Background/Objectives: Triple-negative breast cancer (TNBC) is a highly aggressive subtype with limited therapeutic options, and identifying reliable biomarkers for diagnosis and prognosis is crucial for improving patient outcomes. Mitochondrial DNA (mtDNA) copy number has been linked to an increased risk of developing various types of cancer, including breast cancer. However, there is a lack of understanding regarding how mtDNA copy number variations may influence the development and progression of TNBC. Methods: This study investigated mtDNA copy number in TNBC tumors and corresponding normal breast tissues from 23 TNBC patients who received neoadjuvant chemotherapy. The relative mtDNA copy number was estimated using quantitative PCR for the NADH dehydrogenase subunit 1 (ND1) and subunit 5 (ND5) regions. Results: The results showed a significant decrease in mtDNA copy number in TNBC tumor tissues compared to corresponding normal breast tissue. However, no significant correlation was found between mtDNA content and clinical parameters such as age, tumor size, or chemotherapy response. Conclusions: These results suggest that while mtDNA content decreases in TNBC tumors, it may not directly influence these clinical characteristics. Despite some inconsistencies in the literature regarding mtDNA dynamics in cancer, this study supports the potential of mtDNA as a biomarker for TNBC. Larger cohort studies are needed to further validate these results and explore the role of mtDNA in guiding personalized treatment strategies for TNBC patients.

The special bilayer structure of mitochondrion is a promising therapeutic target in the diagnosis and treatment of diseases such as cancer and metabolic diseases. Nanocarriers such as liposomes modified with mitochondriotropic moieties can be developed to send therapeutic molecules to mitochondria. In this study, DSPE-PEG-TPP polymer conjugate was synthesized and used to prepare mitochondria-targeted liposomes (TPPLs) to improve the therapeutic index of chemotherapeutic agents functioning in mitochondria and reduce their side effects. Doxorubicin (Dox) loaded-TPPL and non-targeted PEGylated liposomes (PPLs) were prepared and compared based on physicochemical properties, morphology, release profile, cellular uptake, mitochondrial localization, and anticancer effects. All formulations were spherically shaped with appropriate size, dispersity, and zeta potential. The stability of the liposomes was favorable for two months at 4 °C. TPPLs localize to mitochondria, whereas PPLs do not. The empty TPPLs and PPLs were not cytotoxic to HCT116 cells. The release kinetics of Dox-loaded liposomes showed that Dox released from TPPLs was higher at pH 5.6 than at pH 7.4, which indicates a higher accumulation of the released drug in the tumor environment. The half-maximal inhibitory concentration of Dox-loaded TPPLs and PPLs was 1.62-fold and 1.17-fold lower than that of free Dox due to sustained drug release, respectively. The reactive oxygen species level was significantly increased when HCT116 cells were treated with Dox-loaded TPPLs. In conclusion, TPPLs may be promising carriers for targeted drug delivery to tumor mitochondria.

Background: The properties of nanoparticle surfaces are crucial in influencing their interaction with biological environments, as well as their stability, biocompatibility, targeting abilities, and cellular uptake. Hydrophobin 4 (HFB4) is a class II HFB protein produced by filamentous fungi that has a natural ability to self-assemble at hydrophobic-hydrophilic interfaces. The biocompatible, non-toxic, biodegradable, and amphipathic properties of HFB4 render it valuable for improving the solubility and bioavailability of hydrophobic drugs. We have investigated the physicochemical properties, cellular uptake, and anticancer effects of empty and Doxorubicin (Dox)-loaded HFB4 liposomes (HFB4L) and compared them to those of PEGylated liposomes (PPL). Methods: The Pichia pastoris KM71H strain was used for HFB4 purification. Liposomes were prepared through the thin film hydration method and characterized. The cytotoxic effects of free Dox, Dox-HFB4, and Dox-PPL were assessed in MCF7 cells using the SRB Assay. Results: All formulations showed good size homogeneity and a spherical shape. The HFB4 coating enhanced the physicochemical stability of Dox-HFB4L over 60 days at 4 °C without significantly affecting Dox release from HFB4L. It increased Dox release at pH 5.4 compared to pH 7.4, indicating higher delivery of drugs into acidic tumor environments, similar to Dox-PPL. While both formulations showed increased cellular uptake compared to free Dox, they exhibited a lower anticancer effect due to the sustained release of Dox. Notably, Dox-HFB4L displayed greater cytotoxicity than Dox-PPL in MCF7 cells. Conclusions: HFB4L may offer superior benefits in terms of delivering drugs to an acidic tumor environment in a stable, non-toxic, and sustained manner.

