PLA2G2D fosters angiogenesis in non-small cell lung cancer through aerobic glycolysis.

Non-small cell lung cancer (NSCLC) stands prominent among the prevailing and formidable oncological entities. The immune and metabolic-related molecule Phospholipase A2, group IID (PLA2G2D) exerts promotional effects on tumor progression. However, its involvement in cancer angiogenesis remains elusive. Therefore, this investigation delved into the functional significance of PLA2G2D concerning angiogenesis in NSCLC. This study analyzed the expression and enriched pathways of PLA2G2D in NSCLC tissues through bioinformatics analysis, and measured the expression of PLA2G2D in NSCLC cells using qRT-PCR and western blot (WB). Subsequently, the viability and angiogenic potential of NSCLC cells were assessed employing CCK-8 and angiogenesis assays, respectively. The expression profile of angiogenic factors was analyzed through WB. Finally, the expression of glycolysis pathway-related genes, extracellular acidification rate and oxygen consumption rate, and the levels of pyruvate, lactate, citrate, and malate were analyzed in NSCLC cells using qRT-PCR, Seahorse XF 96, and related kits. Bioinformatics analysis revealed the upregulation of PLA2G2D in NSCLC tissues and its association with VEGF and glycolysis signaling pathways. Molecular and cellular experiments demonstrated that upregulated PLA2G2D promoted the viability, angiogenic ability, and glycolysis pathway of NSCLC cells. Rescue assays revealed that the effects of high expression of PLA2G2D on the viability, angiogenic ability, and glycolysis of NSCLC cells were weakened after the addition of the glycolysis inhibitor 2-DG. In summary, PLA2G2D plays a key role in NSCLC angiogenesis through aerobic glycolysis, displaying great potential as a target for anti-angiogenesis therapy.

Probing Iron-Mediated Synergistic Change of Cl- and HClO in Liver Cancer Cells with a Dual-Color Fluorescence Reporter.

The ambiguous molecular mechanism remains a leading cause for the high mortality rate of liver cancer. An evident iron overload has been unveiled in liver cancer cell proliferation, which is closely related to oxidative stress. However oxidative stress-regulated chloride intracellular channel protein 1 (CLIC1) obviously increases in liver cancer cells. Cl- is also involved in cell proliferation, and its downstream product, HClO, can induce cell carcinoma when over-generated. However, whether iron overload could mediate the variation of intracellular Cl- and HClO is still uncharted. Herein, we present a dual-responsive fluorescence reporter MQFL-NH2 for simultaneously visualizing the fluctuation of Cl-/HClO at the same spot in living cells. Electrostatic binding to Cl- effectively gave an attenuated signal with blue fluorescence, and HClO induced a sharp green fluorescence. In HL-7702 cells stimulated with iron, the blue/green dual fluorescence of MQFL-NH2 displayed that Cl- and HClO were elevated. In contrast, they were both reduced in iron-removed SMMC-7721 cells. Further results revealed that iron overload could promote the levels of Cl- and HClO by up-regulating CLIC1 and myeloperoxidase. Altogether, the work will energetically contribute to grasp the molecular mechanism in iron overload-mediated pathogenesis of liver cancer.

Rapid Two-Photon Fluorescence Imaging of Monoamine Oxidase B for Diagnosis of Early-Stage Liver Fibrosis in Mice.

Liver fibrosis could induce cirrhosis and liver cancer, causing serious damages to liver function and even death. Early diagnosis of fibrosis is extremely requisite for optimizing treatment schedule to improve cure rate. In early-stage fibrosis, overexpressed monoamine oxidase B (MAO-B) can serve as a biomarker, which greatly contributes to the diagnosis of early liver fibrosis. However, there is still a lack of desired strategy to precisely monitor MAO-B in situ. In this work, we established a two-photon fluorescence imaging method for in vivo detection of MAO-B activity counting on a simply prepared probe, BiPhAA. The BiPhAA could be activated by MAO-B within 10 min and fluoresced brightly. To our knowledge, this BiPhAA-based imaging platform for MAO-B is more rapid than other current detection methods. Furthermore, BiPhAA allowed the dynamic observation of endogenous MAO-B level changes in hepatic stellate cells (LX-2). Through two-photon fluorescence imaging, we observed six times higher fluorescence brightness in the liver tissue of fibrosis mice than that of normal mice, thus successfully distinguishing mice with liver fibrosis from normal mice. Our work offers a simple, fast, and highly sensitive approach for imaging MAO-B in situ and paves a way to the diagnosis of early liver fibrosis with accuracy.

