Cargo-eliminated osteosarcoma-derived small extracellular vesicles mediating competitive cellular uptake for inhibiting pulmonary metastasis of osteosarcoma.

Osteosarcoma (OS) derived small extracellular vesicles (OS-sEVs) have been shown to induce the formation of cancer-associated fibroblasts (CAFs), characterized by elevated pro-inflammatory factor expression and enhanced migratory and contractile abilities. These CAFs play a crucial role in priming lung metastasis by orchestrating the pre-metastatic niche (PMN) in the lung. Disrupting the communication between OS-sEVs and lung fibroblasts (LFs) emerges as a potent strategy to hinder OS pulmonary metastasis. Our previously established saponin-mediated cargo-elimination strategy effectively reduces the cancer-promoting ability of tumor-derived small extracellular vesicles (TsEVs) while preserving their inherent targeting capability. In this study, we observed that cargo-eliminated OS-sEVs (CE-sEVs) display minimal pro-tumoral and LFs activation potential, yet retain their ability to target LFs. The uptake of OS-sEVs by LFs can be concentration-dependently suppressed by CE-sEVs, preventing the conversion of LFs into CAFs and thus inhibiting PMN formation and pulmonary metastasis of OS. In summary, this study proposes a potential strategy to prevent LFs activation, PMN formation in the lung, and OS pulmonary metastasis through competitive inhibition of OS-sEVs' function by CE-sEVs.

Sensitive electrochemical biosensor for rapid detection of sEV-miRNA based turbo-like localized catalytic hairpin assembly.

Small extracellular vesicle-associated microRNAs (sEV-miRNAs) have emerged as critical biomarkers for cancer diagnosis, yet the rapid detection of these low-abundance molecules in clinical samples remains a formidable challenge. Herein, a simple turbo-like localized catalytic hairpin assembly (TL-CHA) was proposed for sEV-miR-1246 measurement. This electrochemical sensor achieves dual localization through the ingeniously use of AuNPs and DNA nanowires, which provides rich sites for CHA cascade amplification, significantly enhancing the effective reaction and amplify the detection response. Leveraging this innovative design, this biosensor demonstrated the ability to detect sEV-miRNA at concentrations as low as 5.24 aM in a time frame of 30 min. The precision of the measurements was validated through reverse transcription quantitative polymerase chain reaction. Furthermore, the sensor was used for analyzing plasma samples from gastric cancer patients yielded AUC values of 0.973 for all stages and 0.945 for early stages. This demonstrates the sensor's robust performance in both the staging diagnosis and early screening of gastric cancer. Therefore, this platform has great potential for the clinical cancer diagnosis.

Endosome associated trafficking regulator 1 promotes tumor growth and invasion of glioblastoma multiforme via inhibiting TNF signaling pathway.

PURPOSE: Endosome associated trafficking regulator 1 (ENTR1) is a novel endosomal protein, which can affect multiple cellular biological behavior by remodeling plasma membrane structures. However, little is known regarding its function and underlying mechanisms in glioblastoma multiforme. METHODS: Expression profile and clinical signature were obtained from The Public Database of human tumor. Immunohistochemical staining and western blotting assays were used to measure ENTR1 expression level. Human primary GBM tumor cells and human GBM cell lines A172, U87 and U251 were used to clarify the precise role of ENTR1. CCK-8 assays, wound healing and transwell invasion assays were designed to investigate cell viability, invasion and migration of GBM cells, respectively. Underlying molecular mechanisms of ENTR1 were determined via RNA-seq analysis. Tumor formation assay was used to validate the influence of ENTR1 in vivo. RESULTS: Compared with normal brain tissues, ENTR1 was highly expressed in gliomas and correlated with malignant grades of gliomas and poor overall survival time. The proliferation and invasion of GBM cells could be weaken and the sensitivity to temozolomide (TMZ) chemotherapy increased after knocking down ENTR1. Overexpression of ENTR1 could reverse this effect. RNA-seq analysis showed that tumor necrosis factor (TNF) signaling pathway might be a putative regulatory target of ENTR1. Tumor formation assay validated that ENTR1 was a significant factor in tumor growth. CONCLUSION: Our results indicated that ENTR1 played an important role in cell proliferation, invasion and chemotherapeutic sensitivity of GBM, suggesting that ENTR1 might be a novel prognostic marker and significant therapeutic target for GBM.

