Platinum-DNA interactions and subsequent cellular processes controlling sensitivity to anticancer platinum complexes

Endowing Pt(IV) with Perfluorocarbon Chains and Human Serum Albumin Encapsulation for Highly Effective Antitumor Chemoimmunotherapy

Tumor metastases and reoccurrence are considered the leading causes of cancer-associated deaths. As an emerging therapeutic method, increasing research efforts have been devoted to immunogenic cell death (ICD)-inducing compounds to solve the challenge. The clinically approved chemotherapeutic Pt complexes are not or are only poorly able to trigger ICD. Herein, the axial functionalization of the Pt(II) complex cisplatin with perfluorocarbon chains into ICD-inducing Pt(IV) prodrugs is reported. Strikingly, while the Pt(II) complex as well as the perfluorocarbon ligands did not induce ICD, the Pt(IV) prodrug demonstrated unexpectantly the induction of ICD through accumulation in the endoplasmic reticulum and generation of reactive oxygen species in this organelle. To enhance the pharmacological properties, the compound was encapsulated with human serum albumin into nanoparticles. While selectively accumulating in the tumorous tissue, the nanoparticles demonstrated a strong tumor growth inhibitory effect against osteosarcoma inside a mouse model. In vivo tumor vaccine analysis also demonstrated the ability of Pt(IV) to be an ideal ICD inducer. Overall, this study reports on axially perfluorocarbon chain-modified Pt(IV) complexes for ICD induction and chemoimmunotherapy in osteosarcoma.

Molecular Pathways of Colorectal Cancer Development: Mechanisms of Action and Evolution of Main Systemic Therapy Compunds

BACKGROUND

Colorectal cancer is known as one of the "big killers" in oncology given its burden in terms on morbidity and mortality. Since the second half of the last century, similarly to what happened for other solid tumors, a large series of cytotoxic molecules have been developed and tested to treat this disease.

SUMMARY

Following new discoveries in terms of colorectal cancer pathogenesis and specific pathways involved such as angiogenesis, a new series of drugs have been developed: targeted therapies.

KEY MESSAGES

In this review, we will briefly describe colorectal cancer molecular biology and its main pathways in order to retrace the main stages of oncological treatment development for colorectal cancer from the first available treatments to novel approaches to the disease.

The cross talk of ubiquitination and chemotherapy tolerance in colorectal cancer

Ubiquitination, a highly adaptable post-translational modification, plays a pivotal role in maintaining cellular protein homeostasis, encompassing cancer chemoresistance-associated proteins. Recent findings have indicated a potential correlation between perturbations in the ubiquitination process and the emergence of drug resistance in CRC cancer. Consequently, numerous studies have spurred the advancement of compounds specifically designed to target ubiquitinates, offering promising prospects for cancer therapy. In this review, we highlight the role of ubiquitination enzymes associated with chemoresistance to chemotherapy via the Wnt/β-catenin signaling pathway, epithelial-mesenchymal transition (EMT), and cell cycle perturbation. In addition, we summarize the application and role of small compounds that target ubiquitination enzymes for CRC treatment, along with the significance of targeting ubiquitination enzymes as potential cancer therapies.

Wnt/β-catenin signalling activates IMPDH2-mediated purine metabolism to facilitate oxaliplatin resistance by inhibiting caspase-dependent apoptosis in colorectal cancer

BACKGROUND

Oxaliplatin resistance usually leads to therapeutic failure and poor prognosis in colorectal cancer (CRC), while the underlying mechanisms are not yet fully understood. Metabolic reprogramming is strongly linked to drug resistance, however, the role and mechanism of metabolic reprogramming in oxaliplatin resistance remain unclear. Here, we aim to explore the functions and mechanisms of purine metabolism on the oxaliplatin-induced apoptosis of CRC.

METHODS

An oxaliplatin-resistant CRC cell line was generated, and untargeted metabolomics analysis was conducted. The inosine 5'-monophosphate dehydrogenase type II (IMPDH2) expression in CRC cell lines was determined by quantitative real-time polymerase chain reaction (qPCR) and western blotting analysis. The effects of IMPDH2 overexpression, knockdown and pharmacological inhibition on oxaliplatin resistance in CRC were assessed by flow cytometry analysis of cell apoptosis in vivo and in vitro.

RESULTS

Metabolic analysis revealed that the levels of purine metabolites, especially guanosine monophosphate (GMP), were markedly elevated in oxaliplatin-resistant CRC cells. The accumulation of purine metabolites mainly arose from the upregulation of IMPDH2 expression. Gene set enrichment analysis (GSEA) indicated high IMPDH2 expression in CRC correlates with PURINE_METABOLISM and MULTIPLE-DRUG-RESISTANCE pathways. CRC cells with higher IMPDH2 expression were more resistant to oxaliplatin-induced apoptosis. Overexpression of IMPDH2 in CRC cells resulted in reduced cell death upon treatment with oxaliplatin, whereas knockdown of IMPDH2 led to increased sensitivity to oxaliplatin through influencing the activation of the Caspase 7/8/9 and PARP1 proteins on cell apoptosis. Targeted inhibition of IMPDH2 by mycophenolic acid (MPA) or mycophenolate mofetil (MMF) enhanced cell apoptosis in vitro and decreased in vivo tumour burden when combined with oxaliplatin treatment. Mechanistically, the Wnt/β-catenin signalling was hyperactivated in oxaliplatin-resistant CRC cells, and a reciprocal positive regulatory mechanism existed between Wnt/β-catenin and IMPDH2. Blocking the Wnt/β-catenin pathway could resensitize resistant cells to oxaliplatin, which could be restored by the addition of GMP.

CONCLUSIONS

IMPDH2 is a predictive biomarker and therapeutic target for oxaliplatin resistance in CRC.

CAF-derived exosomal lncRNA FAL1 promotes chemoresistance to oxaliplatin by regulating autophagy in colorectal cancer

Oxaliplatin is a widely applied anti-cancer drug in clinics for colorectal cancer (CRC) treatment. Nonetheless, the treatment efficacy is always limited by the acquisition of chemoresistance in cancer cells. The deregulation of long non-coding RNA (lncRNA) FAL1 has been implicated in the tumorigenesis and progression of different malignancies. Nevertheless, the possible contribution of lnc-FAL1 in drug resistance development of CRC has not been investigated. Here, we reported the overexpression of lnc-FAL1 in CRC samples, and elevated lnc-FAL1 levels seemed to be associated with the poor survival in CRC patients. We further demonstrated that lnc-FAL1 promoted oxaliplatin chemoresistance in both cell and animal model. Additionally, lnc-FAL1 was mainly derived from exosomes secreted by cancer associated fibroblasts (CAFs), and lnc-FAL1-containing exosomes or lnc-FAL1 overexpression significantly inhibited oxaliplatin-induced autophagy in CRC cells. Mechanistically, lnc-FAL1 acted as a scaffold for the interaction between Beclin1 and TRIM3 to promote TRIM3-dependent Beclin1 polyubiquitination and degradation, thereby suppressing oxaliplatin-induced autophagic cell death. In summary, these data imply a molecular mechanism through which CAF-derived exosomal lnc-FAL1 contributes to the acquisition of oxaliplatin resistance in CRC.

CYB5R1 is a potential biomarker that correlates with stemness and drug resistance in gastric cancer

BACKGROUND

Drug resistance is a major obstacle in the treatment of gastric cancers (GC). In recent years, the prognostic value of the mRNA expression-based stemness score (mRNAss) across cancers has been reported. We intended to search for the key genes associated with Cancer stem cells (CSCs) and drug resistance.

METHODS

All GC samples from The Cancer Genome Atlas (TCGA) were then divided into low- and high-mRNAss groups based on the median value of mRNAss. A weighted correlation network analysis (WCGNA) was used to identify co-expressed genes related to mRNAss groups. Differential gene expression analysis with Limma was performed in the GSE31811. The correlations between CYB5R1 and the immune cells and macrophage infiltration were analyzed by TIMER database. Spheroid formation assay was used to evaluate the stemness of gastric cancer cells, and transwell assay was used to detect the invasion and migration ability of gastric cancer cells.

RESULTS

GC patients with high mRNAss values had a worse prognosis than those with low mRNAss values. 584 genes were identified by WGCNA analysis. 668 differentially expressed genes (DEGs) (|logFC|>1) with 303 down-regulated and 365 up-regulated were established in drug-effective patients compared to controls. TCGA-STAD samples were divided into 3 subtypes based on 303 down-regulated genes. CYB5R1 was a potential biomarker that correlated with the response to drugs in GC (AUC=0.83). CYB5R1 participated in drug resistance and tumorigenesis through NFS1 in GC.