Exploring the Changes of Peroxisomal Polarity in the Liver of Mice with Nonalcoholic Fatty Liver Disease.

Peroxisome proliferator-activated receptor alpha (PPAR-a) is a crucial nuclear transcription regulator of lipid metabolism, which is closely associated with the initiation and development of nonalcoholic fatty liver disease (NAFLD). Because PPAR-a can directly decide the level of peroxisomal metabolic enzymes, its changes might directly cause variations in peroxisomal polarity. Therefore, we developed a new two-photon fluorescence imaging probe, PX-P, in which the triphenylamine and cyanide moieties can real-time sense peroxisomal polarity changes. Using PX-P, we observed a prominent decrease in the peroxisomal polarity in the liver of mice with NAFLD for the first time. More importantly, we discovered that intracellular excessive peroxynitrite (ONOO-) and hydrogen peroxide (H2O2) underwent nitrification and oxidation, respectively, with various sites of PPAR-a. Interestingly, the key site of PPAR-a was nitrated by a low concentration of ONOO- rather than being oxidized by the high level of H2O2. These drastically reduced the activity of PPAR-a, accelerating the occurrence of NAFLD. Moreover, through activating PPARs with pioglitazone, peroxisomal polarity markedly increased compared with that of NAFLD. Altogether, our work presents a new approach for the early diagnosis of NAFLD and identifies potential therapeutic targets.

Halegenticoccus tardaugens sp. nov., an extremely halophilic archaeon isolated from a saline soil.

Two extremely halophilic archaea, isolates SYSU A00711T and SYSU A00630, were isolated from a sediment soil sample collected from the Aiding lake, China. Cells of these isolates were cocci, non-motile and stained Gram-negative. They grew optimally at 37 °C, with 20-22% NaCl (w/v) and at pH 7.5-8.0. Cells lysed in distilled water. Major polar lipids were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, mannosyl glucosyl diether, sulfated mannosyl glucosyl diether, and two unidentified glycolipids. Pairwise sequence comparison revealed that isolates SYSU A00711T and SYSU A00630 were closely related to Halegenticoccus soli SYSU A9-0T (94.1 and 94.0% 16S rRNA gene sequence similarities; 94.0 and 94.2% rpoB' gene similarities, respectively). The overall genomic relatedness indices values between the two isolates and Halegenticocus soli SYSU A9-0 T were: AAI, both 79.6%; ANI, 84.6 and 84.5%; dDDH, 32.5 and 26.3%, respectively. Phylogenetic trees based on the 16S rRNA gene, rpoB' gene, and genome sequences demonstrated a robust clade of these two isolates with Halegenticoccus soli SYSU A9-0T. The DNA G + C contents of these two isolates are both 64.7% (genome method). Based on the differences in phenotypic, chemotaxonomic, and phylogenetic properties, isolates SYSU A00711T and SYSU A00630 are characterized to represent a novel species in the genus Halegenticoccus, for which the name Halegenticoccus tardaugens sp. nov. is proposed. The type strain of the species Halegenticoccus tardaugens is SYSU A00711T (= KCTC 4245T = CGMCC 1.15768T).

Identification of pimavanserin tartrate as a potent Ca2+-calcineurin-NFAT pathway inhibitor for glioblastoma therapy.