Paeoniflorin inhibits colorectal cancer cell stemness through the miR-3194-5p/catenin beta-interacting protein 1 axis.

Paeoniflorin (PF) is a natural plant ingredient with remarkable antitumor effects. Herein, we investigated the biological effects and mechanism of PF in colorectal cancer (CRC) cell stemness. The messenger RNA (mRNA) and protein expressions were assessed using quantitative real-time polymerase chain reaction and western blot. The viability, proliferation, and migration and invasion of CRC cells were evaluated using cell counting kit-8, clone-formation, and transwell migration and invasion assays, respectively. The sphere-formation capacity was determined using the sphere-formation assay. A dual-luciferase reporter gene assay was employed to analyze the interaction between miR-3194-5p and catenin beta-interacting protein 1 (CTNNBIP1). The viability, migration, invasion, epithelial-mesenchymal transition, and stemness of CRC cells were repressed by PF. MiR-3194-5p was upregulated in CRC tissues and cells. MiR-3194-5p knockdown suppressed CRC cell stemness, while miR-3194-5p overexpression had the opposite effect. In addition, the inhibition of CRC cell stemness caused by PF was eliminated by miR-3194-5p overexpression. CTNNBIP1 functioned as the target of miR-3194-5p, whose knockdown abrogated the repression of CRC cell stemness and Wnt/ß-catenin signaling activation by PF.PF regulated the miR-3194-5p/CTNNBIP1/Wnt/ß-catenin axis to repress CRC cell stemness.

Expression and functional activity of myosin II in hyperplastic prostates of varying volumes.

Prostate volume (PV) differs dramatically among benign prostatic hyperplasia (BPH) patients. Estimation of PV is important to guide the most appropriate pharmacologic or interventional treatment approach. However, the underlying pathophysiological mechanisms for the differences in PV remain unknown. We recently found that the myosin II system might participate in the etiology and development of BPH via static and dynamic factors. Our present study aims to explore the expression and functional activities of myosin II isoforms including smooth muscle (SM) myosin II (SMM II) and non-muscle myosin II (NMM II) in hyperplastic prostates with varied PV. Human hyperplastic prostates and the testosterone-induced rat BPH model were employed for this study. Hematoxylin and Eosin (H&E), Masson's trichrome, immunohistochemical staining, in vitro organ bath, RT-polymerase chain reaction (PCR) and Western-blotting were performed. Also, a BPH tissue microarray (TMA) was constructed to determine the correlations between myosin II isoforms with clinical parameters of BPH patients. With the increase of PV, the expression of NMMHC-A, NMMHC-C, SM-A and LC17b isoforms were increased, and the contractility of prostate smooth muscle was enhanced but force developed more slowly. Consistently, NMMHC-A, NMMHC-C, SM-A and LC17b were correlated positively with PV. Similar outcomes were also observed in the BPH rat model with different PVs. Alterations in the expression and function of myosin the II system may be involved in the pathophysiological mechanism of PV differences between BPH patients.

LILRB2-containing small extracellular vesicles from glioblastoma promote tumor progression by promoting the formation and expansion of myeloid-derived suppressor cells.

BACKGROUND: Leukocyte immunoglobulin-like receptor subfamily B2 (LILRB2) was reported to be an inhibitory molecule with suppressive functions. sEVs mediate communication between cancer cells and other cells. However, the existence of LILRB2 on sEVs in circulation and the function of sEVs-LILRB2 are still unknown. This study aims to investigate the role of LILRB2 in GBM and determine how LILRB2 in sEVs regulates tumor immunity. METHODS: LILRB2 expression in normal brain and GBM tissues was detected by immunohistochemistry, and the effect of LILRB2 on prognosis was evaluated in an orthotopic brain tumor model. Next, a subcutaneous tumor model was constructed to evaluate the function of pirb in vivo. The immune cells in the tumor sites and spleen were detected by immunofluorescence staining and flow cytometry. Then, the presence of pirb in sEVs was confirmed by WB. The percentage of immune cells after incubation with sEVs from GL261 (GL261-sEVs) or sEVs from GL261-pirb+ (GL261-sEVs-pirb) was detected by flow cytometry. Then, the effect of pirb on sEVs was evaluated by a tumor-killing assay and proliferation assay. Finally, subcutaneous tumor models were constructed to evaluate the function of pirb on sEVs. RESULTS: LILRB2 was overexpressed in human GBM tissue and was closely related to an immunosuppressive TME in GBM. Then, a protumor ability of LILRB2 was observed in subcutaneous tumor models, which was related to lower CD8 + T cells and higher MDSCs (myeloid-derived suppressor cells) in the tumor and spleen compared to those of the control group. Next, we found that pirb on sEVs (sEVs-pirb) inhibits the function of CD8 + T cells by promoting the formation and expansion of MDSCs. Furthermore, the protumor function of sEVs-pirb was demonstrated in subcutaneous tumor models. CONCLUSION: We discovered that LILRB2/pirb can be transmitted between GBM cells via sEVs and that pirb on sEVs induces the formation and expansion of MDSCs. The induced MDSCs facilitate the formation of an immunosuppressive TME.

