Association between 19 medication use and risk of common cancers: A cross-sectional and Mendelian randomisation study.

Background: Previous studies have yielded inconsistent results concerning drug use and the risk of cancers. We conducted a large-scale cross-sectional study and a two-sample Mendelian randomisation (MR) study to reveal the causal effect between the use of 19 medications and the risk of four common cancers (breast, lung, colorectal, and prostate). Methods: We obtained information on medication use and cancer diagnosis from National Health and Nutrition Examination Survey participants. After propensity score matching, we conducted survey-weighted multivariate logistic regression and restricted cubic spline analysis to assess the observed correlation between medication use and cancer while adjusting for multiple covariates. We also performed MR analysis to investigate causality based on summary data from genome-wide association studies on medication use and cancers. We performed sensitivity analyses, replication analysis, genetic correlation analysis, and reverse MR analysis to improve the reliability of MR findings. Results: We found that the use of agents acting on the renin-angiotensin system was associated with reduced risk of prostate cancer (odds ratio (OR) = 0.42; 95% confidence interval (CI) = 0.27-0.63, P < 0.001), and there was a nonlinear association of 'decrease-to-increase-to-decrease' (P < 0.0001). The random-effects inverse variance weighted (IVW) model-based primary MR analysis (OR = 0.94, 95% CI = 0.91-0.97, P = 0.0007) and replication MR analysis (OR = 0.90, 95% CI = 0.85-0.96, P = 0.0006) both provided robust evidence of the causality of genetic liability for the use of agents acting on the renin-angiotensin system on a decreased risk of prostate cancer. Conclusions: Our study provides robust evidence that the use of drugs acting on the renin-angiotensin system can reduce prostate cancer risk. Given the high prevalence of prostate cancer, these findings have important implications for drug selection and prostate cancer prevention in patients with cardiovascular disease.

Research on different compound combinations of Realgar-Indigo naturalis formula to reverse acute promyelocytic leukemia arsenic resistance by regulating autophagy through mTOR pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: In China, the Chinese patent drug Realgar-Indigo naturalis Formula (RIF) is utilized for the therapy of acute promyelocytic leukemia (APL). Comprising four traditional Chinese herb-Realgar, Indigo naturalis, Salvia miltiorrhiza, and Pseudostellaria heterophylla-it notably includes tetra-arsenic tetra-sulfide, indirubin, tanshinone IIa, and total saponins of Radix Pseudostellariae as its primary active components. Due to its arsenic content, RIF distinctly contributes to the therapy for APL. However, the challenge of arsenic resistance in APL patients complicates the clinical use of arsenic agents. Interestingly, RIF demonstrates a high remission rate in APL patients, suggesting that its efficacy is not significantly compromised by arsenic resistance. Yet, the current state of research on RIF's ability to reverse arsenic resistance remains unclear. AIM OF THE STUDY: To investigate the mechanism of different combinations of the compound of RIF in reversing arsenic resistance in APL. MATERIALS AND METHODS: The present study utilized the arsenic-resistant HL60-PMLA216V-RARα cell line to investigate the effects of various RIF compounds, namely tetra-arsenic tetra-sulfide (A), indirubin (I), tanshinone IIa (T), and total saponins of Radix Pseudostellariae (S). The assessment of cell viability, observation of cell morphology, and evaluation of cell apoptosis were performed. Furthermore, the mitochondrial membrane potential, changes in the levels of PMLA216V-RARα, apoptosis-related factors, and the PI3K/AKT/mTOR pathway were examined, along with autophagy in all experimental groups. Meanwhile, we observed the changes about autophagy after blocking the PI3K or mTOR pathway. RESULTS: Tanshinone IIa, indirubin and total saponins of Radix Pseudostellariae could enhance the effect of tetra-arsenic tetra-sulfide down-regulating PMLA216V-RARα, and the mechanism was suggested to be related to inhibiting mTOR pathway to activate autophagy. CONCLUSIONS: We illustrated that the synergistic effect of different compound combinations of RIF can regulate autophagy through the mTOR pathway, enhance cell apoptosis, and degrade arsenic-resistant PMLA216V-RARα.

