growth, motility, and stromal interactions. Tumor microenvironment and growth factors also play a major role in HNC. Alcohol toxicity is caused both directly by ethanol and indirectly by its metabolic products, with the involvement of the oral microbiota and oxidative stress; alcohol might enhance the exposure of epithelial cells to carcinogens, causing epigenetic modifications, DNA damage, and inaccurate DNA repair with the formation of DNA adducts. Long-term markers of alcohol consumption, especially those detected in the hair, may provide crucial information on the real alcohol drinking of HNC patients. Strategies for prevention could include food supplements as polyphenols, and alkylating drugs as therapy that play a key role in HNC management. Indeed, polyphenols throughout their antioxidant and anti-inflammatory actions may counteract or limit the toxic effect of alcohol whereas alkylating agents inhibiting cancer cells' growth could reduce the carcinogenic damage induced by alcohol. Despite the established association between alcohol and HNC, a concerning pattern of alcohol consumption in survivors of HNC has been shown. It is of primary importance to increase the awareness of cancer risks associated with alcohol consumption, both in oncologic patients and the general population, to provide advice for reducing HNC prevalence and complications.