Heterogeneities in Cell Cycle Checkpoint Activation Following Doxorubicin Treatment Reveal Targetable Vulnerabilities in TP53 Mutated Ultra High-Risk Neuroblastoma Cell Lines.

Most chemotherapeutics target DNA integrity and thereby trigger tumour cell death through activation of DNA damage responses that are tightly coupled to the cell cycle. Disturbances in cell cycle regulation can therefore lead to treatment resistance. Here, a comprehensive analysis of cell cycle checkpoint activation following doxorubicin (doxo) treatment was performed using flow cytometry, immunofluorescence and live-cell imaging in a panel of TP53 mutated ultra high-risk neuroblastoma (NB) cell lines, SK-N-DZ, Kelly, SK-N-AS, SK-N-FI, and BE(2)-C. Following treatment, a dose-dependent accumulation in either S- and/or G2/M-phase was observed. This coincided with a heterogeneous increase of cell cycle checkpoint proteins, i.e., phos-ATM, phos-CHK1, phos-CHK2, Wee1, p21Cip1/Waf1, and p27Kip among the cell lines. Combination treatment with doxo and a small-molecule inhibitor of ATM showed a delay in regrowth in SK-N-DZ, of CHK1 in BE(2)-C, of Wee1 in SK-N-FI and BE(2)-C, and of p21 in Kelly and BE(2)-C. Further investigation revealed, in all tested cell lines, a subset of cells arrested in mitosis, indicating independence on the intra-S- and/or G2/M-checkpoints. Taken together, we mapped distinct cell cycle checkpoints in ultra high-risk NB cell lines and identified checkpoint dependent and independent druggable targets.

Glucocorticoids promote a glioma stem cell-like phenotype and resistance to chemotherapy in human glioblastoma primary cells: Biological and prognostic significance.

Glioma stem cells (GSCs) are glioblastoma (GBM) cells that are resistant to therapy and can give rise to recurrent tumors. The identification of patient-related factors that support GSCs is thus necessary to design effective therapies for GBM patients. Glucocorticoids (GCs) are used to treat GBM-associated edema. However, glucocorticoids participate in the physiological response to psychosocial stress, which has been linked to poor cancer prognosis. This raises concern that glucocorticoids affect the tumor and GSCs. Here, we treated primary human GBM cells with dexamethasone and evaluated GC-driven changes in cell morphology, proliferation, migration, gene expression, secretory activity and growth as neurospheres. Dexamethasone treatment of GBM cells appeared to promote the development of a GSC-like phenotype and conferred resistance to physiological stress and chemotherapy. We also analyzed a potential correlation between GC treatment and tumor recurrence after surgical excision in a population-based consecutive cohort of 48 GBM patients, adjusted for differences in known prognostic factors concerning baseline and treatment characteristics. In this cohort, we found a negative correlation between GC intake and progression-free survival, regardless of the MGMT methylation status. In conclusion, our findings raise concern that treatment of GBM with GCs may compromise the efficacy of chemotherapy and may support a GSC population, which could contribute to tumor recurrence and the poor prognosis of the disease.

Conjugation with polyamines enhances the antibacterial and anticancer activity of chloramphenicol.

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 N(8),N(8)-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.

Direct infection of primary endothelial cells with human cytomegalovirus prevents angiogenesis and migration.