Inhibition of mitochondrial translocase SLC25A5 and histone deacetylation is an effective combination therapy in neuroblastoma.

The mitochondrion is a gatekeeper of apoptotic processes, and mediates drug resistance to several chemotherapy agents used to treat cancer. Neuroblastoma is a common solid cancer in young children with poor clinical outcomes following conventional chemotherapy. We sought druggable mitochondrial protein targets in neuroblastoma cells. Among mitochondria-associated gene targets, we found that high expression of the mitochondrial adenine nucleotide translocase 2 (SLC25A5/ANT2), was a strong predictor of poor neuroblastoma patient prognosis and contributed to a more malignant phenotype in pre-clinical models. Inhibiting this transporter with PENAO reduced cell viability in a panel of neuroblastoma cell lines in a TP53-status-dependant manner. We identified the histone deacetylase inhibitor, suberanilohydroxamic acid (SAHA), as the most effective drug in clinical use against mutant TP53 neuroblastoma cells. SAHA and PENAO synergistically reduced cell viability, and induced apoptosis, in neuroblastoma cells independent of TP53-status. The SAHA and PENAO drug combination significantly delayed tumour progression in pre-clinical neuroblastoma mouse models, suggesting that these clinically advanced inhibitors may be effective in treating the disease.

Extremely Soft, Stretchable, and Self-Adhesive Silicone Conductive Elastomer Composites Enabled by a Molecular Lubricating Effect.

Softness, adhesion, stretchability, and fast recovery from large deformations are essential properties for conductive elastomers that play an important role in the development of high-performance soft electronics. However, it remains an ongoing challenge to obtain conductive elastomers that combine these properties. We have fabricated a super soft (Young's modulus 2.3-12 kPa), highly stretchable (up to 1500% strain), and underwater adhesive silicone conductive elastomer composite (SF-C-PDMS) by incorporating dimethyl silicone oil as a lubricating agent in a cross-linked molecular network. The resultant SF-C-PDMS not only exhibits superior softness but also can readily recover after a strain of 1000%. The initial resistance only decreases by 8% after 100000 cycles of tensile fatigue test (100% strain, 0.5 Hz, 15 mm/s). This multifunctional silicone conductive elastomer composite is obtained in a one-step preparation at room temperature using commercially available materials. Moreover, we illustrate the capabilities of this composite in motion sensing.

MYCN promotes neuroblastoma malignancy by establishing a regulatory circuit with transcription factor AP4.

Amplification of the MYCN oncogene, a member of the MYC family of transcriptional regulators, is one of the most powerful prognostic markers identified for poor outcome in neuroblastoma, the most common extracranial solid cancer in childhood. While MYCN has been established as a key driver of malignancy in neuroblastoma, the underlying molecular mechanisms are poorly understood. Transcription factor activating enhancer binding protein-4 (TFAP4) has been reported to be a direct transcriptional target of MYC. We show for the first time that high expression of TFAP4 in primary neuroblastoma patients is associated with poor clinical outcome. siRNA-mediated suppression of TFAP4 in MYCN-expressing neuroblastoma cells led to inhibition of cell proliferation and migration. Chromatin immunoprecipitation assay demonstrated that TFAP4 expression is positively regulated by MYCN. Microarray analysis identified genes regulated by both MYCN and TFAP4 in neuroblastoma cells, including Phosphoribosyl-pyrophosphate synthetase-2 (PRPS2) and Syndecan-1 (SDC1), which are involved in cancer cell proliferation and metastasis. Overall this study suggests a regulatory circuit in which MYCN by elevating TFAP4 expression, cooperates with it to control a specific set of genes involved in tumor progression. These findings highlight the existence of a MYCN-TFAP4 axis in MYCN-driven neuroblastoma as well as identifying potential therapeutic targets for aggressive forms of this disease.

MYCN amplification confers enhanced folate dependence and methotrexate sensitivity in neuroblastoma.

