A prototype protein nanocage minimized from carboxysomes with gated oxygen permeability.

Protein nanocages (PNCs) in cells and viruses have inspired the development of self-assembling protein nanomaterials for various purposes. Despite the successful creation of artificial PNCs, the de novo design of PNCs with defined permeability remains challenging. Here, we report a prototype oxygen-impermeable PNC (OIPNC) assembled from the vertex protein of the ß-carboxysome shell, CcmL, with quantum dots as the template via interfacial engineering. The structure of the cage was solved at the atomic scale by combined solid-state NMR spectroscopy and cryoelectron microscopy, showing icosahedral assembly of CcmL pentamers with highly conserved interpentamer interfaces. Moreover, a gating mechanism was established by reversibly blocking the pores of the cage with molecular patches. Thus, the oxygen permeability, which was probed by an oxygen sensor inside the cage, can be completely controlled. The CcmL OIPNC represents a PNC platform for oxygen-sensitive or oxygen-responsive storage, catalysis, delivery, sensing, etc.

Unraveling the Transformation from Type-II to Z-Scheme in Perovskite-Based Heterostructures for Enhanced Photocatalytic CO2 Reduction.

The ability to create perovskite-based heterostructures with desirable charge transfer characteristics represents an important endeavor to render a set of perovskite materials and devices with tunable optoelectronic properties. However, due to similar material selection and band alignment in type-II and Z-scheme heterostructures, it remains challenging to obtain perovskite-based heterostructures with a favorable electron transfer pathway for photocatalysis. Herein, we report a robust tailoring of effective charge transfer pathway in perovskite-based heterostructures via a type-II to Z-scheme transformation for highly efficient and selective photocatalytic CO2 reduction. Specifically, CsPbBr3/TiO2 and CsPbBr3/Au/TiO2 heterostructures are synthesized and then investigated by ultrafast spectroscopy. Moreover, taking CsPbBr3/TiO2 and CsPbBr3/Au/TiO2 as examples, operando experiments and theoretical calculations confirm that the type-II heterostructure could be readily transformed into a Z-scheme heterostructure through establishing a low-resistance Ohmic contact, which indicates that a fast electron transfer pathway is crucial in Z-scheme construction, as further demonstrated by CsPbBr3/Ag/TiO2 and CsPbBr3/MoS2 heterostructures. In contrast to pristine CsPbBr3 and CsPbBr3/TiO2, the CsPbBr3/Au/TiO2 heterostructure exhibits 5.4- and 3.0-fold enhancement of electron consumption rate in photocatalytic CO2 reduction. DFT calculations and in situ diffuse reflectance infrared Fourier transform spectroscopy unveil that the superior CO selectivity is attributed to the lower energy of *CO desorption than that of hydrogenation to *HCO. This meticulous design sheds light on the modification of perovskite-based multifunctional materials and enlightens conscious optimization of semiconductor-based heterostructures with desirable charge transfer for catalysis and optoelectronic applications.

Programmable Singlet Oxygen Battery for Automated Photodynamic Therapy Enabled by Pyridone-Pyridine Tautomer Engineering.

The efficacy of photodynamic therapy is hindered by the hypoxic environment in tumors and limited light penetration depth. The singlet oxygen battery (SOB) has emerged as a promising solution, enabling oxygen- and light-independent 1O2 release. However, conventional SOB systems typically exhibit an "always-ON" 1O2 release, leading to potential 1O2 leakage before and after treatment. This not only compromises therapeutic outcomes but also raises substantial biosafety concerns. In this work, we introduce a programmable singlet oxygen battery, engineered to address all the issues discussed above. The concept is illustrated through the development of a tumor-microenvironment-responsive pyridone-pyridine switch, PyAce, which exists in two tautomeric forms: PyAce-0 (pyridine) and PyAce (pyridone) with different 1O2 storage half-lives. In its native state, PyAce remains in the pyridone form, capable of storing 1O2 (t1/2 = 18.5 h). Upon reaching the tumor microenvironment, PyAce is switched to the pyridine form, facilitating rapid and thorough 1O2 release (t1/2 = 16 min), followed by quenched 1O2 release post-therapy. This mechanism ensures suppressed 1O2 production pre- and post-therapy with selective and rapid 1O2 release at the tumor site, maximizing therapeutic efficacy while minimizing side effects. The achieved "OFF-ON-OFF" 1O2 therapy showed high spatiotemporal selectivity and was independent of the oxygen supply and light illumination.