Glioblastoma multiforme (GBM) is the most common and malignant type of primary brain tumor, and 95% of patients die within 2 years after diagnosis. In this study, aiming to overcome chemoresistance to the first-line drug temozolomide (TMZ), we carried out research to discover a novel alternative drug targeting the oncogenic NFAT signaling pathway for GBM therapy. To accelerate the drug's clinical application, we took advantage of a drug repurposing strategy to identify novel NFAT signaling pathway inhibitors. After screening a set of 93 FDA-approved drugs with simple structures, we identified pimavanserin tartrate (PIM), an effective 5-HT2A receptor inverse agonist used for the treatment of Parkinson's disease-associated psychiatric symptoms, as having the most potent inhibitory activity against the NFAT signaling pathway. Further study revealed that PIM suppressed STIM1 puncta formation to inhibit store-operated calcium entry (SOCE) and subsequent NFAT activity. In cellula, PIM significantly suppressed the proliferation, migration, division, and motility of U87 glioblastoma cells, induced G1/S phase arrest and promoted apoptosis. In vivo, the growth of subcutaneous and orthotopic glioblastoma xenografts was markedly suppressed by PIM. Unbiased omics studies revealed the novel molecular mechanism of PIM's antitumor activity, which included suppression of the ATR/CDK2/E2F axis, MYC, and AuroraA/B signaling. Interestingly, the genes upregulated by PIM were largely associated with cholesterol homeostasis, which may contribute to PIM's side effects and should be given more attention. Our study identified store-operated calcium channels as novel targets of PIM and was the first to systematically highlight the therapeutic potential of pimavanserin tartrate for glioblastoma.

Visualization of Dynamic Changes in Labile Iron(II) Pools in Endoplasmic Reticulum Stress-Mediated Drug-Induced Liver Injury.

Drug-induced liver injury (DILI) can cause liver failure and even death in severe cases, gravely threatening human health. The treatment of DILI remains a clinical challenge, mainly due to the lack of efficient and accurate diagnosis. Therefore, developing an accurate diagnosis approach is imperative to boost the timely treatment for DILI. As the primary organ of iron storage, liver's functions are tightly linked to iron homeostasis. Thus, monitoring iron homeostasis is promising for the diagnosis and treatment of DILI. Hence, we reported a new near-infrared fluorescent probe (LCy7) that enables real-time and in vivo visualizing of Fe2+ in drug-induced liver injury. In this design, Fe2+ would bind to the N4O ligand in LCy7 and conduce to the C-O bond broken in the presence of O2, which restore the masked QCy7 emitting luminous near-infrared fluorescence. Utilizing LCy7, the increase in Fe2+ was distinctly witnessed in hepatocytes under endoplasmic reticulum stress by acetaminophen (APAP) stimulation. In vivo near-infrared fluorescence imaging revealed the conspicuous rise in Fe2+ in the liver of mice during APAP-induced liver injury. We further unprecedentedly disclosed that endoplasmic reticulum stress was accompanied by the overload of Fe2+ in injured liver of these mice. Collectively, this work will facilitate a greater understanding of the pathogenesis of DILI, and also provide a powerful new tool for DILI diagnosis and treatment.

Abducens nerve schwannoma in cerebellopontine angle mimicking acoustic neuroma.

The abducens nerve schwannoma is one kind of rare intracranial tumor. We report an interesting case of abducens nerve schwannoma in the right cerebellopontine angle in a 68-year-old male patient presenting only vertigo and headache, without any symptom of abducens nerve palsy. This is the oldest patient with abducens nerve schwannoma to date. The patient received a craniectomy via suboccipital retrosigmoid approach and had total surgical excision.

A near-infrared fluorescence probe with large Stokes shift for selectively monitoring nitroreductase in living cells and mouse tumor models.