DHCR7 promotes tumorigenesis via activating PI3K/AKT/mTOR signalling pathway in bladder cancer.

Bladder cancer (BCa) is a common malignancy with uncertain molecular mechanism. 7-dehydrocholesterol reductase (DHCR7), the enzyme of mammalian sterol biosynthesis, plays important roles in several types of cancers but its specific function in BCa is still unknown. The current study aimed to determine the bioinformatic characteristics and biological functions of DHCR7 in BCa. Sequencing results and clinical data from online public databases, human BCa tissues and matched noncancerous tissues, xenograft nude mice, DHCR7 deficiency and overexpression BCa cell (T24 and EJ) models were used. Several bioinformatics analyses were made, qRT-PCR, Western-blotting, flow cytometry, immunohistochemistry (IHC), MTT assay, wound healing and cell invasion assays were performed. It was found that DHCR7 was upregulated in BCa as an independent risk factor, and the expression of DHCR7 was associated with BCa grade and stage, finally resulted in poor prognosis. We further demonstrated that DHCR7 overexpression could accelerate the G0/G1 phase to accelerate the growth of tumor cells, antagonize cell apoptosis, and enhance the invasion and migration capacity, as well as EMT process via PI3K/AKT/mTOR signalling pathway, which could be completely reversed by DHCR7 knockdown. Finally, DHCR7 deficiency significantly decreased tumorigenesis in vivo. Our novel data demonstrated that DHCR7 could modulate BCa tumorigenesis in vitro and in vivo via PI3K/AKT/mTOR signalling pathway. It is suggested that DHCR7 might become a molecular target for the diagnosis and treatment of BCa.

Structural design and analysis of pneumatic prostate seed implantation robot applied in magnetic resonance imaging environment.

BACKGROUND: The method of MRI (Magnetic Resonance Imaging) image-guided robot for prostate seed implantation has developed rapidly in recent years. During the operation, although the puncture effect guided by MRI is very good, it is difficult for conventional robots driven by motors to work normally in this environment, which reduces the accuracy of seed implantation and affects the treatment effect. METHODS: First, this paper designs a pneumatic prostate seed implantation robot that is compatible with MRI; the robot is composed of an execution module and an adjustment module, and can complete the positioning and adjustment of the robot's needle entry point, the pose adjustment of the puncture needle and the completion of seed implantation in the MRI space; meanwhile, the statics simulation analysis of its key components is carried out. Then, the kinematics analysis was carried out according to the designed robot structure, and the relationship between the posture of the needle tip and the change of the pneumatic cylinder was obtained; meanwhile, using MATLAB 2020 software, combined with the method of Monte Carlo random number sampling, the simulation analysis of the workspace was carried out. Finally, an experimental prototype is constructed to conduct puncture accuracy experiments, workspace experiments and performance comparison tests in MRI environment. RESULTS: The statics simulation results verify that the key components of the robot designed in this paper can meet the strength requirements of the robot. The simulation results of the workspace meet the requirements of space surgery for prostate seed implantation under the guidance of MRI environment. The puncture accuracy experimented to verify that increasing the puncture speed can improve the seed implantation accuracy, and the puncture deviation of the robot is less than the average deviation of the doctor's actual operation by 6.5 mm. The working space experiment shows that the pitch range is -23.3°~27.8°, the movement range in the X direction is 0~210 mm, the movement range in the Y direction is 0~101 mm, and the lifting range in the Z direction is 0~81 mm, which meets the workspace requirements under MRI. The performance comparison test results in the MRI environment show that the robot is well compatible with MRI instruments. CONCLUSIONS: The pneumatic prostate seed implantation robot designed in this paper has a reasonable structure and stable dynamic performance output, and can perform precise surgical operations in the MRI strong magnetic environment. The research work in this paper provides a design reference for the related research on the positioning accuracy of minimally invasive puncture surgery guided by MRI images.