CONCLUSIONS

Our study highlights the clinical importance of CYB5R1 in GC and the CYB5R1-NFS1 signaling-targeted therapy might be a feasible strategy for the treatment of GC.

A potential therapeutic approach for gastric cancer: inhibition of LACTB transcript 1

BACKGROUND

This study sought to investigate the role of LACTB transcript 1 in regulating adaptive immune resistance and stemness in gastric cancer and its potential as a therapeutic target for precision medicine.

METHODS

Bioinformatics analysis and RT-qPCR were used to analyze the expression level of LACTB and its transcripts in gastric cancer cells. The effects of LACTB transcript 1 on adaptive immune resistance and stemness were evaluated using in vitro cell experiments and western blotting experiments.

RESULTS

Our study findings revealed that LACTB transcript 1 modulated adaptive immune resistance and inhibited the stemness of gastric cancer cells. Knocking down the expression level of LACTB transcript 1 activated autophagy and inhibited EMT. As expected, overexpression of LACTB transcript 1 yielded the opposite findings. The expression level of LACTB transcript 1 in the peripheral blood of gastric cancer patients was consistent with the bioinformatics analysis, suggesting its potential as a biomarker of gastric cancer.

CONCLUSIONS

LACTB transcript 1 is a promising therapeutic target for precision medicine in gastric cancer by modulating immune evasion mechanisms and stemness. These findings provide insights into leveraging long non-coding RNAs (lncRNAs) in immunotherapy, radiotherapy, and chemotherapy to enhance cancer therapy efficacy, particularly in the context of targeting tumor heterogeneity and stemness.

Pre-operative clonal hematopoiesis is related to adverse outcome in lung cancer after adjuvant therapy

BACKGROUND

Clonal hematopoiesis (CH) frequently progresses after chemotherapy or radiotherapy. We evaluated the clinical impact of preoperative CH on the survival outcomes of patients with non-small cell lung cancer (NSCLC) who underwent surgical resection followed by adjuvant therapy.

METHODS

A total of 415 consecutive patients with NSCLC who underwent surgery followed by adjuvant therapy from 2011 to 2017 were analyzed. CH status was evaluated using targeted deep sequencing of blood samples collected before surgery. To minimize the possible selection bias between the two groups according to CH status, a propensity score matching (PSM) was adopted. Early-stage patients were further analyzed with additional matched cohort of patients who did not receive adjuvant therapy.

RESULTS

CH was detected in 21% (86/415) of patients with NSCLC before adjuvant therapy. Patients with CH mutations had worse overall survival (OS) than those without (hazard ratio [95% confidence interval] = 1.56 [1.07-2.28], p = 0.020), which remained significant after the multivariable analysis (1.58 [1.08-2.32], p = 0.019). Of note, the presence of CH was associated with non-cancer mortality (p = 0.042) and mortality of unknown origin (p = 0.018). In patients with stage IIB NSCLC, there was a significant interaction on OS between CH and adjuvant therapy after the adjustment with several cofactors through the multivariable analysis (HR 1.19, 95% CI 1.00-1.1.41, p = 0.041).

CONCLUSIONS

In resected NSCLC, existence of preoperative CH might amplify CH-related adverse outcomes through adjuvant treatments, resulting in poor survival results.

Hydroxychloroquine-Loaded Chitosan Nanoparticles Induce Anticancer Activity in A549 Lung Cancer Cells: Design, BSA Binding, Molecular Docking, Mechanistic, and Biological Evaluation

The current study describes the encapsulation of hydroxychloroquine, widely used in traditional medicine due to its diverse pharmacological and medicinal uses, in chitosan nanoparticles (CNPs). This work aims to combine the HCQ drug with CS NPs to generate a novel nanocomposite with improved characteristics and bioavailability. HCQ@CS NPs are roughly shaped like roadways and have a smooth surface with an average size of 159.3 ± 7.1 nm, a PDI of 0.224 ± 0.101, and a zeta potential of +46.6 ± 0.8 mV. To aid in the development of pharmaceutical systems for use in cancer therapy, the binding mechanism and affinity of the interaction between HCQ and HCQ@CS NPs and BSA were examined using stopped-flow and other spectroscopic approaches, supplemented by molecular docking analysis. HCQ and HCQ@CS NPs binding with BSA is driven by a ground-state complex formation that may be accompanied by a non-radiative energy transfer process, and binding constants indicate that HCQ@CS NPs-BSA was more stable than HCQ-BSA. The stopped-flow analysis demonstrated that, in addition to increasing BSA affinity, the nanoformulation HCQ@CS NPS changes the binding process and may open new routes for interaction. Docking experiments verified the development of the HCQ-BSA complex, with HCQ binding to site I on the BSA structure, primarily with the amino acids, Thr 578, Gln 579, Gln 525, Tyr 400, and Asn 404. Furthermore, the nanoformulation HCQ@CS NPS not only increased cytotoxicity against the A549 lung cancer cell line (IC50 = 28.57 ± 1.72 μg/mL) compared to HCQ (102.21 ± 0.67 μg/mL), but also exhibited higher antibacterial activity against both Gram-positive and Gram-negative bacteria when compared to HCQ and chloramphenicol, which is in agreement with the binding constants. The nanoformulation developed in this study may offer a viable therapy option for A549 lung cancer.

Evaluation of toxicity and mutagenicity of oxaliplatin on germ cells in an alternative in vivo model Caenorhabditis elegans

The platinum compound oxaliplatin is a widely used chemotherapeutic drug that shows a broad spectrum of activity in various human tumors. While the treatment-related side effects of oxaliplatin on directly treated individuals have been well-documented, little is known about the influence of oxaliplatin on germ cells and non-exposed progenies. Here we investigated the reproductive toxicity of oxaliplatin in a 3R-compliant in vivo model Caenorhabditis elegans, and evaluated the germ cell mutagenicity of oxaliplatin by using whole genome sequencing. Our results indicated that oxaliplatin treatment significantly disrupts development of spermatids and oocytes. By treating parental worms with oxaliplatin for three successive generations, sequencing data unveiled the clear mutagenic effects of oxaliplatin on germ cells. Analysis of genome-wide mutation spectra showed the preferentially induction of indels by oxaliplatin. In addition, we uncovered the involvement of translesion synthesis polymerase ζ in modulating mutagenic effects of oxaliplatin. These findings suggest that germ cell mutagenicity is worthy of consideration for the health risk assessment of chemotherapeutic drugs, while the combined use of alternative in vivo models and next generation sequencing technology appears to be a promising way for the preliminary safety assessment of various drugs.

β-Lapachone Exerts Anticancer Effects by Downregulating p53, Lys-Acetylated Proteins, TrkA, p38 MAPK, SOD1, Caspase-2, CD44 and NPM in Oxaliplatin-Resistant HCT116 Colorectal Cancer Cells

β-lapachone (β-Lap), a topoisomerase inhibitor, is a naturally occurring ortho-naphthoquinone phytochemical and is involved in drug resistance mechanisms. Oxaliplatin (OxPt) is a commonly used chemotherapeutic drug for metastatic colorectal cancer, and OxPt-induced drug resistance remains to be solved to increase chances of successful therapy. To reveal the novel role of β-Lap associated with OxPt resistance, 5 μM OxPt-resistant HCT116 cells (HCT116-OxPt-R) were generated and characterized via hematoxylin staining, a CCK-8 assay and Western blot analysis. HCT116-OxPt-R cells were shown to have OxPt-specific resistance, increased aggresomes, upregulated p53 and downregulated caspase-9 and XIAP. Through signaling explorer antibody array, nucleophosmin (NPM), CD37, Nkx-2.5, SOD1, H2B, calreticulin, p38 MAPK, caspase-2, cadherin-9, MMP23B, ACOT2, Lys-acetylated proteins, COL3A1, TrkA, MPS-1, CD44, ITGA5, claudin-3, parkin and ACTG2 were identified as OxPt-R-related proteins due to a more than two-fold alteration in protein status. Gene ontology analysis suggested that TrkA, Nkx-2.5 and SOD1 were related to certain aggresomes produced in HCT116-OxPt-R cells. Moreover, β-Lap exerted more cytotoxicity and morphological changes in HCT116-OxPt-R cells than in HCT116 cells through the downregulation of p53, Lys-acetylated proteins, TrkA, p38 MAPK, SOD1, caspase-2, CD44 and NPM. Our results indicate that β-Lap could be used as an alternative drug to overcome the upregulated p53-containing OxPt-R caused by various OxPt-containing chemotherapies.