MYCN amplification occurs in 20% of neuroblastomas and is strongly related to poor clinical outcome. We have identified folate-mediated one-carbon metabolism as highly upregulated in neuroblastoma tumors with MYCN amplification and have validated this finding experimentally by showing that MYCN amplified neuroblastoma cell lines have a higher requirement for folate and are significantly more sensitive to the antifolate methotrexate than cell lines without MYCN amplification. We have demonstrated that methotrexate uptake in neuroblastoma cells is mediated principally by the reduced folate carrier (RFC; SLC19A1), that SLC19A1 and MYCN expression are highly correlated in both patient tumors and cell lines, and that SLC19A1 is a direct transcriptional target of N-Myc. Finally, we assessed the relationship between SLC19A1 expression and patient survival in two independent primary tumor cohorts and found that SLC19A1 expression was associated with increased risk of relapse or death, and that SLC19A1 expression retained prognostic significance independent of age, disease stage and MYCN amplification. This study adds upregulation of folate-mediated one-carbon metabolism to the known consequences of MYCN amplification, and suggests that this pathway might be targeted in poor outcome tumors with MYCN amplification and high SLC19A1 expression.

ABCC multidrug transporters in childhood neuroblastoma: clinical and biological effects independent of cytotoxic drug efflux.

BACKGROUND: Although the prognostic value of the ATP-binding cassette, subfamily C (ABCC) transporters in childhood neuroblastoma is usually attributed to their role in cytotoxic drug efflux, certain observations have suggested that these multidrug transporters might contribute to the malignant phenotype independent of cytotoxic drug efflux. METHODS: A v-myc myelocytomatosis viral related oncogene, neuroblastoma derived (MYCN)-driven transgenic mouse neuroblastoma model was crossed with an Abcc1-deficient mouse strain (658 hMYCN(1/-), 205 hMYCN(+/1) mice) or, alternatively, treated with the ABCC1 inhibitor, Reversan (n = 20). ABCC genes were suppressed using short interfering RNA or overexpressed by stable transfection in neuroblastoma cell lines BE(2)-C, SH-EP, and SH-SY5Y, which were then assessed for wound closure ability, clonogenic capacity, morphological differentiation, and cell growth. Real-time quantitative polymerase chain reaction was used to examine the clinical significance of ABCC family gene expression in a large prospectively accrued cohort of patients (n = 209) with primary neuroblastomas. Kaplan-Meier survival analysis and Cox regression were used to test for associations with event-free and overall survival. Except where noted, all statistical tests were two-sided. RESULTS: Inhibition of ABCC1 statistically significantly inhibited neuroblastoma development in hMYCN transgenic mice (mean age for palpable tumor: treated mice, 47.2 days; control mice, 41.9 days; hazard ratio [HR] = 9.3, 95% confidence interval [CI] = 2.65 to 32; P < .001). Suppression of ABCC1 in vitro inhibited wound closure (P < .001) and clonogenicity (P = .006); suppression of ABCC4 enhanced morphological differentiation (P < .001) and inhibited cell growth (P < .001). Analysis of 209 neuroblastoma patient tumors revealed that, in contrast with ABCC1 and ABCC4, low rather than high ABCC3 expression was associated with reduced event-free survival (HR of recurrence or death = 2.4, 95% CI = 1.4 to 4.2; P = .001), with 23 of 53 patients with low ABCC3 expression experiencing recurrence or death compared with 31 of 155 patients with high ABCC3. Moreover, overexpression of ABCC3 in vitro inhibited neuroblastoma cell migration (P < .001) and clonogenicity (P = .03). The combined expression of ABCC1, ABCC3, and ABCC4 was associated with patients having an adverse event, such that of the 12 patients with the "poor prognosis" expression pattern, 10 experienced recurrence or death (HR of recurrence or death = 12.3, 95% CI = 6 to 27; P < .001). CONCLUSION: ABCC transporters can affect neuroblastoma biology independently of their role in chemotherapeutic drug efflux, enhancing their potential as targets for therapeutic intervention.

Direct and coordinate regulation of ATP-binding cassette transporter genes by Myc factors generates specific transcription signatures that significantly affect the chemoresistance phenotype of cancer cells.