Piperlongumine combined with vitamin C as a new adjuvant therapy against gastric cancer regulates the ROS-STAT3 pathway.

OBJECTIVE: To investigate the effects of piperlongumine (PL) and vitamin C (VC) on signal transducer and activator of transcription 3 (STAT3) signalling in gastric cancer cell lines. METHODS: In vivo tumour xenograft anticancer assays were undertaken to confirm the anticancer activity of PL. Cell viability, flow cytometry and Western blot assays were undertaken to evaluate the anticancer effects of PL, VC and combinations of PL and VC in AGS and KATO III cells. RESULTS: Both PL and VC induced apoptosis and inhibited cell proliferation in AGS and KATO III cells. These effects were dependent on reactive oxygen species (ROS). PL effectively suppressed STAT3 activation while VC caused abnormal activation of STAT3. The combination of PL and VC exhibited a stronger apoptotic effect compared with either agent alone. PL reversed the abnormal activation of STAT3 by VC, which could be a key to their synergistic effect. CONCLUSIONS: PL combined with VC exhibited a stronger anticancer effect by regulating the ROS-STAT3 pathway, suggesting that this combination might be a potential adjuvant therapy for gastric cancer.

Eliminating the original cargos of glioblastoma cell-derived small extracellular vesicles for efficient drug delivery to glioblastoma with improved biosafety.

Tumor derived small extracellular vesicles (TsEVs) display a great potential as efficient nanocarriers for chemotherapy because of their intrinsic targeting ability. However, the inherited risks of their original cargos (like loaded proteins or RNAs) from parent cancer cells in tumor progression severely hinder the practical application. In this study, a saponin-mediated cargo elimination strategy was established and practiced in glioblastoma (GBM) cell-derived small extracellular vesicles (GBM-sEVs). A high eliminating efficacy of the cargo molecules was confirmed by systematic analysis of the original proteins and RNAs in GBM-sEVs. In addition, the inherited functions of GBM-sEVs to promote GBM progression vanished after saponin treatment. Moreover, the results of cellular uptake analysis and in vivo imaging analysis demonstrated that saponin treatment preserved the homotypic targeting ability of GBM-sEVs. Thus, we developed an efficient nanocarrier with improved biosafety for GBM suppression. Furthermore, doxorubicin (DOX) transported by the saponin-treated GBM-sEVs (sa-GBM-sEVs) displayed an effective tumor suppression in both subcutaneous and orthotopic GBM models of mouse. Collectively, this study provides a feasible way to avoid the potential protumoral risks of TsEVs and can advance the clinical application of TsEVs in chemotherapy.

Glucose-regulated protein 78 modulates cell growth, epithelial-mesenchymal transition, and oxidative stress in the hyperplastic prostate.

Benign prostatic hyperplasia (BPH) is a chronic condition which mainly affects elderly males. Existing scientific evidences have not completely revealed the pathogenesis of BPH. Glucose-regulated protein 78 (GRP78) is a member of the heat shock protein 70 superfamily, which serves as an important regulator in many diseases. This study aims at elucidating the role of GRP78 in the BPH process. Human prostate tissues, cultured human prostate cell lines (BPH-1 and WPMY-1) and clinical data from BPH patients were utilized. The expression and localization of GRP78 were determined with quantitative real time PCR (qRT-PCR), Western blotting and immunofluorescence staining. GRP78 knockdown and overexpression cell models were created with GRP78 siRNA and GRP78 plasmid transfection. With these models, cell viability, apoptosis rate, as well as marker levels for epithelial-mesenchymal transition (EMT) and oxidative stress (OS) were detected by CCK8 assay, flow cytometry analysis and Western blotting respectively. AKT/mTOR and MAPK/ERK pathways were also evaluated. Results showed GRP78 was localized in the epithelium and stroma of the prostate, with higher expression in BPH tissues. There was no significant difference in GRP78 expression between BPH-1 and WPMY-1 cell lines. In addition, GRP78 knockdown (KD) slowed cell growth and induced apoptosis, without effects on the cell cycle stage of both cell lines. Lack of GRP78 affected expression levels of markers for EMT and OS. Consistently, overexpression of GRP78 completely reversed all effects of knocking down GRP78. We further found that GRP78 modulated cell growth and OS via AKT/mTOR signaling, rather than the MAPK/ERK pathway. Overall, our novel data demonstrates that GRP78 plays a significant role in the development of BPH and suggests that GRP78 might be rediscovered as a new target for treatment of BPH.