Pathogenic variations in the BRCA2 gene have been detected with the development of next-generation sequencing (NGS)-based hereditary cancer panel testing technology. It also reveals an increasing number of variants of uncertain significance (VUSs). Well-established functional tests are crucial to accurately reclassifying VUSs for effective diagnosis and treatment. We retrospectively analyzed the multi-gene cancer panel results of 922 individuals and performed in silico analysis following ClinVar classification. Then, we selected five breast cancer-diagnosed patients’ missense BRCA2 VUSs (T1011R, T1104P/M1168K, R2027K, G2044A, and D2819) for reclassification. The effects of VUSs on BRCA2 function were analyzed using comet and H2AX phosphorylation (γH2AX) assays before and after the treatment of peripheral blood mononuclear cells (PBMCs) of subjects with the double-strand break (DSB) agent doxorubicin (Dox). Before and after Dox-induction, the amount of DNA in the comet tails was similar in VUS carriers; however, notable variations in γH2AX were observed, and according to combined computational and functional analyses, we reclassified T1001R as VUS-intermediate, T1104P/M1168K and D2819V as VUS (+), and R2027K and G2044A as likely benign. These findings highlight the importance of the variability of VUSs in response to DNA damage before and after Dox-induction and suggest that further investigation is needed to understand the underlying mechanisms.

Psoriasis, a common immune-mediated chronic inflammatory disease, may arise from genetic, epigenetic, and immune system factors. Current medications focus on symptom relief, presenting a challenge in discovering new compounds or methods for safe and effective psoriasis management while ensuring patient adherence. Statin drugs like fluvastatin, initially for dyslipidemia, were considered beneficial for treating psoriasis. Thus the objective of this study was to formulate novel topical transethosomes as drug delivery systems for dermal administration of fluvastatin sodium (fluvastatin) in psoriasis treatment. The thin film hydration method was exploited to prepare fluvastatin loaded transethosomes consisted of Phospholipon 90 as the phospholipid, along with Tween 20 or Tween 80 as the edge activators. The physicochemical properties of the transethosomes, including particle size and size distribution, zeta potential, encapsulation efficiency, pH, and conductivity, were evaluated. Attenuated Total Reflectance Fourier Transformed Infrared (ATR-FTIR) analysis was conducted to determine the structural characteristics, while Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) analyses were employed to examine the morphological properties. Additionally, the stability of the transethosomes was monitored. Transfersome-type delivery systems were also developed for comparison with the transethosome formulations. The in vitro skin penetration and deposition behavior of fluvastatin transethosomes were assessed using sequential tape stripping, ATR-FTIR Spectroscopy, and Confocal Laser Scanning Microscopy (CLSM) and compared to fluvastatin-loaded transfersomes. Furthermore, in vitro cell culture studies were conducted to evaluate the cytotoxicity and antipsoriatic activities of the fluvastatin-loaded transethosomal carrier systems that exhibited the highest dermal accumulation. The results suggest that fluvastatin-loaded transethosomes inhibit the IL6 and IL8 production in HaCaT cells compared to free fluvastatin. Overall, the aim of this research is to develop innovative, skin-compatible, and stable drug delivery systems that improve the effectiveness of psoriasis treatment. This would be achieved by targeting the active substance, fluvastatin, which is believed to have potential antipsoriatic effects, specifically to the affected area of the skin.

Synthetic lethality in DNA repair pathways is an important strategy for the selective treatment of cancer cells without harming healthy cells and developing cancer-specific drugs. The synthetic lethal interaction between the mismatch repair (MMR) protein, MutL homolog 1 (MLH1), and the mitochondrial base excision repair protein, DNA polymerase γ (Pol γ) was used in this study for the selective treatment of MLH1 deficient cancers. Germline mutations in the MLH1 gene and aberrant MLH1 promoter methylation result in an increased risk of developing many cancers, including nonpolyposis colorectal and endometrial cancers. Because the inhibition of Pol γ in MLH1 deficient cancer cells provides the synthetic lethal selectivity, we conducted a comprehensive small molecule screening from various databases and chemical drug library molecules for novel Pol γ inhibitors that selectively kill MLH1 deficient cancer cells. We characterized these Pol γ inhibitor molecules in vitro and in vivo, and identified 3,3’-[(1,1’-Biphenyl)-4’,4’-diyl)bis(azo)]bis[4-amino-1-naphthalenesulfonic acid] (congo red; CR; Zinc 03830554) as a high-affinity binder to the Pol γ protein and potent inhibitor of the Pol γ strand displacement and one-nucleotide incorporation DNA synthesis activities in vitro and in vivo. CR reduced the cell proliferation of MLH1 deficient HCT116 human colon cancer cells and suppressed HCT116 xenograft tumor growth whereas it did not affect the MLH1 proficient cell proliferation and xenograft tumor growth. CR caused mitochondrial dysfunction and cell death by inhibiting Pol γ activity and oxidative mtDNA damage repair, increasing the production of reactive oxygen species and oxidative mtDNA damage in MLH1 deficient cells. This study suggests that the Pol γ inhibitor, CR may be further evaluated for the MLH1 deficient cancers’ therapy.