Association of variations in the CAT and prognosis in lung cancer patients with platinum-based chemotherapy

PURPOSE: To explore the relationship between ATM, ATR and CAT polymorphisms and prognosis of lung cancer patients received platinum-based chemotherapy.

METHODS: 404 patients with lung cancer who received platinum-chemotherapy were enrolled and DNA typing was performed. Cox regression analysis and stratification analyses was performed to assess relationships between OS and PFS with SNPs genotypes. The prognosis of lung adenocarcinomaand squamous cell carcinomapatients was analyzed with The Cancer Genome Atlas (TCGA) database according to the grouping of CAT expression.

RESULTS:CAT rs769217 was significantly related to PFS of patients with lung cancer who received platinum-chemotherapy. In the Additive model, rs769217 was associated with PFS (HR = 0.747, 95% CI = 0.581–0.960, p = 0.023). In the Dominant model, CT and TT genotypes led to lung cancer progression 0.738 times more than CC genotype. In stratification analyses of association between CAT rs769217 polymorphisms and PFS, the HR of patients at stage IV in additive model was 0.73, and HR was 0.745 (p = 0.034) in dominant model. For OS analyses, HR was 0.672 in the older lung cancer patients (>55 years old) in additive model. Meanwhile, in the Dominant model, it was found that the older patients with CT and TT genotypes had better prognosis, and the risk of death after receiving platinum-based chemotherapy was 0.692 times that of patients with CC genotype (p = 0.037). TCGA data shows that LUAD patients with high CAT expression have longer OS (p = 0.020).

CONCLUSION:CAT rs769217 is significantly related to PSF of platinum-based chemotherapy in lung cancer patients and may be a biomarker for predicting the prognosis of lung cancer patients with platinum-based chemotherapy.

Hirsutidin Prevents Cisplatin-Evoked Renal Toxicity by Reducing Oxidative Stress/Inflammation and Restoring the Endogenous Enzymatic and Non-Enzymatic Level

Recent research has shown that phytocomponents may be useful in the treatment of renal toxicity. This study was conducted to evaluate the renal disease hirsutidin in the paradigm of renal toxicity induced by cisplatin. Male Wistar rats were given cisplatin (3 mg/kg body weight/day, for 25 days, i.p.) to induce renal toxicity. Experimental rats were randomly allocated to four different groups: group I received saline, group II received cisplatin, group III received cisplatin + hirsutidin (10 mg/kg)and group IV (per se)received hirsutidin (10 m/kg)for 25 days. Various biochemical parameters were assessed, oxidative stress (superoxide dismutase (SOD), glutathione transferase (GSH), malonaldehyde (MDA) and catalase (CAT)), blood-chemistry parameters (blood urea nitrogen (BUN) and cholesterol), non-protein-nitrogenous components (uric acid, urea, and creatinine), and anti-inflammatory-tumor necrosis factor-α (TNF-α), interleukin-1β(IL-1β). IL-6 and nuclear factor-kB (NFκB) were evaluated and histopathology was conducted. Hirsutidin alleviated renal injury which was manifested by significantly diminished uric acid, urea, urine volume, creatinine, and BUN, compared to the cisplatin group. Hirsutidin restored the activities of several antioxidant enzyme parameters—MDA, CAT, GSH, and SOD. Additionally, there was a decline in the levels of inflammatory markers—TNF-α, IL-1β, IL-6, and NFκB—compared to the cisplatin group. The current research study shows that hirsutidin may act as a therapeutic agent for the treatment of nephrotoxicity induced by cisplatin.

Echinatin induces reactive oxygen species-mediated apoptosis via JNK/p38 MAPK signaling pathway in colorectal cancer cells

Colorectal cancer (CRC) is a very common and deadly cancer worldwide, and oxaliplatin is used as first-line chemotherapy. However, resistance usually develops, limiting treatment. Echinatin (Ech) is the main component of licorice and exhibits various therapeutic effects on inflammation-mediated diseases and cancer, ischemia/reperfusion, and liver injuries. The present study elucidated the underlying molecular mechanism of Ech-induced apoptosis in both oxaliplatin-sensitive (HT116 and HT29) and -resistant (HCT116-OxR and HT29-OxR) CRC cells. To evaluate the antiproliferative activities of Ech, we performed MTT and soft agar assays. Ech reduced viability, colony size, and numbers of CRC cells. The underlying molecular mechanisms were explored by various flow cytometry analyses. Ech-induced annexin-V stained cells, reactive oxygen species (ROS) generation, cell cycle arrest, JNK/p38 MAPK activation, endoplasmic reticulum (ER) stress, mitochondrial membrane potential depolarization, and multi-caspase activity. In addition apoptosis-, cell cycle-, and ER stress-related protein levels were confirmed by western blotting. Moreover, we verified ROS-mediated cell death by treatment with inhibitors such as N-acetyl-L-cysteine, SP600125, and SB203580. Taken together, Ech exhibits anticancer activity in oxaliplatin-sensitive and -resistant CRCs by inducing ROS-mediated apoptosis through the JNK/p38 MAPK signaling pathway. This is the first study to show that Ech has the potential to treat drug-resistant CRC, providing new directions for therapeutic strategies targeting drug-resistant CRC.

Will the Interactions of Some Platinum (II)-Based Drugs with B-Vitamins Reduce Their Therapeutic Effect in Cancer Patients? Comparison of Chemotherapeutic Agents such as Cisplatin, Carboplatin and Oxaliplatin-A Review

Pt (II) derivatives show anti-cancer activity by interacting with nucleobases of DNA, thus causing some spontaneous and non-spontaneous reactions. As a result, mono- and diaqua products are formed which further undergo complexation with guanine or adenine. Consequently, many processes are triggered, which lead to the death of the cancer cell. The theoretical and experimental studies confirm that such types of interactions can also occur with other chemical compounds. The vitamins from B group have a similar structure to the nucleobases of DNA and have aromatic rings with single-pair orbitals. Theoretical and experimental studies were performed to describe the interactions of B vitamins with Pt (II) derivatives such as cisplatin, oxaliplatin and carboplatin. The obtained results were compared with the values for guanine. Two levels of simulations were implemented at the theoretical level, namely, B3LYP/6-31G(d,p) with LANL2DZ bases set for platinum atoms and MN15/def2-TZVP. The polarizable continuum model (IEF-PCM preparation) and water as a solvent were used. UV-Vis spectroscopy was used to describe the drug-nucleobase and drug-B vitamin interactions. Values of the free energy (ΔG_r) show spontaneous reactions with mono- and diaqua derivatives of cisplatin and oxaliplatin; however, interactions with diaqua derivatives are more preferable. The strength of these interactions was also compared. Carboplatin products have the weakest interaction with the studied structures. The presence of non-covalent interactions was demonstrated in the tested complexes. A good agreement between theory and experiment was also demonstrated.

Trans-[bis(benzimidazol-2-ylidene)dichlorido]platinum(II) complexes with peculiar modes of action and activity against cisplatin-resistant cancer cells

Three series of cis- and trans-[bis(benzimidazol-2-ylidene)dichlorido]platinum(II) and cis-[(benzimidazol-2-ylidene)(DMSO)dichlorido]platinum(II) complexes were synthesised and screened for cytotoxicity against six human cancer cell lines. Depending on their N-alkyl and 5-alkoxycarbonyl substituents, two-digit nanomolar to single-digit micromolar IC₅₀ values against cancer cell lines intrinsically resistant to or ill-responding to cisplatin were reached by both cis- and trans-configured complexes. The stability of the complexes under aqueous biotest conditions was shown via ¹H and ¹⁹⁵Pt NMR monitoring to be dependent on their configuration and their N-substituents. Localisation studies employing click reactions with 1-alkyne- or cyclopropene-tagged derivatives revealed that the cis-complexes accumulated in the cell nuclei and the trans-complexes in the mitochondria. While the most active cis-complexes showed modes of action akin to those of cisplatin, the most active trans-complexes differed from cisplatin by much lower rates of cellular uptake and ROS production, and by their non-interaction with the cell cycle and the DNA of cancer cells. Thus, we identified structural key elements for the synthesis of optimised trans-configured NHC platinum(II) complexes with high activity also against cisplatin-refractory cancer cells.

