CircURI1 interacts with hnRNPM to inhibit metastasis by modulating alternative splicing in gastric cancer.

Circular RNAs (circRNAs) have emerged as key regulators of human cancers, yet their modes of action in gastric cancer (GC) remain largely unknown. Here, we identified circURI1 back-spliced from exons 3 and 4 of unconventional prefoldin RPB5 interactor 1 (URI1) from circRNA profiling of five-paired human gastric and the corresponding nontumor adjacent specimens (paraGC). CircURI1 exhibits the significantly higher expression in GC compared with paraGC and inhibitory effects on cell migration and invasion in vitro and GC metastasis in vivo. Mechanistically, circURI1 directly interacts with heterogeneous nuclear ribonucleoprotein M (hnRNPM) to modulate alternative splicing of genes, involved in the process of cell migration, thus suppressing GC metastasis. Collectively, our study expands the current knowledge regarding the molecular mechanism of circRNA-mediated cancer metastasis via modulating alternative splicing.

Hydrophobic Carbon Dots Derived from Organic Pollutants and Applications in NIR Anticounterfeiting and Bioimaging.

In an effort to fulfill the strategy of sustainable development, Rhodamine B, a common and toxic organic pollutant in the textile industry, was reported for the first time as a single precursor to develop a kind of novel hydrophobic nitrogen-doped carbon dot (HNCD) through a green and facile one-pot solvothermal method. The HNCDs with an average size of 3.6 nm possess left and right water contact angles of 109.56° and 110.34°, respectively. The HNCDs manifest excitation wavelength-tunable and upconverted fluorescence from the ultraviolet (UV) to the near-infrared (NIR) range. Furthermore, the PEGylation of HNCDs enables them to be used as an optical marker for cell and in vivo imaging. Notably, the HNCDs with solvent-dependent fluorescence can be used for invisible inks with a wide range of light responses from UV-vis-NIR spectra. This work not only provides an innovative way to recycle chemical waste but also expands the potential application of HNCDs in NIR security printing and bioimaging.

Darinaparsin (ZIO-101) enhances the sensitivity of small-cell lung cancer to PARP inhibitors.

Small-cell lung cancer (SCLC) is an aggressive high-grade neuroendocrine carcinoma of the lung associated with early metastasis and an exceptionally poor prognosis. Little progress has been made in developing efficacious targeted therapy for this recalcitrant disease. Herein, we showed that H3.3, encoded by two genes (H3F3A and H3F3B), was prominently overexpressed in SCLC. Darinaparsin (ZIO-101), a derivative of arsenic trioxide, dose- and time-dependently inhibited the viability of SCLC cells in an H3.3-dependent manner. More importantly, ZIO-101 treatment resulted in substantial accumulation of H3.3 and PARP1 besides induction of G2/M cell cycle arrest and apoptosis in SCLC cells. Through integrative analysis of the RNA-seq data from Cancer Cell Line Encyclopedia dataset, JNCI and Genomics of Drug Sensitivity in Cancer 2 datasets, we found that H3F3A expression was negatively correlated with the IC50 values of PARP inhibitors (PARPi). Furthermore, co-targeting H3.3 and PARP1 by ZIO-101 and BMN673/olaparib achieved synergistic growth inhibition against SCLC in vitro and in vivo. In conclusion, it is feasible to target H3.3 by ZIO-101 to potentiate the response rate of PARPi in SCLC patients.

CircVAPA promotes small cell lung cancer progression by modulating the miR-377-3p and miR-494-3p/IGF1R/AKT axis.