Vitamin D deficiency is common among postmenopausal women. Telomere length can be a potential protective mechanism for age-related diseases. The objective of our study is to examine the association of vitamin D supplementation on leukocyte telomere length (LTL) in healthy postmenopausal women with vitamin D deficiency. The study was designed as a placebo-controlled study to investigate the short-term effects of vitamin D supplementation and seasonal changes on vitamin D related parameters, including 25(OH)D, 1,25(OH)2D parathormone (PTH), Vitamin D binding protein (VDBP), vitamin D receptor (VDR), and telomere length in a cohort of postmenopausal women (n = 102). The group was divided as supplementation (n = 52) and placebo groups (n = 50). All parameters were measured before and after treatment. Serum VDBP levels were measured by ELISA method and VDR, GC (VDBP) gene expressions and relative telomere lengths were measured in peripheral blood mononuclear cells (PBMC) using a quantitative real-time PCR method. The results demonstrate that baseline levels were similar between the groups. After vitamin D supplementation 25(OH)D, 1,25(OH)2D, PTH and VDBP levels were changed significantly compared to the placebo group. At the end of the study period, LTL levels were significantly increased in both groups and this change was more prominent in placebo group. The change in GC expression was significant between treatment and placebo groups but VDR expression remained unchanged. Even though the study was designed to solely assess the effects of vitamin D supplementation, LTL was significantly increased in the whole study group in summer months suggesting that LTL levels are affected by sun exposure and seasonal changes rather than supplementation. The study displayed the short-term effect of Vitamin D supplementation on vitamin D, PTH levels, LTL and vitamin D associated gene expressions. The relation between Vitamin D and LTL is not linear and could be confounded by several factors such as the population differences, regional and seasonal changes in sun exposure.

Objective:Most patients with non-muscle-invasive bladder cancer (NMIBC) do not respond to intravesical Bacillus Calmette-Guerin (BCG) immunotherapy and have high risk of NMIBC recurrence and progression. In addition to its therapeutic effect which increases the local immune response, BCG also exerts an anti-tumour effect by increasing oxidative stress, and producing reactive oxygen species and oxidative DNA damage in bladder cancer (BC) cells. The oxidative DNA damage is repaired by base excision repair (BER) mechanism. Thus, BER capacity of BC cells could be an important factor in response to BCG therapy. Effects of BCG on the activity of BER in BC transitional carcinoma cell line, T24 have been investigated.Materials and Methods:The uracil-initiated total BER and BER enzyme activities were measured in whole cell extracts with or without BCG treatment using a [γ-32P] adenosine triphosphate-labelled 51-mer DNA substrates.Results:BCG treatment increased the activities of uracil-initiated total BER and BER enzymes, uracil DNA glycosylase and DNA polymerase β in 6 h and 24 h repair periods and increased the activity of 8-oxoguanine DNA glycosylase in 6 h repair in T24 BC cell line.Conclusion:The enhanced BER activity in BC cells in response to BCG treatment could be an important factor in BCG resistance.