Hypoxia is commonly regarded as a typical feature of solid tumors, which originates from the insufficient supply of oxygen. Herein, the development of an efficient method for assessing hypoxia levels in tumors is strongly desirable. Nitroreductase (NTR) is an overexpressed reductase in the solid tumors, has been served as a potential biomarker to evaluate the degrees of hypoxia. In this work, we elaborately synthesized a new near-infrared (NIR) fluorescence probe (MR) to monitor NTR activity for assessment of hypoxia levels in living cells and in tumors. Upon exposure of NTR, the nitro-unit of MR could be selectively reduced to amino-moiety with the help of nicotinamide adenine dinucleotide. Moreover, the obtained fluorophore emitted a prominent NIR fluorescence, because it possessed a classical "push-pull" structure. The MR displayed several distinguished characters toward NTR, including intense NIR fluorescent signals, large Stokes shift, high selectivity and low limit of detection (46 ng/mL). Furthermore, cellular confocal fluorescence imaging results validated that the MR had potential of detecting NTR levels in hypoxic cells. Significantly, using the MR, the elevated of NTR levels were successfully visualized in the tumor-bearing mouse models. Therefore, this detecting platform based on this probe may be tactfully constructed for monitoring the variations of NTR and estimating the degrees of hypoxia in tumors.

[Expression and Function of circ_0073585 in Acute Myeloid Leukemia].

OBJECTIVE: To investigate the expression level, clinical significance and function of circular RNAs (circRNAs) circ_0073585 in the bone marrow of patients with acute myeloid leukemia (AML). METHODS: The expression levels of circ_0073585 in bone marrow samples of 106 newly diagnosed AML patients and 38 controls were detected by real-time quantitative PCR (RQ-PCR). The differences were compared between the two groups and their clinical significance was analyzed. The diagnostic value of circ_0073585 expression for AML was evaluated by receiver operating characteristic curve(ROC). THP-1 cells with lentivirus overexpressing circ_0073585 vector and empty vector were divided into two groups: circ_0073585-THP-1 and NC-THP-1 group. CCK-8 assay and flow cytometry were used to study the effects of circ_0073585 on THP-1 cell proliferation, survival, apoptosis and drug sensitivity. RESULTS: Compared with the controls, the expression level of circ_0073585 in the bone marrow of AML patients was significantly reduced (P < 0.001). There was a statistically significant difference between the high and low expression groups of circ_0073585 in the white blood cell count, platelet count (P < 0.01) and chromosome risk (P < 0.05). Compared with NC-THP-1 cells, the proliferation and viability of circ_0073585-THP-1 cells were weakened (P < 0.01), the apoptosis rate was increased (P < 0.01), and the sensitivity to homoharringtonine (P < 0.05) and daunorubicin hydrochloride (P < 0.001) was increased. CONCLUSION: The expression level of circ_0073585 is decreased in AML patients. Overexpression of circ_0073585 can inhibit the proliferation and viability of leukemic cells, promote apoptosis, and increase sensitivity of leukemia cells to chemotherapy drugs.

Crosstalk between circBMI1 and miR-338-5p/ID4 inhibits AML progression.

BMI1 Polycomb Ring Finger Proto-Oncogene (BMI1) is involved in the pathogenesis of different cancers, including acute myeloid leukemia (AML). However, the role of the circular RNA of BMI1 (circBMI1) has not been studied. Our study aimed to investigate the role and mechanism of circBMI1 in AML. circBMI1 was significantly decreased in bone marrow mononuclear cells aspirated from patients with AML. Receiver operating characteristic curve analysis showed that circBMI1 could distinguish patients with AML from controls. By overexpressing and knocking down circBMI1 in HL-60 cells, we found that circBMI1 inhibited cell proliferation, promoted apoptosis, and increased chemotherapeutic drug sensitivity in AML. Experiments using severe combined immune-deficient mice and circBMI1 transgenic mice showed that mice with circBMI1 overexpression had lower white blood cell counts, which suggested less severe AML invasion. RNA immunoprecipitation and dual-luciferase reporter assay revealed binding sites among circBMI1, miR-338-5p, and inhibitor of DNA binding 4 (ID4). Rescue experiments proved that circBMI1 inhibited AML progression by binding to miR-338-5p, which affected the expression of ID4. By coculturing exosomes extracted from circBMI1-HL-60 and small interfering circBMI1-HL-60 cells with HL-60 cells, we found that exosomes from circBMI1-HL-60 cells showed tumor suppressive effects, namely inhibiting HL-60 proliferation, promoting apoptosis, and increasing chemotherapeutic drug sensitivity. Exosomes from small interfering circBMI1-HL-60 cells showed the opposite effects. circBMI1 may act as an exosome-dependent tumor inhibitor. circBMI1, a potential biomarker for clinical diagnosis, acts as a tumor suppressor in AML by regulating miR-338-5p/ID4 and might affect the pathogenesis of AML by exosome secretion.