Capsule Shedding and Membrane Binding Enhanced Photodynamic Killing of Gram-Negative Bacteria by a Unimolecular Conjugated Polyelectrolyte.

The development of new antimicrobial agents to treat infections caused by Gram-negative bacteria is of paramount importance due to increased antibiotic resistance worldwide. Herein, we show that a water-soluble porphyrin-cored hyperbranched conjugated polyelectrolyte (PorHP) exhibits high photodynamic bactericidal activity against the Gram-negative bacteria tested, including a multidrug-resistant (MDR) pathogen, while demonstrating low cytotoxicity toward mammalian cells. Comprehensive analyses reveal that the antimicrobial activity of PorHP proceeds via a multimodal mechanism by effective bacterial capsule shedding, strong bacterial outer membrane binding, and singlet oxygen generation. Through this multimodal antimicrobial mechanism, PorHP displays significant performance for Gram-negative bacteria with >99.9% photodynamic killing efficacy. Overall, PorHP shows great potential as an antimicrobial agent in fighting the growing threat of Gram-negative bacteria.

Mechanisms of portal vein tumour thrombus formation and development in patients with hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most common and aggressive human malignancies worldwide. Portal vein tumour thrombus (PVTT) is considered one of most fearful complications of HCC and is strongly associated with a poor prognosis. Clarification of the mechanisms underlying the formation and development of PVTT is crucial for developing novel therapeutic strategies for HCC patients. Several studies have been made to uncover that tumour microenvironment, stem cells, abnormal gene expression and non-coding RNAs deregulation are associated with PVTT in patients with HCC in the last decade. However, the exact molecular mechanisms of PVTT in patients with HCC are still largely unknown. In the present review, we briefly summarized the molecular mechanisms underlying the formation and development of PVTT in HCC.

Small-Molecule Phototheranostic Agent with Extended π-Conjugation for Efficient NIR-II Photoacoustic-Imaging-Guided Photothermal Therapy.

Photoacoustic imaging (PAI) and photothermal therapy (PTT) conducted over the near-infrared-II (NIR-II) window offer the benefits of noninvasiveness and deep tissue penetration. This necessitates the development of highly effective therapeutic agents with NIR-II photoresponsivity. Currently, the predominant organic diagnostic agents used in NIR-II PAI-guided PTT are conjugated polymeric materials. However, they exhibit a low in vivo clearance rate and long-term biotoxicity, limiting their clinical translation. In this study, an organic small molecule (CY-1234) with NIR-II absorption and nanoencapsulation (CY-1234 nanoparticles (NPs)) for PAI-guided PTT is reported. Extended π-conjugation is achieved in the molecule by introducing donor-acceptor units at both ends of the molecule. Consequently, CY-1234 exhibits a maximum absorption peak at 1234 nm in tetrahydrofuran. Nanoaggregates of CY-1234 are synthesized via F-127 encapsulation. They exhibit an excellent photothermal conversion efficiency of 76.01% upon NIR-II light irradiation. After intravenous injection of CY-1234 NPs into tumor-bearing mice, strong PA signals and excellent tumor ablation are observed under 1064 nm laser irradiation. This preliminary study can pave the way for the development of small-molecule organic nanoformulations for future clinical applications.

KHDRBS3 accelerates glycolysis and promotes malignancy of hepatocellular carcinoma via upregulating 14-3-3ζ.