Objective: High levels of endonuclease III-like 1 (NTHL1) DNA glycosylase, which plays a role in the first step of the base excision repair pathway, has been related to cancer initiation and progression.5-hydroxyuracil (5-OHU) oxidative base damage is a substrate for NTHL1 and endonuclease VIII-like 1 enzyme 1 (NEIL1) DNA glycosylases.This study investigates the association of 5-OHU incision activity with the risk of disease progression in patients with non-muscle-invasive bladder cancer (NMIBC) regarding grade and stage.Materials and Methods: During transurethral resection of 17 NMIBC patients, the papillary tumour before monopolar resection and healthy bladder mucosal tissue from the same person were obtained using cold cup biopsy.Both the normal mucosa and NMIBC tumour were pathologically confirmed.The histological grade and stage were also determined.The 5-OHU incision activity of all tissues was measured using a radiolabelled 5-OHU modified base containing DNA substrate.Results: 5-OHU incision activity was significantly higher in all high-grade NMIBC tissue extracts compared with the corresponding normal tissues (p=0.001).However, we found no significant difference in 5-OHU incision activity in low-grade NMIBC tissues (p=0.89).There was also a significant increase in 5-OHU incision activity at the Ta/T1 stage compared with the corresponding normal tissue (p=0.001). Conclusion:The increase in 5-OHU incision activity according to the histological grade of NMIBC tissue indicates that this activity (mainly performed by NTHL1 and NEIL1 DNA glycosylases) might play a role in NMIBC prognosis.Thus, it could be used as a potential prognostic biomarker for NMIBC.

Heterozygous relatives of ataxia‐telangiectasia (AT) patients are at an increased risk for certain AT‐related manifestations. We also show that there is an increase of infection frequency in parents of AT patients. Thus, we hypothesized that the parents might exhibit immune alterations similar to their affected children.

Background and Aims: Since 1980's, several preclinical studies have been published on the anti-colorectal cancer activity of the nonsteroidal anti-inflammatory drug indomethacin. The direct anti-proliferative effect of indomethacin seems to occur via a variety of reported COX-independent mechanisms. Acemetacin is a glycolic acid ester derivative of indomethacin and contrary to indomethacin, there is not much published research on anti-cancer effects of acemetacin. Herein, we compared the in vitro anti-proliferative properties of indomethacin, acemetacin, and their tromethamine salts in HCT116 colon cancer cells. Methods: The tromethamine salts of indomethacin and acemetacin were synthesized and the structures were established by microanalysis, IR, 1 H-NMR, 13C-NMR (APT) and 2D-NMR (HSQC and HMBC) spectrometry. Cell proliferation assays were performed using xCELLigence real-time cell analysis system. Results: Indomethacin exhibited profound inhibitory effects with IC50 values at low micromolar ranges. Acemetacin exhibited far lower cytotoxic activity as compared to that of indomethacin. Surprisingly, indomethacin-tromethamine salt was 2-fold and 4.4-fold more potent than indomethacin at 48 and 72 h, respectively, while maintaining its activity at 24 h. The tromethamine salt of acemetacin was more potent than acemetacin at 24 h and 48 h post-treatment. Conclusion: The anti-proliferative effect of indomethacin in HCT116 cells was found to be at low micro-molar levels. The esterification of indomethacin with glycolic acid caused a strong decrease in anti-proliferative effect. The salt formation caused a positive effect on the anti-proliferative activity of indomethacin and indomethacin-tromethamine salt may be a promising candidate for additional in vivo studies.

The molecular mechanisms underlying the development and progression of bladder cancer (BC) are complex and have not been fully elucidated. Alterations in base excision repair (BER) capacity, one of several DNA repair mechanisms assigned to preserving genome integrity, have been reported to influence cancer susceptibility, recurrence, and progression, as well as responses to chemotherapy and radiotherapy. We report herein that non-muscle invasive BC (NMIBC) tissues exhibit increased uracil incision, abasic endonuclease and gap-filling activities, as well as total BER capacity in comparison to normal bladder tissue from the same patient (p < 0.05). No significant difference was detected in 8-oxoG incision activity between cancer and normal tissues. NMIBC tissues have elevated protein levels of uracil DNA glycosylase, 8-oxoguanine DNA glycosylase, AP endonuclease 1 and DNA polymerase β protein. Moreover, the fold increase in total BER and the individual BER enzyme activities were greater in high-grade tissues than in low-grade NMIBC tissues. These findings suggest that enhanced BER activity may play a role in the etiology of NMIBC and that BER proteins could serve as biomarkers in disease prognosis, progression or response to genotoxic therapeutics, such as Bacillus Calmette–Guérin.