Near-infrared light-induced photoelectrochemical biosensor based on plasmon-enhanced upconversion nanocomposites for microRNA-155 detection with cascade amplifications.

Herein, a novel near-infrared (NIR) light-driven photoelectrochemical (PEC) biosensor based on NaYF4:Yb3+, Er3+@Bi2MoO6@Bi (NYF@BMO@Bi) nanocomposites was elaborately developed to achieve highly sensitive detection of microRNA-155 (miRNA-155). To realize signal enhancement, the coupled plasmonic bismuth (Bi) nanoparticles were constructed as an energy relay to facilitate the transfer of energy from NaYF4:Yb3+, Er3+ to Bi2MoO6, ultimately enabling the efficient separation of electron-hole pairs of Bi2MoO6 under the irradiation of a 980 nm laser. For constructing biosensing system, the initial signal was firstly amplified after the addition of alkaline phosphatase (ALP) in conjunction with the biofunctionalized NYF@BMO@Bi nanocomposites, which could catalyze the conversion of ascorbic acid 2-phosphate into ascorbic acid, and then consumed the photoacoustic holes created on the surface of Bi2MoO6 for the enlarging photocurrent production. Upon addition of target miRNA-155, the cascade signal amplification process was triggered while the ALP-modified DNA sequence was replaced and then followed by the initiation of a simulated biocatalytic precipitation reaction to attenuate the photocurrent response. On account of the NIR-light-driven and cascade amplifications strategy, the as-constructed biosensor was successfully utilized for the accurate determination of miRNA-155 ranging from 1 fM to 0.1 µM with a detection limit of 0.32 fM. We believed that the proposed nanocomposites-based NIR-triggered PEC biosensor could provide a promising platform for effective monitoring other tumor biomarkers in clinical diagnostics.

Recent Progress in Small-Molecule Fluorescence and Photoacoustic Dual-Modal Probes for the In-Vivo Detection of Bioactive Molecules.

Intracellular bioactive molecules are essential for the maintenance of homeostasis in living organisms. Abnormal levels of them are closely related to the occurrence and development of some diseases. Hence, the direct and accurate visualization of these bioactive molecules is of vital importance for exploring their pathological roles. However, the low-content, short-lived, and widely distributed properties of bioactive molecules impede the comprehensive analysis of them dramatically. Fluorescence and photoacoustic dual-mode imaging technology provides a new solution to the above issue. Specifically, the combination of fluorescence and photoacoustic, which possesses the advantages of high resolution and in-depth tissue analysis, enables a more in-depth and systematic exploration of the pathogenic mechanisms of bioactive molecules. Moreover, due to the structural tailorability of small molecule probes, numerous small molecule dual-mode probes have been developed to meet the demand for real-time tracking and visualization of bioactive molecules in living cells or in vivo. Hence, in this review, we briefly summarize the key advances in small molecule fluorescence and photoacoustic dual-modal probes within recent years (2015-2021). A particular focus is placed on the design strategies and biological applications of probes for the detection of various bioactive molecules in vivo. Furthermore, the challenges and further prospects in this hot field are highlighted.

[Cholesteatoma of the middle ear combined with intracranial and extracranial complications in children: a case report].

In this paper, a case of middle ear cholesteatoma with sigmoid sinus thrombophlebitis and retroauricular subperiosteal abscess was reported. The female patient was hospitalized with bilateral ear abscess for more than 20 days and fever with vomiting for 14 days. Anti-infection treatment after admission, emergency right mastoid radical resection and tympanoplasty were performed under general anesthesia. The patient recovered well after surgery, and there was no recurrence after in the follow-up for more than 2 years.The clinical manifestations, imaging features and prognosis of this disease were discussed and analyzed in the paper.