Human cytomegalovirus (hCMV) is a beta herpesvirus that establishes lifelong infection. Although the virus does not usually cause overt clinical symptoms in immunocompetent individuals it can have deleterious effects in immunocompromised patients, such as those on post-transplant medication or with HIV infection. hCMV is the most common congenital infection and can lead to serious fetal sequelae. Endothelial cells (ECs) are natural hosts for hCMV in vivo, therefore, investigations of how this cell type is modulated by infection are key to understanding hCMV pathogenesis. Previous studies have examined the effect of secretomes from hCMV-infected cells on EC angiogenesis, whereas the effect of direct infection on this process has not been so well investigated. Here, we show that placental ECs are viral targets during congenital infection and that vessels in infected tissue appear morphologically abnormal. We demonstrate that the clinical hCMV strain VR1814 impaired EC tube assembly in in vitro angiogenesis assays and inhibited wound healing ability in scratch assays. Secretomes from infected cultures did not impair angiogenesis of uninfected ECs, suggesting that cell-intrinsic changes, as opposed to secreted factors, were responsible. We observed viral gene transcription dependent downregulation of the expression of angiogenesis-associated genes, including angiopoietin-2, TEK receptor and vascular endothelial growth factor receptors. An alternative clinical hCMV stain, TB40E showed similar effects on EC angiogenesis. Together, our data indicate that direct infection with hCMV can induce an anti-migratory and anti-angiogenic EC phenotype, which could have a detrimental effect on the vasculature development in infected tissues.

Synthesis and antimicrobial activity of chloramphenicol-polyamine conjugates.

A series of chloramphenicol (CAM) amides with polyamines (PAs), suitable for structure-activity relationship studies, were synthesized either by direct attachment of the PA chain on the 2-aminopropane-1,3-diol backbone of CAM, previously oxidized selectively at its primary hydroxyl group, or from chloramphenicol base (CLB) through acylation with succinic or phthalic anhydride and finally coupling with a PA. Conjugates 4 and 5, in which the CLB moiety was attached on N4 and N1 positions, respectively, of the N(8),N(8)-dibenzylated spermidine through the succinate linker, were the most potent antibacterial agents. Both conjugates were internalized into Escherichia coli cells by using the spermidine-preferential uptake system and caused decrease in protein and polyamine content of the cells. Noteworthy, conjugate 4 displayed comparable activity to CAM in MRSA or wild-type strains of Staphylococcus aureus and Escherichia coli, but superior activity in E. coli strains possessing ribosomal mutations or expressing the CAM acetyltransferase (cat) gene. Lead compounds, and in particular conjugate 4, have been therefore discovered during the course of the present work with clinical potential.

Investigating the entire course of telithromycin binding to Escherichia coli ribosomes.

Applying kinetics and footprinting analysis, we show that telithromycin, a ketolide antibiotic, binds to Escherichia coli ribosomes in a two-step process. During the first, rapidly equilibrated step, telithromycin binds to a low-affinity site (K(T) = 500 nM), in which the lactone ring is positioned at the upper portion of the peptide exit tunnel, while the alkyl-aryl side chain of the drug inserts a groove formed by nucleotides A789 and U790 of 23S rRNA. During the second step, telithromycin shifts slowly to a high-affinity site (K(T)* = 8.33 nM), in which the lactone ring remains essentially at the same position, while the side chain interacts with the base pair U2609:A752 and the extended loop of protein L22. Consistently, mutations perturbing either the base pair U2609:A752 or the L22-loop hinder shifting of telithromycin to the final position, without affecting the initial step of binding. In contrast, mutation Lys63Glu in protein L4 placed on the opposite side of the tunnel, exerts only a minor effect on telithromycin binding. Polyamines disfavor both sequential steps of binding. Our data correlate well with recent crystallographic data and rationalize the changes in the accessibility of ribosomes to telithromycin in response to ribosomal mutations and ionic changes.

Curcumin Alone and Combined With PI3K Inhibitors Elicits Positive Effects on Oropharyngeal Cancer Cell Lines Regardless of HPV Status.