BACKGROUND: Multiple lines of evidence have demonstrated that circular RNAs (circRNAs) play oncogenic or tumor-suppressive roles in various human cancers. Nevertheless, the biological functions of circRNAs in small cell lung cancer (SCLC) are still elusive. METHODS: CircVAPA (annotated as hsa_circ_0006990) was identified by mining the circRNA profiling dataset of six paired SCLC tissues and the RNA-seq data of serum samples from 36 SCLC patients and 118 healthy controls. The circVAPA expression level was evaluated using quantitative real-time PCR in SCLC cells and tissues. Cell viability, colony formation, cell cycle and apoptosis analysis assays and in vivo tumorigenesis were used to reveal the biological roles of circVAPA. The underlying mechanism of circVAPA was investigated by Western blot, RNA pulldown, RNA immunoprecipitation, dual-luciferase reporter assay and rescue experiments. RESULTS: We revealed that circVAPA, derived from exons 2-4 of the vesicle-associated membrane protein-associated protein A (VAPA) gene, exhibited higher expression levels in SCLC cell lines, clinical tissues, and serum from SCLC patients than the controls, and facilitated SCLC progression in vitro and in vivo. Mechanistically, circVAPA activated the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway by modulating the miR-377-3p and miR-494-3p/insulin-like growth factor 1 receptor (IGF1R) axis to accelerate SCLC progression. Furthermore, circVAPA depletion markedly enhanced the inhibitory effects of BMS-536924, an IGF1R kinase inhibitor in cellular and xenograft mouse models. CONCLUSIONS: CircVAPA promotes SCLC progression via the miR-377-3p and miR-494-3p/IGF1R/AKT axis. We hope to develop clinical protocols of combinations of circVAPA inhibition and BMS-536924 addition for treating SCLC with circVAPA upregulation.

Mechanisms of non-coding RNA-modulated alternative splicing in cancer.

Alternative splicing (AS) is a common and pivotal process for eukaryotic gene expression regulation, which enables a precursor RNA to produce multiple transcript variants with diverse cellular functions. Aberrant AS represents a hallmark of cancer, engaged in all stages of tumorigenesis from initiation to metastasis. Accumulating pieces of evidence have revealed the involvement of non-coding RNAs (ncRNAs) in regulating AS in human cancers. In this review, we overview the underlying mechanisms of non-coding RNAs, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) modulated AS at diverse levels in human cancers, and summarize their regulatory functions in tumorigenesis.

FK228 potentiates topotecan activity against small cell lung cancer cells via induction of SLFN11.

The response rate of topotecan, as a second-line chemotherapeutic drug for small cell lung cancer, is ~20%. DNA/RNA helicase SLFN11 (schlafen family member 11), a member of the Schlafen (SLFN) family, is a crucial determinant of response to many DNA damaging agents, expression of SLFN11 tends to augment the antitumor effects of the commonly used DNA-targeting agents. In the present study we investigated how SLFN11 expression regulated the sensitivity of small cell lung cancer to topotecan. We showed that SLFN11 expression levels were positively associated with the sensitivity to topotecan in a panel of seven SCLC cell lines. Topotecan treatment induced different patterns of the DNA response network in SCLC cells: DNA damage response (DDR) was more prominently activated in SLFN11-deficient SCLC cell line H82 than in SLFN11-plentiful SCLC cell line DMS273, whereas topotecan induced significant accumulation of p-Chk1, p-RPA2 and Rad51 in H82 cells, but not in DMS273 cells. We unraveled that SLFN11 expression was highly negatively correlated to the methylation of the SLFN11 promoter. HDAC inhibitors FK228 and SAHA dose-dependently increased SLFN11 expression through suppressing DNA methylation at the SLFN11 promoter, thereby sensitizing SCLC cells to topotecan. Finally, we assessed the methylation status of the SLFN11 promoter in 27 SCLC clinical specimens, and found that most of the clinical samples (24/27) showed DNA methylation at the SLFN11 promoter. In conclusion, it is feasible to combine topotecan with FK228 to improve the response rate of topotecan in SCLC patients.

NIR-II Responsive Hollow Magnetite Nanoclusters for Targeted Magnetic Resonance Imaging-Guided Photothermal/Chemo-Therapy and Chemodynamic Therapy.

Phototherapy in the second near-IR (1000-1700 nm, NIR-II) window has achieved much progress because of its high efficiency and relatively minor side effects. In this paper, a new NIR-II responsive hollow magnetite nanocluster (HMNC) for targeted and imaging-guided cancer therapy is reported. The HMNC not only provides a hollow cavity for drug loading but also serves as a contrast agent for tumor-targeted magnetic resonance imaging. The acid-induced dissolution of the HMNCs can trigger a pH-responsive drug release for chemotherapy and catalyze the hydroxyl radical (·OH) formation from the decomposition of hydrogen peroxide for chemodynamic therapy. Moreover, the HMNCs can adsorb and convert NIR-II light into local heat (photothermal conversion efficacy: 36.3%), which can accelerate drug release and enhance the synergistic effect of chemo-photothermal therapy. The HMNCs show great potential as a versatile nanoplatform for targeted imaging-guided trimodal cancer therapy.