Demystifying Lysosomal α-l-Fucosidase in Liver Cancer-Bearing Mice by Specific Two-Photon Fluorescence Imaging.

Liver cancer is one of the most frequently diagnosed cancers and has high mortality. However, the early treatment and prognosis can greatly prolong the survival time of patients, which depends on its early detection. α-l-Fucosidase (AFU), as a vital lysosomal hydrolase, is considered to be an ideal biomarker for early stage liver cancer. So, in vivo monitoring of AFU is essential for the early and accurate diagnosis of liver cancer. Hence, we designed the first two-photon turn-on fluorescent reporter, termed HcyCl-F, which localized to lysosomes for fast imaging of AFU. The 2-chloro-4-phenyl-α-l-fucoside bond of HcyCl-F could be effectively hydrolyzed by AFU and released the hydroxyl on the benzene ring, eventually obtaining a strong conjugated compound (HcyCl-OH) with shiny fluorescence. We demonstrated that HcyCl-F was able to rapidly and accurately respond to AFU. Using a two-photon fluorescence microscope, we successfully visualized the fluctuation of AFU in lysosomes. More importantly, a fascinatingly strong fluorescence signal was observed in the tumor tissue of liver cancer-bearing mice. Of note, we confirmed that HcyCl-F could clearly detect liver tumors in stage I. Altogether, our work provides a simple and convenient method for deciphering the critical pathological function of AFU in depth and facilitates the nondestructive and effective diagnosis of liver cancer in the early stage.

Ribosomal protein S6 kinase (RSK)-2 as a central effector molecule in RON receptor tyrosine kinase mediated epithelial to mesenchymal transition induced by macrophage-stimulating protein.

BACKGROUND: Epithelial to mesenchymal transition (EMT) occurs during cancer cell invasion and malignant metastasis. Features of EMT include spindle-like cell morphology, loss of epithelial cellular markers and gain of mesenchymal phenotype. Activation of the RON receptor tyrosine kinase by macrophage-stimulating protein (MSP) has been implicated in cellular EMT program; however, the major signaling determinant(s) responsible for MSP-induced EMT is unknown. RESULTS: The study presented here demonstrates that RSK2, a downstream signaling protein of the Ras-Erk1/2 pathway, is the principal molecule that links MSP-activated RON signaling to complete EMT. Using MDCK cells expressing RON as a model, a spindle-shape based screen was conducted, which identifies RSK2 among various intracellular proteins as a potential signaling molecule responsible for MSP-induced EMT. MSP stimulation dissociated RSK2 with Erk1/2 and promoted RSK2 nuclear translocation. MSP strongly induced RSK2 phosphorylation in a dose-dependent manner. These effects relied on RON and Erk1/2 phosphorylation, which is significantly potentiated by transforming growth factor (TGF)-ß1, an EMT-inducing cytokine. Specific RSK inhibitor SL0101 completely prevented MSP-induced RSK phosphorylation, which results in inhibition of MSP-induced spindle-like morphology and suppression of cell migration associated with EMT. In HT-29 cancer cells that barely express RSK2, forced RSK2 expression results in EMT-like phenotype upon MSP stimulation. Moreover, specific siRNA-mediated silencing of RSK2 but not RSK1 in L3.6pl pancreatic cancer cells significantly inhibited MSP-induced EMT-like phenotype and cell migration. CONCLUSIONS: MSP-induced RSK2 activation is a critical determinant linking RON signaling to cellular EMT program. Inhibition of RSK2 activity may provide a therapeutic opportunity for blocking RON-mediated cancer cell migration and subsequent invasion.

The monoclonal antibody Zt/f2 targeting RON receptor tyrosine kinase as potential therapeutics against tumor growth-mediated by colon cancer cells.