BACKGROUND/AIM: Human papillomavirus positive (HPV+) oropharyngeal squamous cell carcinoma (OPSCC) is rising in incidence. Compared to HPV-negative (HPV-) OPSCC, HPV+ cases have a better 5-year survival. With its severe side-effects, today's chemoradiotherapy has not improved outcome compared to radiotherapy alone, so new therapies are needed. Mutations in phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), fibroblast growth factor receptor 3 (FGFR3) and cell division cycle 27 (CDC27) are found in HPV+ OPSCC, and in vitro targeted therapy combining PI3K and FGFR inhibitors showed synergistic effects. Here the effects of targeting CDC27 with curcumin with/without various inhibitors or cisplatin on OPSCC cell lines were examined. MATERIALS AND METHODS: Curcumin was administered to HPV+ OPSCC cell lines CU-OP-2, CU-OP-3 and CU-OP-20, and HPV- CU-OP-17 with/without PI3K, cyclin-dependent kinase 4/6, FGFR, poly (ADP-ribose) polymerase or WEE1 inhibitors (BYL719, PD-0332991, JNJ-42756493, BMN-673 and MK-1775, respectively), or cisplatin. The cell lines were then assessed for 72 h after treatment for viability, proliferation and cytotoxicity. RESULTS: Curcumin led to dose-dependent responses with reduced viability and proliferation; upon combining it with BYL719, additional positive effects were found for most OPSCC lines grown as monolayers, and these effects were validated in CU-OP-2 cells grown as spheroids. Curcumin with MK-1775 or PD-0332991 also elicited some positive effects on CU-OP-2 and CU-OP-17 cells. CONCLUSION: Curcumin alone led to dose-dependent responses and when combined with BYL719, positive effects were revealed, as they were when it was combined with MK-1775 or PD-0332991, suggesting a potential use of some of these combinations for HPV+ OPSCC.

Combined targeted therapy with PI3K and CDK4/6, or FGFR inhibitors show synergistic effects in a neuroblastoma spheroid culture model.

AIM: Neuroblastoma (NB) is, in spite of current intensive therapy with severe side effects, still not cured so new therapies are needed. Recently, we showed combining phosphoinositide 3-kinase (PI3K) (BYL719), fibroblast growth factor receptor (FGFR) (JNJ-42756493) and cyclin-dependent kinase 4/6 (CDK4/6) (PD-0332991) inhibitors, in vitro in NB cell lines grown as monolayers had synergistic effects. However, there were variations depending on the combinations used and the targeted NB cell lines. To obtain further information and to mimic more natural circumstances, we investigated the effects of single and combined administrations of the above inhibitors in spheroid NB-cultures. MATERIAL AND METHODS: Spheroid cultures of NB cell lines SK-N-AS, SK-N-BE(2)-C, SK-N-FI and SK-N-SH were established and treated with single and combined administrations of BYL719, JNJ-42756493, and PD-0332991 and followed for growth, viability, proliferation, cytotoxicity and migration. KEY FINDINGS: Single inhibitor administrations gave dose dependent responses with regard to growth and viability and their combinations were efficient and resulted in a range of additive and synergistic effects. The responses to individual drugs and their various combinations were predominantly alike regardless of whether the cells were cultivated in monolayer or D spheroid NB models. However, in general, slightly higher drug concentrations were necessary in spheroidcultures. SIGNIFICANCE: This study provides pre-clinical evidence that single PI3K, FGFR, and CDK4/6, inhibitors exhibit promising anti-NB activity and when combined lower doses of the drugs could be also used in spheroid NB-cultures, supporting the pursuit of further in vitro and in vivo studies in preparation for future potential clinical use.

Human papillomavirus (HPV) load is higher in HPVDNA/p16 positive than in HPVDNA positive/p16 negative oropharyngeal squamous cell carcinoma but does not differ significantly between various subsites or correlate to survival.

