Chloramphenicol (CAM) is a broad-spectrum antibiotic, limited to occasional only use in developed countries because of its potential toxicity. To explore the influence of polyamines on the uptake and activity of CAM into cells, a series of polyamine–CAM conjugates were synthesized. Both polyamine architecture and the position of CAM-scaffold substitution were crucial in augmenting the antibacterial and anticancer potency of the synthesized conjugates. Compounds 4 and 5, prepared by replacement of dichloro-acetyl group of CAM with succinic acid attached to N4 and N1 positions of N8,N8-dibenzylspermidine, respectively, exhibited higher activity than CAM in inhibiting the puromycin reaction in a bacterial cell-free system. Kinetic and footprinting analysis revealed that whereas the CAM-scaffold preserved its role in competing with the binding of aminoacyl-tRNA 3′-terminus to ribosomal A-site, the polyamine-tail could interfere with the rotatory motion of aminoacyl-tRNA 3′-terminus toward the P-site. Compared to CAM, compounds 4 and 5 exhibited comparable or improved antibacterial activity, particularly against CAM-resistant strains. Compound 4 also possessed enhanced toxicity against human cancer cells, and lower toxicity against healthy human cells. Thus, the designed conjugates proved to be suitable tools in investigating the ribosomal catalytic center plasticity and some of them exhibited greater efficacy than CAM itself.
Background/Aim: Medulloblastoma (MB) accounts for ~20% of pediatric malignant central nervous system tumors. Treatment strategies, including surgery, radiation therapy and/or chemotherapy, are effective, but recurrence and metastasis frequently occur. Therefore, novel therapies are required. Herein, the effects of fibroblast growth factor receptor (FGFR) and phosphoinositide 3kinase (PI3K) inhibitors on MB cells lines were evaluated. Materials and Methods: ΜΒ cell lines (UW228-3, DAOY, Med8a, D425, D283) were tested for sensitivity to FGFR (AZD4547) and PI3K (BEZ235 and BYL719) inhibitors by viability, cytotoxicity, apoptosis, and proliferation assays. Results: Single treatments with FGFR and PI3K inhibitors decreased viability and proliferation in a dose-dependent pattern in most cell lines. Combinination of the two type of drugs, increased sensitivity, especially of the most resistant cell line UW228-3. Conclusion: Combination treatments with FGFR and PI3K inhibitors were superior to single treatments with FGFR and PI3K inhibitors, especially with BEZ235, for MB cell lines.Cancer is a leading cause of death for children and adolescents around the world and approximately 300,000 children aged 0 to 19 years old are diagnosed with cancer each year (1). Although leukaemia is the most common cancer in childhood (30% of paediatric malignancies), brain and central nervous system (CNS) tumors are the most frequent among the solid tumors (20% of childhood cancers) (2). Medulloblastomas (MBs), which are the main focus of the current study, are among the most common malignant brain tumors, accounting for 16-25% of all CNS tumors in children, and usually arise in the cerebellum (3-6). According to recent advances in genomics, gene expression profiling, and epigenomics, MBs are divided into at least four subgroups: Wingles/Integrated (WNT), Sonic Hedgehog (SHH), Group 3 and Group 4 (7-9). The largest subgroups are: Group 4 and SHH-activated MB, which account for 35% and 30% of tumors respectively, and they both have intermediate prognosis. Group 3 tumors are found in 25% cases and have the worst prognosis, while WNT comprises 10% of MB tumors and has the best prognosis (7,10,11).The current treatment of MBs consists of removal of the tumor by surgery, radiation therapy (X-rays or protons) and chemotherapy (12). Despite this multipronged approach to therapy, approximately 30% of patients still die from the disease, and survivors suffer from severe long-term side effects, including neurological deficits, endocrine disorders, and secondary cancers (13). Therefore, novel combination therapies, ideally with fewer side effects, are needed. In this context, the present study focuses on the fibroblast growth factor receptor (FGFR) and its downstream phosphatidylinositol 3-kinase (PI3K) pathways, which both could be potential targets for future treatment strategies for MB.FGFRs are a family of receptor tyrosine kinases expressed on the cell membrane, and are crucial during development, as well as in adult cells. Their dysregulation ...