Combinations of proteasome inhibitors with obatoclax are effective for small cell lung cancer.

Proteasome inhibitors, bortezomib (BTZ), and carfilzomib (CFZ) are approved drugs for hematological malignancies, but lack anticancer activities against most solid tumors. Small cell lung cancer (SCLC) is a very aggressive neuroendocrine carcinoma of the lungs demanding effective therapy. In this study we investigated whether BTZ or CFZ combined with obatoclax (OBX), an antagonist for MCL-1 and a pan-BCL family inhibitor, could cause synergistic growth inhibition of SCLC cells. We showed that combined application of BTZ or CFZ with OBX caused synergistic growth inhibition of human SCLC cell lines (H82, H526, DMS79, H196, H1963, and H69) than single agent alone. Both BTZ-OBX and CFZ-OBX combinations displayed marked synergism on inducing apoptosis (~50% increase vs BTZ or CFZ alone). A comprehensive proteomics analysis revealed that BTZ preferentially induced the expression of MCL-1, an antiapoptotic protein, in SCLC cells. Thus, proteasome inhibitor-OBX combinations could specifically induce massive growth inhibition and apoptosis in SCLC cells. Subsequent proteome-wide profiling analysis of activated transcription factors suggested that BTZ- or CFZ-induced MCL-1 upregulation was transcriptionally driven by FOXM1. In nude mice bearing in SCLC H82 xenografts, both BTZ-OBX, and CFZ-OBX combinations exhibited remarkable antitumor activities against SCLC tumors evidenced by significant reduction of tumor size and the proliferation marker Ki-67 signals in tumor tissues as compared with single agent alone. Thus, proteasome inhibitor-OBX combinations are worth immediate assessments for SCLC in clinical settings.

Integrated cistromic and expression analysis of amplified NKX2-1 in lung adenocarcinoma identifies LMO3 as a functional transcriptional target.

The NKX2-1 transcription factor, a regulator of normal lung development, is the most significantly amplified gene in human lung adenocarcinoma. To study the transcriptional impact of NKX2-1 amplification, we generated an expression signature associated with NKX2-1 amplification in human lung adenocarcinoma and analyzed DNA-binding sites of NKX2-1 by genome-wide chromatin immunoprecipitation. Integration of these expression and cistromic analyses identified LMO3, itself encoding a transcription regulator, as a candidate direct transcriptional target of NKX2-1. Further cistromic and overexpression analyses indicated that NKX2-1 can cooperate with the forkhead box transcription factor FOXA1 to regulate LMO3 gene expression. RNAi analysis of NKX2-1-amplified cells compared with nonamplified cells demonstrated that LMO3 mediates cell survival downstream from NKX2-1. Our findings provide new insight into the transcriptional regulatory network of NKX2-1 and suggest that LMO3 is a transcriptional signal transducer in NKX2-1-amplified lung adenocarcinomas.

Germline mutation and aberrant transcripts of WWOX in a syndrome with multiple primary tumors.

Multiple primary tumors are defined by the presence of two or more independent primary tumors in the same or different organs of an individual patient. However, the underlying genetic cause for the development of multiple primary tumors is largely unknown. In the study, we report a rare case with four synchronous distinct histological cancer types in a 26 years old Chinese female. In the patient, whole-exome sequencing identified a homozygous germline insertion mutation in WWOX which encodes the DNA repair-related enzyme, WW domain containing oxidoreductase. The mutation was found in a heterozygous state in her parents and brother without any cancer phenotype thus far. Surprisingly, we found multiple novel aberrant WWOX transcripts in the patient's normal colon tissue. The patient's colon metastasis from clear cell adenocarcinoma of the ovary showed a nonhypermutated profile enriched for C-T transition, and harbored somatic pathogenic mutations of HRAS, BRCA2, SMAD4, CHEK2, and AKT1 genes. To our knowledge, this is the first study reporting WWOX gene aberrations in a young patient with the early occurrence of multiple primary tumors. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

A high-throughput drug screen identifies auranofin as a potential sensitizer of cisplatin in small cell lung cancer.