LINC01615 maintains cell survival in adaptation to nutrient starvation through the pentose phosphate pathway and modulates chemosensitivity in colorectal cancer

Numerous mechanisms involved in promoting cancer cell survival under nutrient starvation have been described. Long noncoding RNAs (lncRNAs) have emerged as critical players in colorectal cancer (CRC) progression, but the role of lncRNAs in the progression of CRC under nutrient starvation has not been well clarified. Here, we identified a lncRNA, LINC01615, that was significantly upregulated in response to serum starvation. LINC01615 can contribute to the adaptation of CRC cells to serum-deprived conditions and enhance cell survival under similar conditions. LINC01615 activated the pentose phosphate pathway (PPP) under serum starvation, manifested as decreased ROS production and enhanced nucleotide and lipid synthesis. Glucose-6-phosphate dehydrogenase (G6PD) is a key rate-limiting enzyme of the PPP, and LINC01615 promoted G6PD expression by competitively binding with hnRNPA1 and facilitating G6PD pre-mRNA splicing. Moreover, we also found that serum starvation led to METTL3 degradation by inducing autophagy, which further increased the stability and level of LINC01615 in a m6A-dependent manner. LINC01615 knockdown combined with oxaliplatin achieved remarkable antitumor effects in PDO and PDX models. Collectively, our results demonstrated a novel adaptive survival mechanism permitting tumor cells to survive under limiting nutrient supplies and provided a potential therapeutic target for CRC.

Revisiting the Anti-Cancer Toxicity of Clinically Approved Platinating Derivatives

Cisplatin (CDDP), carboplatin (CP), and oxaliplatin (OXP) are three platinating agents clinically approved worldwide for use against a variety of cancers. They are canonically known as DNA damage inducers; however, that is only one of their mechanisms of cytotoxicity. CDDP mediates its effects through DNA damage-induced transcription inhibition and apoptotic signalling. In addition, CDDP targets the endoplasmic reticulum (ER) to induce ER stress, the mitochondria via mitochondrial DNA damage leading to ROS production, and the plasma membrane and cytoskeletal components. CP acts in a similar fashion to CDDP by inducing DNA damage, mitochondrial damage, and ER stress. Additionally, CP is also able to upregulate micro-RNA activity, enhancing intrinsic apoptosis. OXP, on the other hand, at first induces damage to all the same targets as CDDP and CP, yet it is also capable of inducing immunogenic cell death via ER stress and can decrease ribosome biogenesis through its nucleolar effects. In this comprehensive review, we provide detailed mechanisms of action for the three platinating agents, going beyond their nuclear effects to include their cytoplasmic impact within cancer cells. In addition, we cover their current clinical use and limitations, including side effects and mechanisms of resistance.

In vitro and In vivo Studies of Potential Anticancer Agents of Platinum(II) Complexes of Dicyclopentadiene and Dithiocarbamates

Three platinum(II) complexes of dicyclopentadiene (DCP) and dithiocarbamates (DTC), namely, [Pt(η4-DCP)(Me2DTC)]PF6 (1), [Pt(η4-DCP)(Et2DTC)]PF6 (2) and [Pt(η4-DCP)(Bz2DTC)]PF6 (3) [Me2DTC = dimethyldithiocarbamate, Et2DTC = diethyldithiocarbamate, and Bz2DTC = dibenzyldithiocarbamate] were prepared and characterized by elemental analysis, IR, 1H and 13C NMR spectroscopy. The spectroscopic data indicated the coordination of both DCP and dithiocarbamate ligands to platinum(II). The solution chemisty of complex 1 revealed that the complexes are stable in both DMSO and 1:1 mixture of DMSO: H2O. In vitro cytotoxicity of the complexes relative to cisplatin was tested using MTT assay, against CHL-1 (human melanoma cancer cells), MDA-MB-231 (breast cancer cells), A549 (lung cancer cells), and B16 (murine melanoma cancer cells). The antiproliferative effect of all three prepared complexes was found to be significantly higher than cisplatin. Furthermore, flow cytometric analysis of complex 1 showed that the complex induced apoptosis, oxidative stress, mitochondrial potential depolarization and cell cycle arrest in a concentration-dependent pattern in the CHL-1 cells. Confirmation of apoptosis via gene expression analysis demonstrated down-regulation of anti-apoptotic genes and up-regulation of pro-apoptotic genes in the CHL-1 cells. Wound healing assays also lent support to the strong cytotoxicity of the complexes. In vivo studies showed a significant reduction of tumor volume at the end of the experiment. In addition, the drug did not change the weight of the mice. In conclusion, complex 1 inhibited cell proliferation in vitro and reduced tumor growth in vivo.

Synergistic effects of natural compounds and conventional chemotherapeutic agents: recent insights for the development of cancer treatment strategies

Cancer is one of the leading causes of death in the world. Chemotherapy is presented as an option for treatment of this disease, however, low specificity, high resistance rates, toxicity and hypersensitivity reactions, make it necessary to search for therapeutic alternatives that increase the selectivity of treatment, reduce the side effects and enhance its antitumor potential. Natural products are accessible, inexpensive and less toxic sources; in addition, they have multiple mechanisms of action that can potentiate the outcome of chemotherapeutics. In this review, we present evidence on the beneficial effect of the interaction of dietary phytochemicals with chemotherapeutical agents for cancer treatment. This effect is generated by different mechanisms of action such as, increased tumoricidal effect via sensitization of cancer cells, reversing chemoresistance through inhibition of several targets involved in the development of drug resistance and, decreasing chemotherapy-induced toxicity in non-tumoral cells by the promotion of repair mechanisms. Studies discussed in this review will provide a solid basis for the exploration of the potential use of natural products in combination with chemotherapeutical agents, to overcome some of the difficulties that arise in the management of cancer patients.

Nanocarrier System for Increasing the Therapeutic Efficacy of Oxaliplatin

The application of Oxaliplatin (OxPt) in different malignancies is reported to be accompanied by several side effects including neuropathy, nausea, vomiting, diarrhea, mouth sores, low blood counts, loss of appetite, etc. The passive or active targeting of different tumors can improve OxPt delivery. Considering the demand for novel systems meant to improve the OxPt efficacy and define the shortcomings, we provided an overview of different approaches regarding the delivery of OxPt. There is an extending body of data that exhibits the value of Liposomes and polymer-based drug delivery systems as the most successful systems among the OxPt drug delivery procedures. Several clinical trials have been carried out to investigate the side effects and dose-limiting toxicity of liposomal oxaliplatin such as the assessment on Safety Study of MBP-426 (Liposomal Oxaliplatin Suspension for Injection) to Treat Advanced or Metastatic Solid Tumors. In addition, several studies indicated the biocompatibility and biodegradability of this product, as well as its option for being fictionalized to derive specialized smart nanosystems for the treatment of cancer. The better delivery of OxPt with weaker side effects could be generated by the exertion of Oxaliplatin, which involves the aggregation of new particles and multifaceted nanocarriers to compose a nanocomposite with both inorganic and organic nanoparticles.

Impact of cisplatin administration on cerebellar cortical structure and locomotor activity of infantile and juvenile albino rats: the role of oxidative stress

The central neurotoxicity of cisplatin (CisPt) has always raised questions especially during development, but few studies are available. Hence, this work was designed to assess the CisPt's impacts on the postnatal rat cerebellum via evaluation of locomotor activity, histological and immunohistochemical studies, and to focus on cerebellar oxidative stress-related alterations. Eighty newborn pups were divided into 2 equal experimental groups: the control group was kept without any treatment and CisPt-treated group received a single subcutaneous injection of CisPt (5 μg /g b.w.) in their nape at PD10. Ten rats at PD11, PD17, and PD30 ages were weighed, then deeply anesthetized and sacrificed. For locomotor assessment, 20 pups were divided equally into control and CisPt-treated groups and tested at PD11-13, PD15-17, and PD28-30 ages. CisPt-treated rats suffered from decreased motor activity and showed decreased body and cerebellar weights, reduced levels of enzymatic antioxidants (SOD and CAT), and non-enzymatic antioxidant defense (GSH), and increase of lipid peroxidation marker (MDA). Histopathologically, CisPt sowed deleterious changes within cerebellar cortical layers in the form of vacuolations, decreased thickness, and hemorrhage (in PD17), while Purkinje cells exhibited profound degenerative changes in the form of swelling, disrupted arrangement, distortion, and nuclear shrinkage. In CisPt-treated rats, GFAP demonstrated upregulated, hypertrophied, and branched Bergmann glial fibers and reactive astrogliosis. Immuno-localization of Ki-67-positive cells revealed defective migration associated with decreased proliferation in early ages in addition to glial proliferation in PD30. In conclusion, CisPt causes oxidative stress-related deleterious effects on structure of developing cerebellar cortex and affects locomotor activity.