Fibroblast growth factor receptor (FGFR)3 and phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) mutations are found in various types of cancer, such as urinary bladder cancer, human papillomavirus-positive tonsillar and base of the tongue squamous cell carcinoma, breast cancer and some childhood sarcomas. Several drugs can target these genes, some of which have been used for the treatment of urinary bladder cancer. Much less is known about childhood cancer. For this reason, the present study investigated the presence of such mutations in neuroblastomas (NBs) and tested NB cell lines for sensitivity to FGFR and phosphoinositide 3-kinase (PI3K) inhibitors. In total, 29 NBs were examined for the presence of the three most common FGFR3 and PIK3CA mutations using a competitive allele-specific TaqMan PCR (CAST-PCR). Furthermore, the SK-N-AS, SK-N-BE(2)-C, SK-N-DZ, SK-N-FI and SK-N-SH NB cell lines (where SK-N-DZ had a deletion of PIK3C2G, none had FGFR mutations according to the Cancer Program's Dependency Map, but some were chemoresistant), were tested for sensitivity to FGFR (AZD4547) and PI3K (BEZ235 and BKM120) inhibitors by viability, cytotoxicity, apoptosis and proliferation assays. CAST-PCR detected one FGFR3 mutation in 1/29 NBs. Following treatment with FGFR and PI3K inhibitors, a decrease in viability and proliferation was observed in the majority, but not all, the cell lines. Following combination treatment with both drugs, the sensitivity of all cell lines was increased. On the whole, the findings of this study demonstrate that FGFR3 and PIK3CA mutations are uncommon in patients with NB. However, certain NB cell lines are rather sensitive to both FGFR and PI3K inhibitors alone, and even more so when the different drugs are used in combination.
Human cytomegalovirus (HCMV) has been detected in various types of tumors. We studied the prevalence of HCMV in ovarian cancer and its relation to clinical outcome. Paraffin-embedded tissues obtained prospectively from 45 patients with ovarian cancer and 30 patients with benign ovarian cystadenoma were analyzed for expression of HCMV immediate-early protein (IE) and HCMV tegument protein (pp65) by immunohistochemistry. Plasma was analyzed for HCMV serology. HCMV-IgG levels were higher in patients with ovarian cancer or benign cystadenoma than in age-matched controls (P = .002, P < .0001, respectively). HCMV IgM was detected in 12% of ovarian cancer patients and 3% of patients with benign tumors but was absent in controls. In patients with ovarian cancer, higher IgG levels were associated with better outcomes (P = .04). Extensive HCMV-IE protein expression was detected in 75% of ovarian cancers and 26% of benign tumors; pp65 was detected in 67% of ovarian cancers and 14% of benign tumors. A higher grade of HCMV infection was associated with higher stage of disease. Extensive HCMV-pp65 expression was associated with shorter median overall survival than focal expression (39 versus 42.5 months, P = .03). At study closure, 58% of ovarian cancer patients with focal pp65 expression were alive versus 27% of patients with extensive pp65 expression (P = .03). Thus, HCMV proteins are detected at different levels in ovarian tumors and benign cystadenomas. Ovarian cancer patients with focal HCMV-pp65 expression in their tumors and high IgG levels against HCMV lived longer, highlighting a need for in-depth studies of the oncomodulatory role of HCMV in ovarian cancer.
ObjectivesHuman papillomavirus positive (HPV+) tonsillar and base of tongue squamous cell carcinoma (TSCC/BOTSCC), the major subsites of oropharyngeal squamous cell carcinoma (OPSCC) have favorable outcome, but upon relapse, outcome is poor and new therapies needed. Since, phosphatidyl-inositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) and fibroblast-growth-factor-receptor-3 (FGFR3) mutations often occur in such tumors, here, we tested targeted therapy directed to such genes in TSCC/BOTSCC cell lines. We also combined the two types of inhibitors with each other, and cisplatin or docetaxel that are used clinically.MethodsThe HPV+ CU-OP-2, -3, -20, UPCI-SCC-154, and HPV- CU-OP-17 and UT-SCC-60A cell lines were first tested for common PIK3CA/FGFR3 mutations by competitive-allele-specific TaqMan-PCR. They were then treated with the food and drug administration (FDA) approved drugs, alpelisib (BYL719) and erdafitinib (JNJ-42756493) alone and in combination with cisplatin or docetaxel. Viability, proliferation, apoptosis and cytotoxicity responses were thereafter followed by WST-1 assays and the IncuCyte S3 Live® Cell Analysis System.ResultsHPV+ CU-OP-2 had a pS249C-FGFR3, and like CU-OP-20, a pE545K-PIK3CA mutation, while no other lines had such mutations. Irrespectively, dose dependent responses to all PI3K/FGFR inhibitors were obtained, and upon combining the inhibitors, positive effects were observed. Cisplatin and docetaxel also induced dose dependent responses, and upon combination with the inhibitors, both positive and neutral effects were found.ConclusionsThe data suggest that FDA approved drugs alpelisib and erdafitinib efficiently inhibit TSCC/BOTSCC cell line growth, especially when combined irrespective of presence of corresponding mutations and should be further explored, for use upon recurrent disease.
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