OBJECTIVE: Patients with human papillomavirus DNA positive (HPVDNA+) and p16ink4a overexpressing (p16+) oropharyngeal squamous cell carcinoma (OPSCC), especially those with cancer in the tonsillar and base of tongue subsites as compared to other OPSCC subsites have a better outcome than those with only HPVDNA+ or only p16+ cancer. Likewise having a high viral load has been suggested to be a positive prognostic factor. We therefore hypothesized, that HPV viral load could vary depending on OPSCC subsite, as well as with regard to whether the cancer was HPVDNA+ and p16+, or only HPVDNA+, or only p16+ and that this affected outcome. MATERIAL AND METHODS: To address these issues HPV viral load was determined by HPV digital droplet (dd) PCR in tumor biopsies with previously known HPVDNA/p16 status from 270 OPSCC patients diagnosed 2000-2016 in Stockholm, Sweden. More specifically, of these patients 235 had HPVDNA+/p16+, 10 had HPVDNA+/p16-, 13 had HPVDNA-/p16+ and 12 had HPVDNA-/p16- cancer. RESULTS: We found that HPVDNA+/p16+ OPSCC had a significantly higher viral load than HPVDNA+/p16- OPSCC. Moreover, there was a tendency for a higher viral load in the tonsillar and base of tongue OPSCC subsites compared to the other subsites and for a low viral load to correlate to a better clinical outcome but none of these tendencies reached statistical significance. CONCLUSION: To conclude, the mean viral load in HPVDNA+/p16+ OPSCC was higher than in HPVDNA+/p16- OPSCC, but there was no statistically significant difference in viral load depending on OPSCC subsite or on clinical outcome.

New Approaches Towards Targeted Therapy for Childhood Neuroblastoma.

Neuroblastoma (NB), comprising around 10% of all childhood neoplasms and 15% of pediatric cancer deaths is a heterogenous disease and can be divided into very low-, low-, intermediate- and high-risk NB. Treatment of very low/low-risk NB is usually based on observation, or surgery alone, whereas intermediate-risk NB is in addition to surgery treated with mild chemotherapy and roughly 80-95% of the patients are cured. In contrast, high-risk NB patients receive multimodal therapy with e.g. induction, consolidation, and maintenance therapy, which can include induction chemotherapy and surgery and in severe cases adding intensive chemotherapy and even autologous stem cell transplantation and radiotherapy. Unfortunately, however this treatment does not cure all patients and around 50% succumb to disease. For this purpose, new treatment options are urgently needed. In this review, we describe the complex molecular heterogeneity of NB, and potential new options for targeted therapy.

Combination of PARP and WEE1 inhibitors in vitro: Potential for use in the treatment of SHH medulloblastoma.

Medulloblastoma (MB), grouped as either WNT­activated, Sonic hedgehog (SHH)­activated, or non-WNT/non-SHH group 3, accounts for almost 20% of all childhood brain cancers. In spite of current intensive treatments, not all patients are cured and survivors suffer from severe side­effects. The present study therefore examined the effects of the poly­ADP­ribose polymerase (PARP) and WEE1­like protein kinase (WEE1) inhibitors, BMN673 and MK­1775, respectively, alone or in combination on four MB cell lines. More specifically, the MB cell lines, DAOY, UW228­3, MED8A and D425, were tested for their sensitivity to BMN673 and MK­1775 alone or in combination, using cell viability, cell confluency and cytotoxicity assays. The effects on the cell cycle phases were also examined using FACS analysis. Monotherapy with BMN673 and MK­1775 exerted dose­dependent inhibitory effects on the viability of almost all MB cell lines. Notably, when BMN673 and MK­1775 were used in combination, synergistic effects were noted in the SHH group cell lines (DAOY and UW228­3), but not in the already WEE1­sensitive group 3 (MED8A and D425) lines. Moreover, the combination treatment decreased the percentage of cells in the G1 phase and induced the novel distribution of both DAOY and UW228­3 cells in the S and G2/M phases, with the UW228­3 cells exhibiting a greater delay. To conclude, MK­1775 was efficient in all and BMN673 in most cell lines, and their combined use exerted synergistic effects on the SHH, but not the group 3 cell lines. These data suggest that MK­1775 alone may be of interest for all MB cell lines, and that the combination of PARP/WEE1 inhibitors may provide possible therapeutic opportunities for the therapy of SHH MBs. Their use warrants further investigations in the future.

Efficacy of combined targeted therapy with PI3K and CDK4/6 or PARP and WEE1 inhibitors in neuroblastoma cell lines.