Targeting hexokinase 2 increases the sensitivity of oxaliplatin by Twist1 in colorectal cancer

Colorectal cancer (CRC) is the third most malignant tumour worldwide, with high mortality and recurrence. Chemoresistance is one of the main factors leading to metastasis and poor prognosis in advanced CRC patients. By analysing the Gene Expression Omnibus data set, we found higher hexokinase 2 (HK2) expression levels in patients with metastatic CRC than in those with primary CRC. Moreover, we observed higher enrichment in oxaliplatin resistance‐related gene sets in metastatic CRC than in primary CRC. However, the underlying relationship has not yet been elucidated. In our study, HK2 expression was significantly elevated in CRC patients. Gene set enrichment analysis (GSEA) revealed multi‐drug resistance and epithelial‐mesenchymal transition (EMT) pathways related to high HK2 expression. Our results showed that knockdown of HK2 significantly inhibited vimentin and Twist1 expression and promoted TJP1 and E‐cadherin expression in CRC cells. Additionally, transcriptional and enzymatic inhibition of HK2 by 3‐bromopyruvate (3‐bp) impaired oxaliplatin resistance in vitro and in vivo. Mechanistically, HK2 interacts with and stabilized Twist1 by preventing its ubiquitin‐mediated degradation, which is related to oxaliplatin resistance, in CRC cells. Overexpression of Twist1 reduced the apoptosis rate by HK2 knockdown in CRC cells. Collectively, we discovered that HK2 is a crucial regulator that mediates oxaliplatin resistance through Twist1. These findings identify HK2 and Twist1 as promising drug targets for CRC chemoresistance.

Lipid, polymeric, inorganic-based drug delivery applications for platinum-based anticancer drugs

The three main FDA-approved platinum drugs in chemotherapy such as carboplatin, cisplatin, and oxaliplatin are extensively applied in cancer treatments. Although the clinical applications of platinum-based drugs are extremely effective, their toxicity profile restricts their extensive application. Therefore, recent studies focus on developing new platinum drug formulations, expanding the therapeutic aspect. In this sense, recent advances in the development of novel drug delivery carriers will help with the increase of drug stability and biodisponibility, concomitantly with the reduction of drug efflux and undesirable secondary toxic effects of platinum compounds. The present review describes the state of the art of platinum drugs with their biological effects, pre- and clinical studies, and novel drug delivery nanodevices based on lipids, polymers, and inorganic.

Role of FOXO protein's abnormal activation through PI3K/AKT pathway in platinum resistance of ovarian cancer

AIM

Platinum-based chemotherapy is the standard treatment for ovarian cancer. However, tumor cells' resistance to platinum drugs often occurs. This paper provides a review of Forkhead box O (FOXO) protein's role in platinum resistance of ovarian cancer which hopefully may provide some further guidance for the treatment of platinum-resistant ovarian cancer.

METHODS

We reviewed a 128 published papers from authoritative and professional journals on FOXO and platinum-resistant ovarian cancer, and adopts qualitative analyses and interpretation based on the literature.

RESULTS

Ovarian cancer often has abnormal activation of cellular pathways, the most important of which is the PI3K/AKT pathway. FOXOs act as crucial downstream factor of the PI3K/Akt pathway and are negatively regulated by it. DNA damage response and apoptosis including the relationship between FOXOs and ATM-Chk2-p53 are essential for platinum resistance of ovarian cancer. Through gene expression analysis in platinum-resistant ovarian cancer cell model, it was found that FoxO-1 is decreased in platinum-resistant ovarian cancer, so studying the role of FOXO in the pathway on platinum-induced apoptosis may further guide the treatment of platinum-resistant ovarian cancer.

CONCLUSIONS

There are many drug resistance mechanisms in ovarian cancer, wherein the decrease in cancer cells apoptosis is one of the important causes. Constituted by a series of transcription factors evolving conservatively and mainly working in inhibiting cancer, FOXO proteins play various roles in cells' antitumor response. More and more evidence suggests that we need to re-understand the role that FOXOs have played in cancer development and treatment.

The Mechanistic Roles of ncRNAs in Promoting and Supporting Chemoresistance of Colorectal Cancer

Colorectal Cancer (CRC) is one of the most common gastrointestinal malignancies which has quite a high mortality rate. Despite the advances made in CRC treatment, effective therapy is still quite challenging, particularly due to resistance arising throughout the treatment regimen. Several studies have been carried out to identify CRC chemoresistance mechanisms, with research showing different signalling pathways, certain ATP binding cassette (ABC) transporters and epithelial mesenchymal transition (EMT), among others to be responsible for the failure of CRC chemotherapies. In the last decade, it has become increasingly evident that certain non-coding RNA (ncRNA) families are involved in chemoresistance. Research investigations have demonstrated that dysregulation of microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) contribute towards promoting resistance in CRC via different mechanisms. Considering the currently available data on this phenomenon, a better understanding of how these ncRNAs participate in chemoresistance can lead to suitable solutions to overcome this problem in CRC. This review will first focus on discussing the different mechanisms of CRC resistance identified so far. The focus will then shift onto the roles of miRNAs, lncRNAs and circRNAs in promoting 5-fluorouracil (5-FU), oxaliplatin (OXA), cisplatin and doxorubicin (DOX) resistance in CRC, specifically using ncRNAs which have been recently identified and validated under in vivo or in vitro conditions.

1,3-Diazepine: A privileged scaffold in medicinal chemistry

Privileged structures have been widely used as effective templates for drug discovery. While benzo-1,4-diazepine constitutes the first historical example of such a structure, the 1,3 analogue is just as rich in terms of applications in medicinal chemistry. The 1,3-diazepine moiety is present in numerous biological active compounds including natural products, and is used to design compounds displaying a large range of biological activities. It is present in the clinically used anticancer compound pentostatin, in several recent FDA approved β-lactamase inhibitors (e.g., avibactam) and also in coformycin, a natural product known as a ring-expanded purine analogue displaying antiviral and anticancer activities. Several other 1,3-diazepine containing compounds have entered into clinical trials. This heterocyclic structure has been and is still widely used in medicinal chemistry to design enzyme inhibitors, GPCR ligands, and so forth. This review endeavours to highlight the main use of the 1,3-diazepine scaffold and its derivatives, and their applications in medicinal chemistry, drug design, and therapy. We will focus more particularly on the development of enzyme inhibitors incorporating this scaffold, with a strong emphasis on the molecular interactions involved in the inhibition mechanism.

Elevating H3K27me3 level sensitizes colorectal cancer to oxaliplatin

Histone methylation is a context-dependent modification that regulates gene expression, and the trimethylation of histone H3 lysine 27 (H3K27me3) usually induces gene silencing. Overcoming colorectal cancer (CRC) chemoresistance is currently a huge challenge, but the relationship between H3K27me3 modification and chemoresistance remains largely unclear. Here, we found that H3K27me3 levels positively correlated with the metastasis-free survival of CRC patients and a low H3K27me3 level predicted a poor outcome upon chemotherapeutic drug treatment. Oxaliplatin stimulation significantly induced the expression of H3K27 lysine demethylase 6A/6B (KDM6A/6B), thus decreasing the level of H3K27me3 in CRC cells. Elevation of H3K27me3 level through KDM6A/6B depletion or GSK-J4 (a KDM6A/6B inhibitor) treatment significantly enhanced oxaliplatin-induced apoptosis. Conversely, when inhibiting the expression of H3K27me3 by EPZ-6438, an inhibitor of the histone methyltransferase EZH2, the proportion of apoptotic cells remarkably decreased. In addition, the combination of GSK-J4 and oxaliplatin significantly inhibited tumor growth in an oxaliplatin-resistant patient-derived xenograft model. Importantly, we revealed that oxaliplatin treatment dramatically induced NOTCH2 expression, which was caused by downregulation of H3K27me3 level on the NOTCH2 transcription initiation site. Thus, the activated NOTCH signaling promoted the expression of stemness-related genes, which resulted in oxaliplatin resistance. Furthermore, oxaliplatin-induced NOTCH signaling could be interrupted by GSK-J4 treatment. Collectively, our findings suggest that elevating H3K27me3 level can improve drug sensitivity in CRC patients.