BACKGROUND: Primary hepatocellular carcinoma (HCC) is a malignancy with high morbidity and mortality. KH domain-containing, RNA-binding signal transduction-associated protein 3 (KHDRBS3) is an RNA-binding protein that is aberrantly expressed in multiple tumors; however, its expression and biological function in HCC have not been reported. METHODS: KHDRBS3 knockdown and overexpression were performed using the lentiviral vector system to investigate the effects of KHDRBS3 on cell proliferation, apoptosis, chemoresistance, and glycolysis. Murine xenograft tumor models were constructed to study the role of KHDRBS3 on tumor growth in vivo. Furthermore, RNA-Pull Down and RNA immunoprecipitation were utilized to explore the interaction between KHDRBS3 and 14-3-3ζ, a phosphopeptide-binding molecule encoded by YWHAZ. RESULTS: KHDRBS3 was highly expressed in human HCC tissues and predicted the poor prognosis of patients with HCC. Knockdown of KHDRBS3 exhibited a carcinostatic effect in HCC and impeded proliferation and tumor growth, reduced glycolysis, enhanced cell sensitivity to doxorubicin, and induced apoptosis. On the contrary, forced expression of KHDRBS3 expedited the malignant biological behaviors of HCC cells. The expression of KHDRBS3 was positively correlated with the expression of 14-3-3ζ. RNA immunoprecipitation and RNA pull-down assays demonstrated that KHDRBS3 bound to YWHAZ. We further confirmed that 14-3-3ζ silencing significantly reversed the promotion of proliferation and glycolysis and the inhibition of apoptosis caused by KHDRBS3 overexpression. CONCLUSIONS: Our findings suggest that KHDRBS3 promotes glycolysis and malignant progression of HCC through upregulating 14-3-3ζ expression, providing a possible target for HCC therapy.

Risk factor analysis and prediction of postoperative clinically relevant pancreatic fistula after distal pancreatectomy.

OBJECTIVE: Postoperative pancreatic fistula (POPF) following distal pancreatectomy (DP) is a serious complication. In the present study, we aimed to identify the risk factors associated with clinically relevant postoperative pancreatic fistula (CR-POPF) and establish a nomogram model for predicting CR-POPF after DP. METHODS: In total, 115 patients who underwent DP at the General Hospital of Northern Theater Command between January 2005 and December 2020 were retrospectively studied. Univariate and multivariable logistic regression analyses were used to identify the independent risk factors associated with CR-POPF. Then, a nomogram was formulated based on the results of multivariable logistic regression analysis. The predictive performance was evaluated with receiver operating characteristic (ROC) curves. Decision curve and clinical impact curve analyses were used to validate the clinical application value of the model. RESULTS: The incidence of CR-POPF was 33.0% (38/115) in the present study. Multivariate logistic regression analysis identified the following variables as independent risk factors for POPF: body mass index (BMI) (OR 4.658, P = 0.004), preoperative albumin level (OR 7.934, P = 0.001), pancreatic thickness (OR 1.256, P = 0.003) and pancreatic texture (OR 3.143, P = 0.021). We created a nomogram by incorporating the above mentioned risk factors. The nomogram model showed better predictive value, with a concordance index of 0.842, sensitivity of 0.710, and specificity of 0.870 when compared to each risk factor. Decision curve and clinical impact curve analyses also indicated that the nomogram conferred a high clinical net benefit. CONCLUSION: Our nomogram could accurately and objectively predict the risk of postoperative CR-POPF in individuals who underwent DP, which could help clinicians with early identification of patients who might develop CR-POPF and early development of a suitable fistula mitigation strategy and postoperative management.

Activatable Type I Photosensitizer with Quenched Photosensitization Pre and Post Photodynamic Therapy.

The phototoxicity of photosensitizers (PSs) pre and post photodynamic therapy (PDT), and the hypoxic tumor microenvironment are two major problems limiting the application of PDT. While activatable PSs can successfully address the PS phototoxicity pre PDT, and type I PS can generate reactive oxygen species (ROS) effectively in hypoxic environment, very limited approaches are available for addressing the phototoxicity post PDT. There is virtually no solution available to address all these issues using a single design. Herein, we propose a proof-of-concept on-demand switchable photosensitizer with quenched photosensitization pre and post PDT, which could be activated only in tumor hypoxic environment. Particularly, a hypoxia-normoxia cycling responsive type I PS TPFN-AzoCF3 was designed to demonstrate the concept, which was further formulated into TPFN-AzoCF3 nanoparticles (NPs) using DSPE-PEG-2000 as the encapsulation matrix. The NPs could be activated only in hypoxic tumors to generate type I ROS during PDT treatment, but remain non-toxic in normal tissues, pre or after PDT, thus minimizing side effects and improving the therapeutic effect. With promising results in in vitro and in vivo tumor treatment, this presented strategy will pave the way for the design of more on-demand switchable photosensitizers with minimized side effects in the future.

Real-Time Quantification of Cartilage Degeneration by GAG-Targeted Cationic Nanoparticles for Efficient Therapeutic Monitoring in Living Mice.