Neuroblastoma (NB), the most frequent solid extracranial tumor in children, is not always cured by current aggressive therapies that have notable adverse effects; therefore, novel treatments are necessary. Phosphoinositide 3­kinase (PI3K) and fibroblast growth factor receptor inhibitors exhibit synergistic effect in NB cell lines. In the present study, mono­ and combination therapy of the United States Food and Drug Administration­approved PI3K, cyclin­dependent kinase­4/6 (CDK4/6), poly­ADP­ribose­polymerase (PARP) and WEE1 G2 checkpoint kinase (WEE1) inhibitors (BYL719, PD­0332991, BMN673 and MK­1775, respectively), were used to treat NB cell lines SK­N­AS, SK­N­BE(2)­C, SK­N­DZ, SK­N­FI and SK­N­SH and viability (assessed by WST­1 assay), proliferation (incucyte analysis) and cell cycle (FACS) changes were assessed. Treatments with all single drugs presented dose­-dependent responses with decreased viability and proliferation and combining BYL719 with PD­0332991 or BMN673 with MK­1775 resulted in additive or synergistic effects in most cell lines., except for SK­N­SH for the former and for SK­N­AS for the latter. Moreover, combining MK­1775 and BMN673 decreased the numbers of cells in S phase to a greater extent than either drug alone, while when combining PD­0332991 and BYL719 the observed effect was close to that of PD­0332991 alone. To summarize, PI3K and CDK4/6 or PARP and WEE1 exhibited synergistic anti­NB effects and lower doses of the inhibitors could be utilized, thereby potentially reducing adverse side effects.

High Levels of FGF11 Correlate with Poor Survival in Patients with Human Papillomavirus (HPV)-Positive Oropharyngeal Squamous Cell Carcinoma.

Human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) is associated with a favourable prognosis. It has therefore been suggested that treatment should be individualized and separated by HPV status. However, additional prognostic markers are still needed before treatment can be individualized for this patient group. For this purpose, all patients diagnosed with HPV and p16-positive OPSCC in Stockholm 2000-2009, identified as having a partial/nonresponse to treatment and having viable tumour cells in their neck specimen with material available were categorized as cases. These were matched to controls (complete responders), and the differences in the gene expression were analysed. Two separate verification cohorts were identified including patients with HPV- and p16-positive OPSCC, and the data from the case-control study were verified by qPCR and immunohistochemistry (IHC) in the respective cohorts. A separation of gene expression in correlation with survival was observed in the case-control study, and FGF11 expression was identified as significantly differently expressed between the two groups. The prognostic role of FGF11 was validated in the two cohorts on the RNA and protein levels, respectively. Taken together, our findings suggest that FGF11 may indicate a poor prognosis in HPV-positive OPSCC and may serve as a prognostic biomarker.

Targeted Therapy with PI3K, PARP, and WEE1 Inhibitors and Radiotherapy in HPV Positive and Negative Tonsillar Squamous Cell Carcinoma Cell Lines Reveals Synergy while Effects with APR-246 Are Limited.

Human papillomavirus positive (HPV+) tonsillar and base of tongue cancer (TSCC/BOTSCC) is rising in incidence, but chemoradiotherapy is not curative for all. Therefore, targeted therapy with PI3K (BYL719), PARP (BMN-673), and WEE1 (MK-1775) inhibitors alone or combined was pursued with or without 10 Gy and their effects were analyzed by viability, proliferation, and cytotoxicity assays on the TSCC/BOTSCC cell lines HPV+ UPCI-SCC-154 and HPV- UT-SCC-60A. Effective single drug/10 Gy combinations were validated on additional TSCC lines. Finally, APR-246 was assessed on several TSCC/BOTSCC cell lines. BYL719, BMN-673, and MK-1775 treatments induced dose dependent responses in HPV+ UPCI-SCC-154 and HPV- UT-SCC-60A and when combined with 10 Gy, synergistic effects were disclosed, as was also the case upon validation. Using BYL719/BMN-673, BYL719/MK-1775, or BMN-673/MK-1775 combinations on HPV+ UPCI-SCC-154 and HPV- UT-SCC-60A also induced synergy compared to single drug administrations, but adding 10 Gy to these synergistic drug combinations had no further major effects. Low APR-246 concentrations had limited usefulness. To conclude, synergistic effects were disclosed when complementing single BYL719 BMN-673 and MK-1775 administrations with 10 Gy or when combining the inhibitors, while adding 10 Gy to the latter did not further enhance their already additive/synergistic effects. APR-246 was suboptimal in the present context.