Changes in the Expression and Functional Activities of C-X-C Motif Chemokine Ligand 13 (CXCL13) in Hyperplastic Prostate.

BACKGROUND: C-X-C motif chemokine ligand 13 (CXCL13), a member of the CXC subtype in chemokine superfamily, affects numerous biological processes of various types of cells and the progress of a great number of clinical diseases. The purpose of the current study was to reveal the internal mechanism between CXCL13 and benign prostatic hyperplasia (BPH). METHODS: Human serum, prostate tissues and human prostate cell lines (BPH-1, WPMY-1) were utilized. The effect of recombinant human CXCL13 (rHuCXCL13) protein and the influences of the knockdown/overexpression of CXCL13 on two cell lines were studied. Rescue experiments by anti-CXCR5 were also conducted. In vivo, rHuCXCL13 was injected into the ventral prostate of rats. Additionally, a tissue microarray of hyperplastic prostate tissues was constructed to analyze the correlations between CXCL13 and clinical parameters. RESULTS: CXCL13 was highly expressed in the prostate tissues and upregulated in the BPH group. It was observed that CXCL13 modulated cell proliferation, apoptosis, and the epithelial-mesenchymal transition (EMT) through CXCR5 via AKT and the ERK1/2 pathway in BPH-1, while it contributed to inflammation and fibrosis through CXCR5 via the STAT3 pathway in WPMY-1. In vivo, rHuCXCL13 induced the development of rat BPH. Additionally, CXCL13 was positively correlated with the prostate volume and total prostate specific antigen. CONCLUSIONS: Our novel data demonstrated that CXCL13 modulated cell proliferation, cell cycle, the EMT of epithelial cells, and induced the fibrosis of prostatic stromal cells via a variety of inflammatory factors, suggesting that CXCL13 might be rediscovered as a potential therapeutic target for the treatment of BPH.

Nickel-cobalt layered double hydroxide nanosheets anchored to the inner wall of wood carbon tracheids by nitrogen-doped atoms for high-performance supercapacitors.

In this paper, a novel type of electrode material for high-performance hybrid supercapacitors is designed. The electrode mainly uses nitrogen-doped atoms to anchor the nickel-cobalt layered double hydroxide on the inner wall of wood-derived carbon tracheids from Chinese fir wood scraps. The specific capacity of the composite single electrode is 14.26 mAh cm-2 at 10 mA cm-2. The hybrid supercapacitor with a composite electrode cathode and nitrogen-doped wood-derived monolithic carbon materials as the anode has a high specific capacitance of 4.74F cm-2 at 5 mA cm-2, and the capacitance retention rate is 93.15% after 8000 charge-discharge cycles. The highest energy density and power density reach 1.48 mWh cm-2 and 22.40 mW cm-2, respectively. After doping with nitrogen, the combination with the nickel-cobalt layered double hydroxide is more uniform and stable, and the capacitance and cycling stability are significantly improved.

Total Flavonoids Isolated from Diospyros kaki L. f. Leaves Induced Apoptosis and Oxidative Stress in Human Cancer Cells.

BACKGROUND/AIM: Persimmon (Diospyros kaki L.) leaves are popular as a tea infusion in Asia and their main active ingredients are flavonoids. The present study aimed to explore the anticancer properties of flavonoids isolated from persimmon leaves (PLF). MATERIALS AND METHODS: We investigated the in vitro anti-proliferative activity of PLF against several human cancer cell lines. Apoptosis and intracellular reactive oxygen species (ROS) induced by PLF were accessed using high-content analysis with florescent staining. The ability of PLF to scavenge free radicals was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. RESULTS: PLF demonstrated significant inhibition of proliferation of liver, breast, and colorectal cancer cells in vitro. PLF induced apoptosis and increased intracellular ROS levels in HCT116 (colorectal cancer) and HepG2 (liver cancer) cells. In addition, PLF showed strong free radical scavenging ability. CONCLUSION: The anti-proliferation activity of PLF against cancer cells was related to the induction of apoptosis and oxidative stress.

Recent Advances in Ginsenosides as Potential Therapeutics Against Breast Cancer.