Oxaliplatin derived monofunctional triazole-containing platinum(II) complex counteracts oxaliplatin-induced drug resistance in colorectal cancer

Oxaliplatin-based chemotherapy is the current standard of care in adjuvant therapy for advanced colorectal cancer (CRC). But acquired resistance to oxaliplatin eventually occurs and becoming a major cause of treatment failure. Thus, there is an unmet need for developing new chemical entities (NCE) as new therapeutic candidates to target chemotherapy-resistant CRC. Novel Pt(II) complexes were designed and synthesized as cationic monofunctional oxaliplatin derivatives for DNA platination-mediated tumor targeting. The complex Ph-glu-Oxa sharing the same chelating ligand of diaminocyclohexane (DACH) with oxaliplatin but is equally potent in inhibiting the proliferation of HT29 colon cancer cells and its oxaliplatin-resistant phenotype of HT29/Oxa. The in vivo therapeutic potential of Ph-glu-Oxa was confirmed in oxaliplatin-resistant xenograft model demonstrating the reversibility of the drug resistance by the new complex and the efficacy was associated with the unimpaired high intracellular drug accumulation in HT29/Oxa. Guanosine-5'-monophosphate (5'-GMP) reactivity, double-strand plasmid DNA cleavage, DNA-intercalated ethidium bromide (EB) fluorescence quenching and atomic force microscopy (AFM)-mediated DNA denaturing studies revealed that Ph-glu-Oxa was intrinsically active as DNA-targeting agent. The diminished susceptibility of the complex to glutathione (GSH)-mediated detoxification, which confers high intracellular accumulation of the drug molecule may play a key role in maintaining cytotoxicity and counteracting oxaliplatin drug resistance.

The influence of genetic polymorphisms on the toxicity of platinum-based chemotherapy in the treatment of non-small cell lung cancer

Lung cancer remains one of the most frequent and the deadliest of malignant diseases throughout the world. Target and immune therapy have revolutionalized the treatment of this disease, but platinum-based chemotherapy still has a place in the treatment algorithm. The toxicity profile of cisplatin is well known and can be a limiting factor in the adequate treatment delivery of the drug. There are important inter-individual differences in the efficacy and the toxicity of all chemotherapy drugs, which cannot be explained solely by the characteristics of the tumor. In order to define predictive factors for the occurrence of toxic effects, numerous genetic alterations have been investigated - especially single nucleotide polymorphisms (SNPs). The investigated genes are those involved in DNA repair mechanisms, signal pathways of apoptosis, DNA synthesis, transport mechanisms, but often with inconclusive and opposing results. It is clear that the effect of SNPs on the occurrence of cisplatin toxicity cannot be explained by investigating just one or several genes alone, but epigenetic interactions must be investigated, as well as interactions with outside factors. The study of SNPs is, however, a relatively simple and inexpensive method and, as such, can be used as one of the prognostic tools for everyday practice.

SASH1 is a prognostic indicator and potential therapeutic target in non-small cell lung cancer

SASH1 (SAM and SH3 domain-containing protein 1) is a tumor suppressor protein that has roles in key cellular processes including apoptosis and cellular proliferation. As these cellular processes are frequently disrupted in human tumours and little is known about the role of SASH1 in the pathogenesis of the disease, we analysed the prognostic value of SASH1 in non-small cell lung cancers using publicly available datasets. Here, we show that low SASH1 mRNA expression is associated with poor survival in adenocarcinoma. Supporting this, modulation of SASH1 levels in a panel of lung cancer cell lines mediated changes in cellular proliferation and sensitivity to cisplatin. The treatment of lung cancer cells with chloropyramine, a compound that increases SASH1 protein concentrations, reduced cellular proliferation and increased sensitivity to cisplatin in a SASH1-dependent manner. In summary, compounds that increase SASH1 protein levels could represent a novel approach to treat NSCLC and warrant further study.

Metalloproteomics for molecular target identification of protein-binding anticancer metallodrugs

Proteomics has played an important role in elucidating the fundamental processes occuring in living cells. Translating these methods to metallodrug research ('metalloproteomics') has provided a means for molecular target identification of metal-based anticancer agents which should signifcantly advance the research field. In combination with biological assays, these techniques have enabled the mechanisms of action of metallodrugs to be linked to their interactions with molecular targets and aid understanding of their biological properties. Such investigations have profoundly increased our knowledge of the complex and dynamic nature of metallodrug-biomolecule interactions and have provided, at least for some compound types, a more detailed picture on their specific protein-binding patterns. This perspective highlights the progression of metallodrug proteomics research for the identification of non-DNA targets from standard analytical techniques to powerful metallodrug pull-down methods.

Identification of biomarkers predicting the chemotherapeutic outcomes of capecitabine and oxaliplatin in patients with gastric cancer

The capecitabine and oxaliplatin (CapeOX) regimen is a commonly used adjuvant chemotherapeutic regimen for gastric cancer (GC). However, some patients exhibit a poor chemotherapy response due to genetic differences among individuals. Therefore, finding an effective sensitization strategy for CapeOX is important in the treatment of GC. The present study aimed to investigate the predictive biomarkers of the CapeOX chemotherapeutic outcomes for patients with GC. A total of 30 differentially expressed genes (DEGs) were identified using the gene expression profiles from The Cancer Genome Atlas capecitabine and oxaliplatin treatment GC cases and seven key DEGs [uroplakin-1b (UPK1B), fatty acid-binding protein, heart (FABP3), cystatin-M, caspase-5 (CASP5), corticosteroid 11-β-dehydrogenase isozyme 2, cytochrome P450 4X1 (CYP4X1) and epidermal growth factor receptor kinase substrate 8-like protein 3] were associated with survival. Gene validation was performed in clinical samples divided into recurrence and nonrecurrence groups. Patients with high or low expression of UPK1B, FABP3, CASP5 and CYP4X1 had markedly different overall survival rates. A model was established and the area under the curve of the receiver operating characteristic reached 0.875 (0.793–0.957), indicating that the model had good sensitivity and specificity.

Ascorbate sensitizes human osteosarcoma cells to the cytostatic effects of cisplatin

Osteosarcoma (OS) is the most common malignant bone tumor and a leading cause of cancer-related deaths in children and adolescents. Current standard treatments for OS are a combination of preoperative chemotherapy, surgical resection, and adjuvant chemotherapy. Cisplatin is used as the standard chemotherapeutic for OS treatment, but it induces various adverse effects, limiting its clinical application. Improving treatment efficacy without increasing the cisplatin dosage is desirable. In the present study, we assessed the combined effect of ascorbate on cisplatin treatment using cultured human OS cells. Co-treatment with ascorbate induced greater suppression of OS cell but not nonmalignant cell proliferation. The chemosensitizing effect of ascorbate on cisplatin treatment was tightly linked to ROS production. Altered cellular redox state due to increased ROS production modified glycolysis and mitochondrial function in OS cells. In addition, OS cell sphere formation was markedly decreased, suggesting that ascorbate increased the treatment efficacy of cisplatin against stem-like cells in the cancer cell population. We also found that enhanced MYC signaling, ribosomal biogenesis, glycolysis, and mitochondrial respiration are key signatures in OS cells with cisplatin resistance. Furthermore, cisplatin resistance was reversed by ascorbate. Taken together, our findings provide a rationale for combining cisplatin with ascorbate in therapeutic strategies against OS.

The Therapeutic Potential of DNA Damage Repair Pathways and Genomic Stability in Lung Cancer

Despite advances in our understanding of the molecular biology of the disease and improved therapeutics, lung cancer remains the most common cause of cancer-related deaths worldwide. Therefore, an unmet need remains for improved treatments, especially in advanced stage disease. Genomic instability is a universal hallmark of all cancers. Many of the most commonly prescribed chemotherapeutics, including platinum-based compounds such as cisplatin, target the characteristic genomic instability of tumors by directly damaging the DNA. Chemotherapies are designed to selectively target rapidly dividing cells, where they cause critical DNA damage and subsequent cell death (1, 2). Despite the initial efficacy of these drugs, the development of chemotherapy resistant tumors remains the primary concern for treatment of all lung cancer patients. The correct functioning of the DNA damage repair machinery is essential to ensure the maintenance of normal cycling cells. Dysregulation of these pathways promotes the accumulation of mutations which increase the potential of malignancy. Following the development of the initial malignancy, the continued disruption of the DNA repair machinery may result in the further progression of metastatic disease. Lung cancer is recognized as one of the most genomically unstable cancers (3). In this review, we present an overview of the DNA damage repair pathways and their contributions to lung cancer disease occurrence and progression. We conclude with an overview of current targeted lung cancer treatments and their evolution toward combination therapies, including chemotherapy with immunotherapies and antibody-drug conjugates and the mechanisms by which they target DNA damage repair pathways.