Small cell lung cancer (SCLC) is a highly lethal malignancy with the 5-year survival rate of less than 7%. Chemotherapy-resistance is a major challenge for SCLC treatment in clinic. In the study, we developed a high-throughput drug screen strategy to identify new drugs that can enhance the sensitivity of chemo-drug cisplatin in SCLC. This screen identified auranofin, a US Food and Drug Administration (FDA)-approved drug used therapeutically for rheumatoid arthritis, as a sensitizer of cisplatin. Further study validated that auranofin synergistically enhanced the anti-tumor activity of cisplatin in chemo-resistant SCLC cells, which was accompanied by the enhanced induction of cell cycle arrest and apoptosis. The synergistic action of auranofin and cisplatin was through ROS overproduction, thereby leading to mitochondrial dysfunction and DNA damage. Furthermore, in vivo study demonstrated that the combination treatment of auranofin and cisplatin dramatically inhibited tumor growth in SCLC. Therefore, our study provides a rational basis for further clinical study to test whether auranofin could enhance the sensitivity of cisplatin-based therapy in SCLC patients.

Loss of the retinoblastoma binding protein 2 (RBP2) histone demethylase suppresses tumorigenesis in mice lacking Rb1 or Men1.

Aberrations in epigenetic processes, such as histone methylation, can cause cancer. Retinoblastoma binding protein 2 (RBP2; also called JARID1A or KDM5A) can demethylate tri- and dimethylated lysine 4 in histone H3, which are epigenetic marks for transcriptionally active chromatin, whereas the multiple endocrine neoplasia type 1 (MEN1) tumor suppressor promotes H3K4 methylation. Previous studies suggested that inhibition of RBP2 contributed to tumor suppression by the retinoblastoma protein (pRB). Here, we show that genetic ablation of Rbp2 decreases tumor formation and prolongs survival in Rb1(+/-) mice and Men1-defective mice. These studies link RBP2 histone demethylase activity to tumorigenesis and nominate RBP2 as a potential target for cancer therapy.

HMGN1 loss sensitizes lung cancer cells to chemotherapy.

The high mobility group nucleosome binding (HMGN) family, constitutes a large family of non-histone protein family known to bind the acidic patch of the nucleosomes with various key cellular functions. Several studies have highlighted the pivotal roles of HMGNs in the pathogenic process of various cancer types. However, the roles of HMGN family in lung adenocarcinoma (LUAD) have not been fully elucidated. Herein, integrative analyses of multiple-omics data revealed that HMGNs frequently exhibit dysregulation in LUAD. Subsequent analysis of the clinical relevance of HMGN1 demonstrated its association with poor prognosis in LUAD and its potential as a diagnostic marker to differentiate LUAD from healthy controls. Additionally, functional enrichment analysis suggested that HMGN1 was mainly involved in DNA repair. To corroborate these findings, cellular experiments were conducted, confirming HMGN1's crucial involvement in homologous recombination repair and its potential to enhance the sensitivity of LUAD cells to standard chemotherapeutic drugs. This study proposes HMGN1 as a novel prognostic biomarker and a promising target for chemotherapy in lung adenocarcinoma.

Enrichment of C17:0-rich saturated fatty acids from sheep tail fat for adjuvant therapy of non-small-cell lung cancer.

Heptadecanoic acid (C17:0), an odd-chain saturated fatty acid (OCSFA) in ruminant lipid, has been demonstrated to be potential for treating cancers. Our results also showed that sheep tail fat (STF) with higher level of C17:0-containing saturated fatty acids (SFAs) whereas lower level of oleic acid (C18:1), performed remarkable inhibition against non-small-cell lung cancer (NSCLC) cells. To enrich the content of C17:0, a C17:0-rich SFA concentrate (HRSC) was prepared from STF by solvent crystallization and urea complexation methods (hexane/STF = 3.5/1, 4 °C for 8 h, and 80% ethanol/urea/free fatty acids = 8/1/1, 4 °C for 6 h). The content of C17:0 was up from 3.02 to 6.34% and the recovery was 4.17%. Biological experiments showed that HRSC exerted better antiproliferative effect against NSCLC cells. Moreover, HRSC performed enhanced inhibitory effect in A549 cell xenograft mouse model. Therefore, HRSC has the potential to be applied in adjuvant therapy for NSCLC. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01504-w.