BACKGROUND: Overexpression of the RON receptor tyrosine kinase contributes to epithelial cell transformation, malignant progression, and acquired drug resistance. RON also has been considered as a potential target for therapeutic intervention. This study determines biochemical features and inhibitory activity of a mouse monoclonal antibody (mAb) Zt/f2 in experimental cancer therapy. RESULTS: Zt/f2 is a mouse IgG2a mAb that is highly specific and sensitive to human RON and its oncogenic variants such as RON160 (ED(50) = 2.3 nmol/L). Receptor binding studies revealed that Zt/f2 interacts with an epitope(s) located in a 49 amino acid sequence coded by exon 11 in the RON ß-chain extracellular sequences. This sequence is critical in regulating RON maturation and phosphorylation. Zt/f2 did not compete with ligand macrophage-stimulating protein for binding to RON; however, its engagement effectively induced RON internalization, which diminishes RON expression and impairs downstream signaling activation. These biochemical features provide the cellular basis for the use of Zt/f2 to inhibit tumor growth in animal model. Repeated administration of Zt/f2 as a single agent into Balb/c mice results in partial inhibition of tumor growth caused by transformed NIH-3T3 cells expressing oncogenic RON160. Colon cancer HT-29 cell-mediated tumor growth in athymic nude mice also was attenuated following Zt/f2 treatment. In both cases, ~50% inhibition of tumor growth as measured by tumor volume was achieved. Moreover, Zt/f2 in combination with 5-fluorouracil showed an enhanced inhibition effect of ~80% on HT-29 cell-mediated tumor growth in vivo. CONCLUSIONS: Zt/f2 is a potential therapeutic mAb capable of inhibiting RON-mediated oncogenesis by colon cancer cells in animal models. The inhibitory effect of Zt/f2 in vivo in combination with chemoagent 5-fluorouracil could represent a novel strategy for future colon cancer therapy.

Sustained expression of the RON receptor tyrosine kinase by pancreatic cancer stem cells as a potential targeting moiety for antibody-directed chemotherapeutics.

Cancer stem cells (CSCs) contribute to pancreatic cancer tumorigenesis through tumor initiation, drug resistance, and metastasis. Currently, therapeutics targeting pancreatic CSCs are under intensive investigation. This study tested a novel strategy that utilizes the RON receptor as a drug delivery moiety for increased therapeutic activity against pancreatic CSCs. CD24(+)CD44(+)ESA(+) triple-positive pancreatic CSCs (CSCs(+24/44/ESA)) were obtained from spheroids of pancreatic L3.6pl cancer cells by sequential magnetic cell sorting methods. These cells displayed a spherical growth pattern, expressed the unique self-renewal marker Bmi-1, redifferentiated into an epithelial phenotype, acquired an epithelial to mesenchymal phenotype, and caused tumor formation in animal models. Among several receptor tyrosine kinases examined, RON was highly expressed and sustained by CSCs(+24/44/ESA). This feature provided the cellular basis for validating the therapeutic effectiveness of anti-RON antibody Zt/c9-directing doxorubicin-immunoliposomes (Zt/c9-Dox-IL). Zt/c9-Dox-IL specifically interacted with CSCs(+24/44/ESA) and rapidly caused RON internalization, which led to the uptake of liposome-coated Dox. Moreover, Zt/c9-Dox-IL was effective in reducing viability of L3.6pl cells and CSCs(+24/44/ESA). The IC(50) values between free Dox (62.0 ± 3.1 µM) and Zt/c9-Dox-IL (95.0 ± 6.1 µM) treated CSCs(+24/44/ESA) were at relatively comparable levels. In addition, Zt/c9-Dox-IL in combination with small molecule inhibitors lapatinib, sunitinib, or dasatinib further reduced the viability of CSCs(+24/44/ESA). In conclusion, RON expression by CSCs(+24/44/ESA) is a suitable molecule for the targeted delivery of chemoagents. The anti-RON antibody-directed delivery of chemotherapeutics is effective in reducing viability of pancreatic CSCs.