Targeted Therapy of HPV Positive and Negative Tonsillar Squamous Cell Carcinoma Cell Lines Reveals Synergy between CDK4/6, PI3K and Sometimes FGFR Inhibitors, but Rarely between PARP and WEE1 Inhibitors.

Human papillomavirus positive (HPV+) tonsillar and base of tongue squamous cell carcinoma (TSCC/BOTSCC) have a favorable outcome, but upon relapse, survival is poor and new therapeutical options are needed. Recently, we found synergistic effects by combining the food and drug administration approved (FDA) phosphoinositide 3-kinase (PI3K) and fibroblast-growth-factor-receptor (FGFR) inhibitors BYL719 and JNJ-42756493 on TSCC cell lines. Here this approach was extended and Cyclin-Dependent-Kinase-4/6 (CDK4/6) and Poly-ADP-ribose-polymerase (PARP) and WEE1 inhibitors PD-0332991, and MK-1775 respectively were also examined. HPV+ CU-OP-2, -3, -20, and HPV- CU-OP-17 TSCC cell lines were treated with either BYL719 and JNJ-42756493, PD-0332991 BMN-673 and MK-1775 alone or in different combinations. Viability, proliferation, and cytotoxicity were followed by WST-1 assays and the IncuCyte S3 Live® Cell Analysis System. All inhibitors presented dose-dependent inhibitory effects on tested TSCC lines. Synergy was frequently obtained when combining CDK4/6 with PI3K inhibitors, but only sometimes or rarely when combining CDK4/6 with FGFR inhibitors or PARP with WEE1 inhibitors. To conclude, using CDK4/6 with PI3K or FGFR inhibitors, especially PD-0332991 with BYL719 presented synergy and enhanced the decrease of viability considerably, while although dose dependent responses were obtained with PARP and WEE1 inhibitors (BMN-673 and MK-1775 resp.), synergy was rarely disclosed.

New Approaches in Targeted Therapy for Medulloblastoma in Children.

Medulloblastoma (MB) is the most frequent malignant brain tumor in children. Treatment of MB is based on histopathological and molecular stratification, and includes surgical intervention, often with craniospinal irradiation and adjuvant chemotherapy. Unfortunately, however, this treatment leads to a high morbidity rate, and it does not cure all patients either, with around 30% succumbing to their disease. With improved cancer genomics and better molecular characterization, MB has been classified into four major subgroups, wingless-activated, sonic hedgehog-activated, Group 3, and Group 4, with each group consisting of additional subtypes. Recently disclosed genetic drivers of MB may in the future help improve treatment, and in this way reduce therapy-related toxicity. In this review, we describe the heterogeneity of the MB subgroups, and potential new options for targeted therapy.

Targeted Therapy With PI3K and FGFR Inhibitors on Human Papillomavirus Positive and Negative Tonsillar and Base of Tongue Cancer Lines With and Without Corresponding Mutations.

OBJECTIVES: Human 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. METHODS: The 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. RESULTS: HPV+ 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. CONCLUSIONS: The 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.

Prognostic Markers and Driver Genes and Options for Targeted Therapy in Human-Papillomavirus-Positive Tonsillar and Base-of-Tongue Squamous Cell Carcinoma.

The incidence of Human-papillomavirus-positive (HPV+) tonsillar and base-of-tongue squamous cell carcinoma (TSCC and BOTSCC, respectively) is increasing epidemically, but they have better prognosis than equivalent HPV-negative (HPV-) cancers, with roughly 80% vs. 50% 3-year disease-free survival, respectively. The majority of HPV+ TSCC and BOTSCC patients therefore most likely do not require the intensified chemoradiotherapy given today to head and neck cancer patients and would with de-escalated therapy avoid several severe side effects. Moreover, for those with poor prognosis, survival has not improved, so better-tailored alternatives are urgently needed. In line with refined personalized medicine, recent studies have focused on identifying predictive markers and driver cancer genes useful for better stratifying patient treatment as well as for targeted therapy. This review presents some of these endeavors and briefly describes some recent experimental progress and some clinical trials with targeted therapy.