Metachronous colorectal cancer in Taiwan: analyzing 20 years of data from Taiwan Cancer Registry.

BACKGROUND: The risk of metachronous colorectal cancer in patients with colorectal cancer is higher than the rate of sporadic colorectal cancer in the average population. We conducted a large-scale, population-based study, with many more clinical cases than in previously published studies, to calculate the incidence of metachronous colorectal cancer. METHODS: This is a retrospective study based on data obtained from the Taiwan Cancer Registry from 1988 to 2007. Between 1988 and 2002, we analyzed 70,906 patients who were diagnosed with colon or rectal cancer and traced the occurrence of metachronous lesions with at least 5 years of follow-up. RESULTS: Of these patients, 1,192 (730 males, 462 females; mean age 62.73 ± 12.92 years) developed metachronous cancers. The 15-year cumulative incidence of metachronous cancer was 1.68%. Within 2 years of the index cancer, 51.69% of the metachronous cancers appeared, and 61.27% of the metachronous cancers appeared within 3 years. CONCLUSIONS: Most metachronous lesions were noted within 3 years of initial diagnosis of the index cancer. Surveillance colonoscopy to ensure the absence of metachronous disease is essential for patients after curative surgery within 1 year, especially for those patients who did not receive complete colonoscopy before their first operation for colorectal cancer.

Carbon-Encapsulated Magnetite Nanodoughnut as a NIR-II Responsive Nanozyme for Synergistic Chemodynamic-Photothermal Therapy.

Magnetite-based nanozymes have attracted great interest for catalytic cancer therapy enabled by catalyzing hydrogen peroxide (H2 O2 ) to produce highly toxic hydroxyl radicals (•OH) to kill tumor cells. However, their therapeutic efficacies remain low due to insufficient •OH. Here, a light-responsive carbon-encapsulated magnetite nanodoughnuts (CEMNDs) with dual-catalytic activities for photothermal-enhanced chemodynamic therapy (CDT) is reported. The CEMNDs can accumulate in tumor and get into tumor cells and effectively act as peroxidase to convert H2 O2 to •OH that causes tumor cell death. The CEMNDs also possess intrinsic glutathione oxidase-like activity that which catalyzes the oxidation of reduced glutathione and produce lipid peroxidase for enhanced catalytic therapy. Furthermore, the CEMNDs can absorb 1064 nm light to elevate local temperature and increase release of Fe ions for photothermal therapy and enhanced CDT respectively. The in vivo experiments in an aggressive and drug-resistant metastatic mouse model of triple negative breast cancer model demonstrate excellent synergistic anti-tumor function and no measurable systemic toxicity of CEMNDs.

Corrigendum: The MYC paralog-PARP1 axis as a potential therapeutic target in MYC paralog-activated small cell lung cancer.

[This corrects the article DOI: 10.3389/fonc.2020.565820.].

Gender differences in colorectal cancer during the past 20 years in Taiwan.

PURPOSE: Gender differences in colorectal cancer (CRC) incidence have been previously reported. We designed this population-based study to determine if this gender difference was restricted to specific patient subgroups. METHODS: Using the Taiwan Cancer Registry database, we identified a total of 124,314 CRCs registered from 1988 to 2007. We compared the incidence of CRCs by gender in all CRCs, in colon and rectal cancers considered separately, and in right-sided versus left-sided colon cancers. RESULTS: In individuals aged 50 years and older, the incidence of CRCs was lower in females compared with males. For right-sided colon cancers, the incidence in both genders was similar. Because the proportion of right-sided colon cancer accounted for only one fourth of the total CRCs, its influence on the incidence of total CRCs is reduced. CONCLUSIONS: Although the incidence of total CRCs is male dominant, the actual gender difference in CRC incidence in Taiwan is limited to the left side of the colon.