One of the characterizations of degenerative cartilage disease is the progressive loss of glycosaminoglycans (GAGs). The real-time imaging method to quantify GAGs is of great significance for the biochemical analysis of cartilage and diagnosis and therapeutic monitoring of cartilage degeneration in vivo. To this end, a cationic photoacoustic (PA) contrast agent, poly-l-lysine melanin nanoparticles (PLL-MNPs), specifically targeting anionic GAGs was developed in this study to investigate whether it can image cartilage degeneration. PLL-MNP assessed GAG depletion by Chondroitinase ABC in vitro rat cartilage and intact ex vivo mouse knee joint. A papain-induced cartilage degenerative mice model was used for in vivo photoacoustic imaging (PAI). Oral cartilage supplement glucosamine sulfate was intragastrically administered for mice cartilage repair and the therapeutic efficacy was monitored by PLL-MNP-enhanced PAI. Histologic findings were used to further confirm PAI results. In vitro results revealed that the PLL-MNPs not only had a high binding ability with GAGs but also sensitively monitored GAG content changes by PAI. The PA signal was gradually weakened along with the depletion of GAGs in cartilage. Particularly, PLL-MNPs depicted the cartilage structure and the distribution of GAGs was demonstrated in PA images in ex vivo joints. Compared with the normal joint, a lower signal intensity was detected from degenerative joint at 3 weeks after papain injection, suggesting an early diagnosis of cartilage lesion by PLL-MNPs. Importantly, this PA-enhanced nanoprobe was suitable for monitoring in vivo efficacy of glucosamine sulfate, which effectively blocked cartilage degradation in a high dose manner. In vivo imaging findings correlated well with histological examinations. PLL-MNPs provided sensitive visualization of cartilage degeneration and promising monitoring of therapeutic response in living subjects.

Impact of spontaneous splenorenal shunt on liver volume and long-term survival of liver cirrhosis.

BACKGROUND AND AIM: Spontaneous splenorenal shunt (SSRS) is one of the manifestations of portal hypertension in liver cirrhosis. However, the impact of SSRS on long-term survival of cirrhotic patients remains unclear. We hypothesize that SSRS may worsen liver dysfunction and deteriorate prognosis in liver cirrhosis by decreasing hepatic perfusion. METHODS: Patients with liver cirrhosis who were admitted to our department between December 2014 and August 2019 and underwent contrast-enhanced computed tomography or magnetic resonance imaging scans were prospectively collected. The maximum diameters of SSRS and portal vein system vessels were retrospectively measured. Liver-to-abdominal area ratio, Child-Pugh, and model for end-stage liver disease scores were calculated. RESULTS: Overall, 122 cirrhotic patients were included. The prevalence of SSRS was 30.3% (37/122). Median diameter of SSRS was 13.5 mm. Patients with SSRS had significantly thinner diameters of right portal vein (9 mm vs 11.2 mm, P = 0.001) and main portal vein (15.3 mm vs 16.8 mm, P = 0.017) than those without SSRS. Patients with SSRS had significantly lower liver-to-abdominal area ratio score (25.39 vs 31.58, P < 0.001) and higher Child-Pugh (7 vs 6, P = 0.046) and model for end-stage liver disease (12.17 vs 9.79, P < 0.006) scores than those without SSRS. Patients with SSRS had a significantly lower cumulative survival rate than those without SSRS (P = 0.014). Cox regression analysis also showed that SSRS was a risk factor of death of cirrhotic patients (hazard ratio = 4.161, 95% confidence interval = 1.215-14.255, P = 0.023). CONCLUSIONS: Spontaneous splenorenal shunt may narrow portal vein diameter and shrink liver volume, thereby worsening liver function and increasing mortality in liver cirrhosis.

14-3-3ζ binds to and stabilizes phospho-beclin 1S295 and induces autophagy in hepatocellular carcinoma cells.