The dried root of ginseng (Panax ginseng C. A. Meyer or Panax quinquefolius L.) is a traditional Chinese medicine widely used to manage cancer symptoms and chemotherapy side effects in Asia. The anti-cancer efficacy of ginseng is attributed mainly to the presence of saponins, which are commonly known as ginsenosides. Ginsenosides were first identified as key active ingredients in Panax ginseng and subsequently found in Panax quinquefolius, both of the same genus. To review the recent advances on anti-cancer effects of ginsenosides against breast cancer, we conducted a literature study of scientific articles published from 2010 through 2018 to date by searching the major databases including Pubmed, SciFinder, Science Direct, Springer, Google Scholar, and CNKI. A total of 50 articles authored in either English or Chinese related to the anti-breast cancer activity of ginsenosides have been reviewed, and the in vitro, in vivo, and clinical studies on ginsenosides are summarized. This review focuses on how ginsenosides exert their anti-breast cancer activities through various mechanisms of action such as modulation of cell growth, modulation of the cell cycle, modulation of cell death, inhibition of angiogenesis, inhibition of metastasis, inhibition of multidrug resistance, and cancer immunemodulation. In summary, recent advances in the evaluation of ginsenosides as therapeutic agents against breast cancer support further pre-clinical and clinical studies to treat primary and metastatic breast tumors.

A Prussian Blue ZnO Carbon Nanotube Composite for Chronoamperometrically Assaying H2O2 in BT20 and 4T1 Breast Cancer Cells.

A Prussian Blue (PB) zinc oxide carbon nanotube sensing composite was developed for the rapid assaying of H2O2 generated from BT20 and 4T1 breast cancer cells, important for elucidating mechanisms governing apoptosis of these cell lines. The combination of H2O2's transient nature along with matrix effects makes monitoring this molecule in biological samples a challenge. The standard addition method (SAM) was coupled with chronoamperometric sensing (CA) to overcome these obstacles. An electrocatalyst composite consisting of refluxed zinc oxide nanoparticles (NPs) tethered to carboxylic acid-functionalized multiwalled carbon nanotubes (ZnO/COOH-MWNTs) was electrostatically attached to PB for signal enhancement. Optimization of the sensor was achieved via adjusting solution pH and stirring time to optimize PB electrostatic attachment to ZnO/COOH-MWNTs prior to its deposition onto the working glassy carbon electrode (GCE) surface. CA SAM showed the ability to accurately measure H2O2 within the 1-21 µM range, suitable for monitoring cancer cell line apoptosis resistance scenarios and offering analytical advantages over standard enzyme-linked immunosorbent assays (ELISA) for rapid, matrix-effect-free analysis.

Preliminary study of single-operator cholangioscopy for diagnosing pancreatic cystic lesions.

BACKGROUND AND AIMS: Advances in imaging technology have improved the annual detection rate of pancreatic cystic lesions (PCLs), but the preoperative diagnosis of PCLs remains unclear. Thus, the usefulness of single-operator cholangioscopy (SOC) as a diagnostic imaging tool for PCLs is worth investigating. We performed an intracystic visual examination of PCLs using SOC to determine the diagnostic value of SOC for PCLs. METHODS: In this retrospective observational study, PCLs were confirmed using a diagnostic imaging modality. Patients who underwent an EUS-guided through-the-needle fiberoptic pancreatic cystoscopy and SOC examination and those whose lesion type was definitively diagnosed were included (n = 43). If the cystic fluid was turbid, a physiologic saline solution was injected into the cyst, and a SOC fiberoptic probe was inserted through a 19-gauge needle to observe the wall of the intracystic cavity and its contents. The characteristics were recorded, and the cystic fluid and biopsy specimens were further assessed by performing liquid-based cytologic and histopathologic examinations. Particularly, histopathologic examinations were performed in patients who underwent surgery. RESULTS: Intracystic characteristics of the confirmed cases of PCLs (43 patients) were identified through intracystic visual examination with SOC. The clarity of cyst fluid is a prerequisite for imaging by SOC. The tree-like branching pattern of blood vessel distribution may be a serous cystic neoplasm-specific characteristic. Intracystic papilla-like structure is an important characteristic for diagnosing mucinous cystic neoplasms. CONCLUSIONS: The identified imaging characteristics such as blood vessel distribution on the intracystic wall and the contents of different PCLs observed under the SOC probe can provide useful information for diagnosing PCLs. SOC could be an important ancillary imaging test of PCLs by EUS.