Targeting PI3K, FGFR, CDK4/6 Signaling Pathways Together With Cytostatics and Radiotherapy in Two Medulloblastoma Cell Lines.

OBJECTIVES: Medulloblastoma (MB) is treated with surgery and chemotherapy, with or without irradiation, but unfortunately >20% of the patients are not cured, and treatment comes with serious long-term side effects, so novel treatments are urgently needed. Phosphoinositide 3-kinases (PI3K), fibroblast growth factor receptors (FGFR), and cyclin-D kinases (CDK) play critical roles in cancer, and especially PI3K is crucial in MB, so here targeted therapies against them were explored. METHODS: MB cell lines DAOY and UW228-3 were exposed to PI3K (BYL719), FGFR (JNJ-42756493), and CDK4/6 (PD-0332991) inhibitors, as single or combined treatments, and their viability, cell confluence, apoptosis, and cytotoxicity were examined. Moreover, the inhibitors were combined with cisplatin, vincristine, or irradiation. RESULTS: Single treatments with FGFR, PI3K, or CDK4/6 inhibitors decreased viability and proliferation slightly; however, when combining two inhibitors, or the inhibitors with irradiation, sensitivity was enhanced and lower doses could be used. A more complex pattern was obtained when combining the inhibitors with cisplatin and vincristine. CONCLUSIONS: The data suggest that combination treatments with PI3K, FGFR, and CDK4/6 inhibitors for MB could be beneficial and their use should be pursued further. Likewise, their combination with irradiation gave positive effects, while the addition of cisplatin and vincristine resulted in more complex patterns, which need to be investigated further.

Effects of PI3K and FGFR inhibitors alone and in combination, and with/without cytostatics in childhood neuroblastoma cell lines.

Neuroblastoma (NB) is a heterogenous disease with treatment varying from observation for low­risk tumors, to extensive therapy with chemotherapy, surgery, radiotherapy, and autologous bone­marrow­transplantation and immunotherapy. However, a high frequency of primary­chemo­refractory disease and recurrences urgently require novel treatment strategies. The present study therefore investigated the anti­NB efficacy of the recently FDA­approved phosphoinositide 3­kinase (PI3K) and fibroblast growth factor receptor (FGFR) inhibitors, alpelisib (BYL719) and erdafitinib (JNJ­42756493), alone and in combination with or without cisplatin, vincristine, or doxorubicin on 5 NB cell lines. For this purpose, the NB cell lines, SK­N­AS, SK­N­BE(2)­C, SK­N­DZ, SK­N­FI and SK­N­SH (where SK­N­DZ had a deletion of PIK3C2G and none had FGFR mutations according to the Cancer Program's Dependency Map, although some were chemoresistant), were tested for their sensitivity to FDA­approved inhibitors alone or in combination, or together with cytostatic drugs by viability, cytotoxicity, apoptosis and proliferation assays. The results revealed that monotherapy with alpelisib or erdafitinib resulted in a dose­dependent inhibition of cell viability and proliferation. Notably, the combined use of PI3K and FGFR inhibitors resulted in an enhanced efficacy, while their combined use with the canonical cytotoxic agents, cisplatin, vincristine and doxorubicin, resulted in variable synergistic, additive and antagonistic effects. Collectively, the present study provides pre­clinical evidence that PI3K and FGFR inhibitors exhibit promising anti­NB activity. The data presented herein also indicate that the incorporation of these inhibitors into chemotherapeutic regimens requires careful consideration and further research in order to obtain a beneficial efficacy. Nevertheless, the addition of PI3K and FGFR inhibitors to the treatment arsenal might reduce the occurrence of refractory and relapsing disease in NB without FGFR and PI3K mutations.