Base excision repair (BER) defects and concomitant oxidative DNA damage accumulation play a role in the etiology and progression of late-onset Alzheimer's disease (LOAD). However, it is not known whether genetic variant(s) of specific BER genes contribute to reduced BER activity in LOAD patients and whether they are associated with risk, development and/or progression of LOAD. Therefore, we performed targeted next generation sequencing for three BER genes, uracil glycosylase (UNG), endonuclease VIII-like DNA glycosylase 1 (NEIL1) and polymerase β (POLβ) including promoter, exonic and intronic regions in peripheral blood samples and postmortem brain tissues (temporal cortex, TC and cerebellum, CE) from LOAD patients, high-pathology control and cognitively normal age-matched controls. In addition, the known LOAD risk factor, APOE was included in this study to test whether any BER gene variants associate with APOE variants, particularly APOE ε4. We show that UNG carry five significant variants (rs1610925, rs2268406, rs80001089, rs1018782 and rs1018783) in blood samples of Turkish LOAD patients compared to age-matched controls and one of them (UNG rs80001089) is also significant in TC from Brazilian LOAD patients (p<0.05). The significant variants present only in CE and TC from LOAD are UNG rs2569987 and POLβ rs1012381950, respectively. There is also significant epistatic relationship (p = 0.0410) between UNG rs80001089 and NEIL1 rs7182283 in TC from LOAD subjects. Our results suggest that significant BER gene variants may be associated with the risk of LOAD in non-APOE ε4 carriers. On the other hand, there are no significant UNG, NEIL1 and POLβ variants that could affect their protein level and function, suggesting that there may be other factors such as post-transcriptional or-translational modifications responsible for the reduced activities and protein levels of these genes in LOAD pathogenesis. Further studies with increased sample size are needed to confirm the relationship between BER variants and LOAD risk.

Background: Pathological inflammatory syndromes of unknown etiology are commonly observed in ataxia telangiectasia (AT) and Artemis deficiency. Similar inflammatory manifestations also exist in patients with STING-associated vasculopathy in infancy (SAVI). Objective: We sought to test the hypothesis that the inflammation-associated manifestations observed in patients with AT and Artemis deficiency stem from increased type I IFN signature leading to neutrophil-mediated pathological damage. Methods: Cytokine/protein signatures were determined by ELISA, cytometric bead array, or quantitative PCR. Stat1 phosphorylation levels were determined by flow cytometry. DNA species accumulating in the cytosol of patients' cells were quantified microscopically and flow cytometrically. Propensity of isolated polymorhonuclear granulocytes to form neutrophil extracellular traps (NETs) was determined using fluorescence microscopy and picogreen assay. Neutrophil reactive oxygen species levels and mitochondrial stress were assayed using fluorogenic probes, microscopy, and flow cytometry. Results: Type I and III IFNsignatures were elevated in plasma and peripheral blood cells of patients with AT, Artemis deficiency, and SAVI. Chronic IFN production stemmed fromthe accumulation of DNA in the cytoplasm of ATand Artemis-deficient cells. Neutrophils isolated from patients spontaneously produced NETs and displayed indicators of oxidative and mitochondrial stress, supportive of theirNETotic tendencies. Asimilar phenomenonwas also observed in neutrophils from healthy controls exposed to patient plasma samples or exogeneous IFN-alpha. Conclusions: Type I IFN-mediated neutrophil activation and NET formation may contribute to inflammatory manifestations observed in patients with AT, Artemis deficiency, and SAVI. Thus, neutrophils represent a promising target to manage inflammatory syndromes in diseases with active type I IFN signature.

Cockayne Syndrome is a segmental premature aging syndrome, which can be caused by loss of function of the CSB protein. CSB is essential for genome maintenance and has numerous interaction partners with established roles in different DNA repair pathways including transcription coupled nucleotide excision repair and base excision repair. Here, we describe a new interaction partner for CSB, the DNA glycosylase NEIL2. Using both cell extracts and recombinant proteins, CSB and NEIL2 were found to physically interact independently of DNA. We further found that CSB is able to stimulate NEIL2 glycosylase activity on a 5-hydroxyl uracil lesion in a DNA bubble structure substrate in vitro. A novel 4,6-diamino-5-formamidopyrimidine (FapyA) specific incision activity of NEIL2 was also stimulated by CSB. To further elucidate the biological role of the interaction, immunofluorescence studies were performed, showing an increase in cytoplasmic CSB and NEIL2 co-localization after oxidative stress. Additionally, stalling of the progression of the transcription bubble with α-amanitin resulted in increased co-localization of CSB and NEIL2. Finally, CSB knockdown resulted in reduced incision of 8-hydroxyguanine in a DNA bubble structure using whole cell extracts. Taken together, our data supports a biological role for CSB and NEIL2 in transcription associated base excision repair.