Data from The Cancer Genome Atlas (TCGA) indicate that the expression levels of 14-3-3ζ and beclin 1 (a key molecule involved in cellular autophagy) are up-regulated and positively correlated with each other (R = .5, P < .05) in HCC tissues. Chemoresistance developed in hepatoma cancer cells is associated with autophagy initiation. This study aimed to explore 14-3-3ζ's role in regulating autophagy in HCC cells, with a focus on beclin 1. The co-localization of 14-3-3ζ and beclin 1 was detectable in primary HCC tissues. To simulate in vivo tumour microenvironment (hypoxia), CSQT-2 and HCC-LM3 cells were exposed to 2% oxygen for 24 hours. The protein levels of 14-3-3ζ and phospho-beclin 1S295 peaked at 12 hours following hypoxia. Meanwhile, the strongest autophagy flux occurred: LC3II was increased, and p62 was decreased significantly. By sequencing the coding area of BECN 1 gene of CSQT-2 and HCC-LM3 cells, we found that the predicted translational products of BECN 1 gene contained RLPS295 VP (R, arginine; L, leucine; P, proline; S, serine; V, valine), a classic 14-3-3ζ binding motif. CO-IP results confirmed that 14-3-3ζ bound to beclin 1, and this connection was markedly weakened when S295 was mutated into A295 (alanine). Further, 14-3-3ζ overexpression prevented phospho-beclin 1S295 from degradation and enhanced its binding to VPS34, whilst its knockdown accelerated the degradation. Additionally, 14-3-3ζ enhanced the chemoresistance of HCC cells to cis-diammined dichloridoplatium by activating autophagy. Our work reveals that 14-3-3ζ binds to and stabilizes phospho-beclin 1S295 and induces autophagy in HCC cells to resist chemotherapy.

LncRNA SNHG4 promotes the proliferation, migration, invasiveness, and epithelial-mesenchymal transition of lung cancer cells by regulating miR-98-5p.

Long noncoding RNA small nucleolar RNA host gene 4 (SNHG4) is usually up-regulated in cancer and regulates the malignant behavior of cancer cells. However, its role in lung cancer remains elusive. In this study, we silenced the expression of SNHG4 in NCI-H1437 and SK-MES-1, two representative non-small-cell lung cancer cell lines, by transfecting them with siRNA (small interfering RNA) that specifically targets SNHG4. We observed significantly inhibited cell proliferation in vitro and reduced tumor growth in vivo after SNHG4 silencing. SNHG4 knockdown also led to cell cycle arrest at the G1 phase, accompanied with down-regulation of cyclin-dependent kinases CDK4 and CDK6. The migration and invasiveness of these two cell lines were remarkably inhibited after SNHG4 silencing. Moreover, our study revealed that the epithelial-mesenchymal transition (EMT) of lung cancer cells was suppressed by SNHG4 silencing, as evidenced by up-regulated E-cadherin and down-regulated SALL4, Twist, and vimentin. In addition, we found that SNHG4 silencing induced up-regulation of miR-98-5p. MiR-98-5p inhibition abrogated the effect of SNHG4 silencing on proliferation and invasion of lung cancer cells. In conclusion, our findings demonstrate that SNHG4 is required by lung cancer cells to maintain malignant phenotype. SNHG4 probably exerts its pro-survival and pro-metastatic effects by sponging anti-tumor miR-98-5p.

Overexpression of PCK1 Gene Antagonizes Hepatocellular Carcinoma Through the Activation of Gluconeogenesis and Suppression of Glycolysis Pathways.

BACKGROUND/AIMS: Gluconeogenesis, a reverse process of glycolysis, is suppressed in neoplastic livers. Cytoplasmic phosphoenolpyruvate carboxykinase (PEPCK-C/PCK1, encoded by PCK1) is a step limiting enzyme of gluconeogenesis. The induced expression of the factor is reported to initiate gluconeogenesis process and antagonize hepatocellular carcinoma (HCC). In the current study, the effect of the modulation of PCK1 expression on HCC was assessed. METHODS: The levels of PCK1 in clinical HCC tissues and different HCC cell lines were investigated with real time quantitative PCR, immunochemistry, and western blotting. Thereafter, the expression of PCK1 gene was induced in two HCC cell lines and the effect of the overexpression on proliferation and migration potentials of HCC cells was detected with CCK-8 assay, flow cytometry, TUNEL staining, and transwell assay. The activities of glycolysis and gluconeogenesis pathways in PCK1-overexpressed HCC cell lines were detected with specific kits to underlie the mechanism by which PCK1 exerted its function. The results of the in vitro experiments were validated with HCC xenograft rat models. RESULTS: The expression levels of PCK1 were suppressed in HCC samples and in cells derived from HCC tissues. According to the results of the in vitro assays, the overexpression of PCK1 decreased viability, induced apoptosis, and inhibited migration in both HCC cell lines. The effect was associated with the suppressed glycolysis and the induced gluconeogenesis pathways, represented by the enhanced production of glucose and the limited production of pyruvic acid, lactate, citrate, and malate. The results of the in vitro assays were confirmed in rat models in that the growth rate of solid HCC tumors was reduced in mice transplanted with PCK1-overexpressed HCC cells. CONCLUSION: Findings outlined in the current study demonstrated that activating gluconeogenesis process via PCK1 overexpression was a potential treating strategy against HCC.