Increased expression of specific ATP-binding cassette (ABC) transporters is known to mediate the efflux of chemotherapeutic agents from cancer cells. Therefore, establishing how ABC transporter genes are controlled at their transcription level may help provide insight into the role of these multifaceted transporters in the malignant phenotype. We have investigated ABC transporter gene expression in a large neuroblastoma data set of 251 tumor samples. Clustering analysis demonstrated a strong association between differential ABC gene expression patterns in tumor samples and amplification of the MYCN oncogene, suggesting a correlation with MYCN function. Using expression profiling and chromatin immunoprecipitation studies, we show that MYCN oncoprotein coordinately regulates transcription of specific ABC transporter genes, by acting as either an activator or a repressor. Finally, we extend these notions to c-MYC showing that it can also regulate the same set of ABC transporter genes in other tumor cells through similar dynamics. Overall our findings provide insight into MYC-driven molecular mechanisms that contribute to coordinate transcriptional regulation of a large set of ABC transporter genes, thus affecting global drug efflux.

Small-molecule multidrug resistance-associated protein 1 inhibitor reversan increases the therapeutic index of chemotherapy in mouse models of neuroblastoma.

The multidrug resistance-associated protein 1 (MRP1) has been closely linked to poor treatment response in several cancers, most notably neuroblastoma. Homozygous deletion of the MRP1 gene in primary murine neuroblastoma tumors resulted in increased sensitivity to MRP1 substrate drugs (vincristine, etoposide, and doxorubicin) compared with tumors containing both copies of wild-type MRP1, indicating that MRP1 plays a significant role in the drug resistance in this tumor type and defining this multidrug transporter as a target for pharmacologic suppression. A cell-based readout system was created to functionally determine intracellular accumulation of MRP1 substrates using a p53-responsive reporter as an indicator of drug-induced DNA damage. Screening of small-molecule libraries in this readout system revealed pyrazolopyrimidines as a prominent structural class of potent MRP1 inhibitors. Reversan, the lead compound of this class, increased the efficacy of both vincristine and etoposide in murine models of neuroblastoma (syngeneic and human xenografts). As opposed to the majority of inhibitors of multidrug transporters, Reversan was not toxic by itself nor did it increase the toxicity of chemotherapeutic drug exposure in mice. Therefore, Reversan represents a new class of nontoxic MRP1 inhibitor, which may be clinically useful for the treatment of neuroblastoma and other MRP1-overexpressing drug-refractory tumors by increasing their sensitivity to conventional chemotherapy.

p53 determines multidrug sensitivity of childhood neuroblastoma.

For pediatric cancers like neuroblastoma, the most common extracranial solid tumor of infancy, p53 mutations are rare at diagnosis, but may be acquired after chemotherapy, suggesting a potential role in drug resistance. Heavy metal-selected neuroblastoma cells were found to acquire an unusually broad multidrug resistance (MDR) phenotype but displayed no alterations in genes associated with "classic" MDR. These cells had acquired a mutant p53 gene, linking p53 to drug sensitivity in neuroblastoma. We therefore generated p53-deficient variants in neuroblastoma cell lines with wild-type p53 by transduction of p53-suppressive constructs encoding either short hairpin RNA or a dominant-negative p53 mutant. Analysis of these cells indicated that (a) in contrast to previous reports, wild-type p53 was fully functional in all neuroblastoma lines tested; (b) inactivation of p53 in neuroblastoma cells resulted in establishment of a MDR phenotype; (c) p53-dependent senescence, the primary response of some neuroblastoma cells to DNA damage, is replaced after p53 inactivation by mitotic catastrophe and subsequent apoptosis; (d) knockdown of mutant p53 did not revert the MDR phenotype, suggesting it is determined by p53 inactivation rather than gain of mutant function. These results suggest the importance of p53 status as a prognostic marker of treatment response in neuroblastoma. p53 suppression may have opposite effects on drug sensitivity as determined by analysis of isogenic pairs of tumor cell lines of nonneuroblastoma origin, indicating the importance of tissue context for p53-mediated modulation of tumor cell sensitivity to treatment.