Inhibiting Importin 4-mediated nuclear import of CEBPD enhances chemosensitivity by repression of PRKDC-driven DNA damage repair in cervical cancer

Cervical cancer (CC) remains highest in the mortality of female reproductive system cancers, while cisplatin (CDDP) resistance is the one of main reasons for the lethality. Preceding evidence has supported that karyopherins are associated with chemoresistance. In this study, we simultaneously compared CDDP-incomplete responders with CDDP-complete responders of CC patients and CDDP‐insensitive CC cell lines with CDDP‐sensitive group. We finally identified that DNA-PKcs (PRKDC) was related to CDDP sensitivity after overlapping in CC sample tissues and CC cell lines. Further functional assay revealed that targeting PRKDC by shRNA and NU7026 (specific PRKDC inhibitor) could enhance CDDP sensitivity in vitro and in vivo, which was mediated by impairing DNA damage repair pathway in CC. Mechanistically, we found that PRKDC was transcriptionally upregulated by CCAAT/enhancer-binding protein delta (CEBPD), while intriguingly, CDDP treatment strengthened the transcriptional activity of CEBPD to PRKDC. We further disclosed that Importin 4 (IPO4) augmented the nuclear translocation of CEBPD through nuclear localization signals (NLS) to activate PRKDC-mediated DNA damage repair in response to CDDP. Moreover, we demonstrated that IPO4 and CEBPD knockdown improved CDDP-induced cytotoxicity in vitro and in vivo. Together, we shed the novel insight into the role of IPO4 in chemosensitivity and provide a clinical translational potential to enhance CC chemosensitivity since the IPO4-CEBPD-PRKDC axis is actionable via NU7026 (PRKDC inhibitor) or targeting IPO4 in combination with CDDP.

Ginkgo biloba Alleviates Cisplatin-Mediated Neurotoxicity in Rats via Modulating APP/Aβ/P2X7R/P2Y12R and XIAP/BDNF-Dependent Caspase-3 Apoptotic Pathway

Neurotoxicity is an obvious adverse effect in Patients encountering a complete course of chemotherapy. The present work is conducted to evaluate the neuroprotective effect of Ginkgo biloba (Ginkgo) against the neurotoxicity induced by Cisplatin (Cis) in rats. Forty male Wistar albino rats were arranged into four groups: (1) Control group, rats were given saline; (2) Cis group, rats were injected by Cis 2 mg/kg body weight i.p., twice a week starting on the fifth day for thirty days; (3) Ginkgo group, rats were administered Ginkgo (50 mg/kg orally) daily for thirty days; and (4) Ginkgo+Cis group, rats received Ginkgo (50 mg/kg orally) daily and on the fifth day, rats were injected with Cis (2 mg/Kg body weight i.p.) twice a week for thirty days. Cis significantly increased Gamma glutamyltransferase (GGT) and Acetyl Cholinesterase (CHE) as compared to the control group and also disturbed cerebral oxidative/antioxidant redox. Co-administration of Ginkgo and Cis reversed the adverse effect of Cis on the brain tissue. Moreover, co-administration of Ginkgo and Cis ameliorated Cis induced brain damage by reducing Amyloid precursor protein (APP), amyloid β (Aβ), P2Y12R and P2X7R mRNA expressions and proteins. Furthermore, Ginkgo regulated XIAP/BDNF expressions with a consequent decrease of caspase-3 and DNA fragmentation%. The current results concluded that concurrent treatment with Ginkgo can mitigate neurotoxicity mediated by Cis in experimental animals through exhibiting antioxidant effect by restoring cerebral oxidative/antioxidant redox and anti-apoptotic effect via regulating cerebral APP/Aβ/P2Y12R/P2X7R and XIAP/BDNF signaling pathways.

High expression of FUSE binding protein 1 in breast cancer stimulates cell proliferation and diminishes drug sensitivity

Breast cancer is the most common malignant tumor affecting women worldwide and is divided into the following subtypes: Luminal A, Luminal B, HER-2 overexpression and triple-negative breast cancer (TNBC). TNBC accounts for approximately 15-20% of all breast cancer cases. Due to the characteristics of low differentiation, the likelyhood of recurrence and metastasis, strong invasiveness and the lack of hormone receptors and human epidermal growth factor receptor 2 (HER2), patients with TNBC cannot benefit from endocrine therapy or other available targeted agents. Chemotherapy is one of the main treatments for patients with TNBC, and cisplatin is one of the most commonly used and effective drugs. The human far upstream element binding protein 1 (FBP1) is a potent pro-proliferative and anti-apoptotic oncoprotein, which is overexpressed in numerous tumor types. The present study demonstrated that FBP1 and its target, c-Myc, were more highly expressed in breast cancer tissues compared with para-carcinoma tissues, and the FBP1 and c-Myc levels are decreased by cisplatin treatment. The knockdown of FBP1 in TNBC cells decreased cell proliferation by arresting the cell cycle at the G2 phase. The knockdown of FBP1 decreased the expression of G2 phase-associateed protein cyclin A2, whereas it increased that of cyclin B1 and p-CDC2. Furthermore, the knockdown of FBP1 decreased cell migration and metastasis by downregulating matrix metalloproteinase 2 expression, and enhanced the sensitivity of TNBC cells to cisplatin by inducing apoptosis. These results thus suggest that FBP1 is a potential novel biological marker for the diagnosis and treatment of TNBC.

miR-124 Intensified Oxaliplatin-Based Chemotherapy by Targeting CAPN2 in Colorectal Cancer

Our previous study demonstrated that miR-124 was downregulated in colorectal cancer (CRC) compared with normal mucosa, and the downregulated expression of miR-124 was an independent prognostic factor in CRC patients. However, the function of miR-124 in CRC patients treated with chemotherapy is currently unclear. The aim of this study was to determine the miR-124 expression and its regulative role in oxaliplatin (L-OHP)-based chemotherapy of CRC patients. We observed that low miR-124 expression was correlated with worse overall survival (OS) in the 220 patients who received postoperative chemotherapy of 5-fluorouracil [5-FU]+leucovorin+L-OHP (FOLFOX) or capecitabine+L-OHP (XELOX). miR-124 overexpression promoted L-OHP-induced, but not 5-FU-induced, cytotoxicity and apoptosis in HT29 and SW480 cells. CAPN2 was a direct target of miR-124, and its protein expression was reduced by forced expression of miR-124. miR-124 inhibited tumorigenesis and promoted OS of mice bearing xenograft tumors, especially upon L-OHP treatment. miR-124 also promoted L-OHP-induced apoptosis and restrained CAPN2 protein expression in xenograft tumors. Our results suggest that miR-124 could be considered as both a predictor of L-OHP-based chemotherapy for personalized treatment and a therapeutic target for CRC.

A comparative molecular analysis of DNA damage response, cell cycle progression, viability and apoptosis of malignant granulosa cells exposed to gemcitabine and cisplatin

We aimed to provide a comparative characterization of DNA damage response elements, survival/apoptosis and cell cycle progression of the malignant granulosa cells exposed to gemcitabine and cisplatin. Malignant granulosa tumor cell lines COV434 and KGN were used for the experiments. Cell viability, proliferation, DNA damage response and apoptosis were investigated. Cell cycle progression was assessed. In vitro estradiol (E₂) and AMH productions of the cells were measured. Exposure of asynchronous malignant granulosa cells to gemcitabine caused growth arrest, induced DNA damage and activated cellular stress pathways, cell cycle checkpoint sensors and triggered apoptosis as evidenced by increased expression of phospho-p38, γ-histone H2AX, phospho-Chk-1/phospho-Chk-2, and cleaved forms of PARP and caspase-3 in a dose dependent manner. In vitro E₂ and AMH productions of the cells were decreased along with reduction in viable cell mass. Cisplatin treatment produced a similar response but it was associated with JNK activation rather than p38. When the cells were synchronized and treated with gemcitabine at G₂/M transition, the degradation of cyclin B1 and dephosphorylation of cdc-2 at Tyr 15 residue did not occur, resulting in cycle arrest. Similar effects on cell cycle progression was also observed in cisplatin. However, it was associated with JNK activation and higher expression of γ-histone H2AX and cleaved forms of caspase-3 and PARP, indicative of more extensive DNA damage and apoptosis in the cells. This descriptive study provides evidence that gemcitabine exerts cytotoxic effects and causes perturbations in cell cycle progression of malignant granulosa cells.

trans-Platinum(II) Thionate Complexes: Synthesis, Structural Characterization, and in vitro Biological Assessment as Potent Anticancer Agents

A series of Pt(II) complexes trans-[Pt(PPh2 allyl)2 (κ1 -S-SR)2 ], 1, PPh2 allyl=allyldiphenylphosphine, SR=pyridine-2-thiol (Spy, 1 a), 5-(trifluoromethyl)-pyridine-2-thiol (SpyCF3 -5, 1 b), pyrimidine-2-thiol (SpyN, 1 c), benzothiazole-2-thiol (Sbt, 1 d), benzimidazole-2-thiol (Sbi, 1 e), were synthesized. They were characterized by NMR, HR ESI-MS, and X-ray crystallography. Treatment of human cancer cell lines (A549, SKOV3, MCF-7) with these complexes resulted in promising antitumor effects in comparison with cisplatin. These compounds showed suitable selectivity between tumorigenic and non-tumorigenic (MCF-10 A) cell lines. Analyses of cell cycle progression and apoptosis were conducted for 1 a, the most cytotoxic compound, to screen dose/time response and to study the antiproliferative mechanism. An electrophoresis mobility shift assay was performed to assess the direct interaction of 1 a with DNA and the strong genotoxic ability was indicated through the comet assay method.