The p53 pathway and its inactivation in neuroblastoma.

Early studies of p53 in neuroblastoma reported infrequent mutations in tumours and cell lines. Cytoplasmic sequestration was later proposed as an alternative mechanism of inactivation, but many studies have since reported an intact p53 pathway in neuroblastoma cell lines, as detected by nuclear p53 accumulation after DNA damage, intact DNA binding, transcriptional activation of target genes and the induction of apoptosis. In some MYCN amplified cell lines however, an irradiation induced G(1) arrest does not occur, despite the presence of normal p53. Neuroblastoma usually responds to chemotherapy but frequently relapses, and there is evidence from tumours, and cell lines that p53 inactivation via mutation or MDM2 amplification occurs at relapse and is sometimes associated with multidrug resistance. If p53 inactivation occurs frequently in relapsed tumours it may be appropriate to include p53 independent therapies in the initial management of high-risk neuroblastoma.

Importance of minimal residual disease testing during the second year of therapy for children with acute lymphoblastic leukemia.

PURPOSE: A high level of minimal residual disease (MRD) after induction chemotherapy in children with acute lymphoblastic leukemia (ALL) is an indicator of relative chemotherapy resistance and a risk factor for relapse. However, the significance of MRD in the second year of therapy is unclear. Moreover, it is unknown whether treatment intervention can alter outcome in patients with detectable MRD. PATIENTS AND METHODS: We assessed the prognostic value of MRD testing in bone marrow samples from 85 children at 1, 12, and 24 months from diagnosis using clone-specific polymerase chain reaction primers designed to detect clonal antigen receptor gene rearrangements. These children were part of a multicenter, randomized clinical trial, which, in the second year of treatment, compared a 2-month reinduction-reintensification followed by maintenance chemotherapy with standard maintenance chemotherapy alone. RESULTS: MRD was detected in 69% of patients at 1 month, 25% at 12 months, and 28% at 24 months from diagnosis. By univariate analysis, high levels of MRD at 1 month, or the presence of any detectable MRD at 12 or 24 months from diagnosis, were highly predictive of relapse. Multivariate analysis showed that MRD testing at 1 and 24 months each had independent prognostic significance. Intensified therapy at 12 months from diagnosis did not improve prognosis in those patients who were MRD positive at 12 months from diagnosis. CONCLUSION: Clinical outcome in childhood ALL can be predicted with high accuracy by combining the results of MRD testing at 1 and 24 months from diagnosis.

The nonobese diabetic/severe combined immunodeficient (NOD/SCID) mouse model of childhood acute lymphoblastic leukemia reveals intrinsic differences in biologic characteristics at diagnosis and relapse.

Acute lymphoblastic leukemia cells from 19 children, including 7 who remain in first complete remission (CR1), were engrafted into nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice. High-level infiltration of bone marrow, spleen, and liver was observed, with variable infiltration of other organs. The immunophenotypes of xenografts were essentially unaltered compared with the original patient sample. In addition, sequencing of the entire p53 coding region revealed no mutations in 14 of 14 xenografts (10 from patients at diagnosis and 4 at relapse). Cells harvested from the spleens of engrafted mice readily transferred the leukemia to secondary and tertiary recipients. To correlate biologic characteristics of xenografts with clinical and prognostic features of the patients, the rates at which individual leukemia samples engrafted in NOD/SCID mice were analyzed. Differences in biologic correlates were encountered depending on stage of disease: a direct correlation was observed between the rate of engraftment and length of CR1 for samples harvested at relapse (r = 0.96; P =.002), but not diagnosis (r = 0.38; P =.40). In contrast, the in vivo responses of 6 xenografts to vincristine showed a direct correlation (r = 0.96; P =.002) between the length of CR1 and the rate at which the leukemia cell population recovered following vincristine treatment, regardless of whether the xenografts were derived from patients at diagnosis or relapse. This study supports previous findings that the NOD/SCID model of childhood ALL provides an accurate representation of the human disease and indicates that it may be of value to predict relapse and design alternative treatment strategies in a patient-specific manner.