MiR-483-3p regulates oxaliplatin resistance by targeting FAM171B in human colorectal cancer cells

Oxaliplatin resistance limits the efficiency of treatment for colorectal cancer (CRC). Studies have shown that abnormal expression of microRNAs (miRNAs) were associated with tumorigenesis, cancer development and chemoresistance. The purpose of this study was to identify potential miRNAs related to oxaliplatin resistance in CRC cells. In this work, using small RNA sequencing (small RNA-Seq) and transcriptome sequencing (RNA-Seq), we found that down-regulated miR-483-3p was concurrent with up-regulated FAM171B in oxaliplatin-resistant colorectal cancer cell line HCT116/L as compared with its parental cell line HCT116. Transient transfection of miR-483-3p mimics markedly decreased the levels of FAM171B and restored oxaliplatin responsiveness of HCT116/L cells, and this alteration enhanced cell apoptosis and weakened cell migration. Whereas miR-483-3p inhibitor dramatically promoted the expression of FAM171B and enhanced oxaliplatin resistance of HCT116 cells by repressing cell apoptosis. Furthermore, knockdown of FAM171B in HCT116/L cells could also sensitize its reaction of the treatment with oxaliplatin, which was verified by the reduced cell migration. These findings demonstrate that FAM171B is a functional target of miR-483-3p in the regulation of oxaliplatin resistance in human CRC cells.

Association of MDM2 gene SNP 309 polymorphism and human non-small cell lung cancer susceptibility: A meta-analysis

This updated meta-analysis was performed to evaluate the relationship of a common polymorphism (T309 G, rs2279744 T > G) in the murine double minute 2 (MDM2) gene with susceptibility and prognosis of non-small cell lung cancer (NSCLC). The Cochrane Library, PubMed, Embase, CNKI, WanFang and CNKI databases were searched comprehensively for related study. Odds ratios (ORs) with their 95% confidence intervals (95% CI) were calculated. 11 articles with a total 6470 NSCLC patients and 8027 controls met the inclusion criteria were included. MDM2 T309 G polymorphism might be strongly correlated with an increased risk of NSCLC. The overall pooled analysis indicated that MDM2 309 T/G polymorphism was significantly associated with NSCLC susceptibility in the whole population under allelic (OR: 1.22, 95% CI: 1.08-1.38), recessive (OR: 1.37, 95% CI: 1.15-1.63), dominant (OR: 1.23, 95% CI: 1.04-1.45), and homozygous genetic models (OR: 1.49, 95% CI: 1.20-1.86). The subgroup analysis showed a significant association of MDM2 309 T/G polymorphism with NSCLC susceptibility in Asian population, but not in Caucasian population. Besides, a significant association was found again in the female population. The meta-analysis provides convincing evidence that the MDM2 T309 G polymorphism may contribute to NSCLC susceptibility, especially for Asians and women.

Cannabidiol Overcomes Oxaliplatin Resistance by Enhancing NOS3- and SOD2-Induced Autophagy in Human Colorectal Cancer Cells

Although oxaliplatin is an effective chemotherapeutic drug for colorectal cancer (CRC) treatment, patients often develop resistance to it. Therefore, a new strategy for CRC treatment is needed. The purpose of this study was to determine the effect of cannabidiol (CBD), one of the components of the cannabis plant, in overcoming oxaliplatin resistance in CRC cells. We established oxaliplatin-resistant cell lines, DLD-1 R and colo205 R, in CRC DLD-1 and colo205 cells. Autophagic cell death was induced when oxaliplatin-resistant cells were treated with both oxaliplatin and CBD. Additionally, phosphorylation of nitric oxide synthase 3 (NOS3) was increased in oxaliplatin-resistant cells compared to that in parent cells. Combined treatment with oxaliplatin and CBD reduced phospho-NOS3 levels and nitric oxide (NO) production and resulted in the production of reactive oxygen species (ROS) by reducing the levels of superoxide dismutase 2, an antioxidant present in the mitochondria, causing mitochondrial dysfunction. Taken together, these results suggest that elevated phosphorylation of NOS3 is essential for oxaliplatin resistance. The combination of oxaliplatin and CBD decreased NOS3 phosphorylation, which resulted in autophagy, by inducing the overproduction of ROS through mitochondrial dysfunction, thus overcoming oxaliplatin resistance.

Thymoquinone and geraniol alleviate cisplatin-induced neurotoxicity in rats through downregulating the p38 MAPK/STAT-1 pathway and oxidative stress

AIMS

Cisplatin (CP) is a widely used broad-spectrum antineoplastic agent used to treat a variety of human malignancies. Neurotoxicity is clinically evident in patients who have undergone a full course of chemotherapy. The aim of this study was to investigate the possible protective effects of thymoquinone (TQ) and geraniol (Ger) against CP-induced neurotoxicity in rats.

MAIN METHODS

Forty male Wistar albino rats were allocated into four groups as follows: normal control, CP-induced neurotoxicity, CP + TQ and CP + Ger.

KEY FINDINGS

Our results demonstrated that simultaneous treatment with either TQ or Ger and CP significantly abrogated oxidative stress and downregulated the apoptotic markers p38 mitogen-activated protein kinase (MAPK), STAT-1, p53, p21 and MMP9; FMO3, however, was insignificantly decreased. In addition to the biochemical results, we assessed the histopathological findings, which confirmed the protective effect of TQ and Ger against the brain damage induced by CP.

SIGNIFICANCE

The results of the present study indicate that simultaneous treatment with either TQ or Ger as natural antioxidants can provide protection against cisplatin-induced neurotoxicity in rats by attenuating oxidative stress and cell apoptosis.

Toxicity of C60 fullerene-cisplatin nanocomplex against Lewis lung carcinoma cells

Cisplatin (Cis-Pt) is the cytotoxic agent widely used against tumors of various origin, but its therapeutic efficiency is substantially limited by a non-selective effect and high toxicity. Conjugation of Cis-Pt with nanocarriers is thought to be one option to enable drug targeting. The aim of this study was to estimate toxic effects of the nanocomplex formed by noncovalent interaction of C₆₀ fullerene with Cis-Pt against Lewis lung carcinoma (LLC) cells in comparison with free drug. Scanning tunneling microscopy showed that the minimum size of C₆₀-Cis-Pt nanoparticles in aqueous colloid solution was 1.1 nm whereas that of C₆₀ fullerene was 0.72 nm, thus confirming formation of the nanocomplex. The cytotoxic effect of C₆₀-Cis-Pt nanocomplex against LLC cells was shown to be higher with IC₅₀ values 3.3 and 4.5 times lower at 48 h and 72 h, respectively, as compared to the free drug. 12.5 µM Cis-Pt had no effect on LLC cell viability and morphology while C₆₀-Cis-Pt nanocomplex in Cis-Pt-equivalent concentration substantially decreased the cell viability, impaired their shape and adhesion, inhibited migration and induced accumulation in proapoptotic subG1 phase. Apoptosis induced by the C₆₀-Cis-Pt nanocomplex was confirmed by caspase 3/7 activation and externalization of phosphatidylserine on the outer surface of LLC cells with the double Annexin V-FITC/PI staining. We assume that C₆₀ fullerene as a component of the C₆₀-Cis-Pt nanocomplex promoted Cis-Pt entry and intracellular accumulation thus contributing to intensification of the drug's toxic effect against lung cancer cells.