Co-Upregulation of 14-3-3ζ and P-Akt is Associated with Oncogenesis and Recurrence of Hepatocellular Carcinoma.

BACKGROUND/AIMS: 14-3-3ζ is involved in the regulation of PI3K/Akt pathway which is closely associated with carcinogenesis. However, the clinical significance of combined detection of 14-3-3ζ and p-Akt in hepatocellular carcinoma (HCC) remains unclear. METHODS: Two-hundred pairs of HCC and adjacent liver specimens were subjected to tissue microarray. The association of 14-3-3ζ and p-Akt levels with the postoperative survival and recurrence in HCC patients was analyzed with univariate and multivariate methods. Moreover, the effects of 14-3-3ζ overexpression on the growth of HCC and the expressions of p-Akt and HIF-1α were assessed in a xenograft mouse model. RESULTS: Elevated levels of 14-3-3ζ and p-Akt were detected in HCC and a positive correlation between the levels of 14-3-3ζ and p-Akt was verified. HCC patients with satellite nodules, microvascular invasion, portal vein tumor thrombosis, poor tumor differentiation and an advanced tumor stage tended to have higher levels of 14-3-3ζ and p-Akt. In addition, the postoperative 3-, 5-, and 7-year overall survival rates in HCC patients with 14-3-3ζhigh and p-Akthigh were significantly lower compared with those with 14-3-3ζlow and p-Aktlow, and the cumulative recurrence rate in HCC patients with 14-3-3ζhigh and p-Akthigh was significantly higher than that in those with 14-3-3ζlow and p-Aktlow. The multivariate Cox proportional hazard analysis indicated that concomitant upregulation of 14-3-3ζ and p-Akt was an independent factor that predicted poor survival and high recurrence in HCC patients. Furthermore, animal experiment showed that overexpression of 14-3-3ζ accelerated the growth of HCC xenograft tumors and induced the expressions of p-Akt and HIF-1α in vivo. CONCLUSION: Co-upregulation of 14-3-3ζ and p-Akt predicts poor prognosis in patients with HCC, and 14-3-3ζ-induced activation of the Akt signaling pathway contributes to HCC progression.

A Single Composition Architecture-Based Nanoprobe for Ratiometric Photoacoustic Imaging of Glutathione (GSH) in Living Mice.

As one of the reduction species, glutathione (GSH) plays a tremendous role in regulating the homeostasis of redox state in living body. Accurate imaging of GSH in vivo is highly desired to provide a real-time visualization of physiological and pathological conditions while it is still a big challenge. Recently developed photoacoustic imaging (PAI) with high resolution and deep penetration characteristics is more promising for in vivo GSH detection. However, its application is dramatically limited by the difficult designation of photoacoustic probes with changeable near-infrared (NIR)-absorption under reductive activation. A cyanine derivative-based activatable probe is developed for in vivo ratiometric PAI of GSH for the first time. The probe is structurally designed to output ratiometric signals toward GSH in NIR-absorption region based on the cleavage of disulfide bond followed by a subsequent exchange between the secondary amine and sulfydryl group formed. Such a ratiometric manner provides high signal-to-noise imaging of blood vessels and their surrounding areas in tumor. Concomitantly, it also exhibits good specificity toward GSH over other thiols. Furthermore, the single composition architecture of the probe effectively overcomes the leakage issue compared with traditional multicomposition architecture-based nanoprobe, thus enhancing the imaging accuracy and fidelity in living body.

The toxicity of continuous long-term low-dose formaldehyde inhalation in mice.

Although the toxicity of high-dose formaldehyde (FA) inhalation has been extensively analyzed in animals, the effect of continuous long-term exposure to low-dose FA has not been well documented. This study aims to evaluate the toxicity of continuous long-term low-dose FA inhalation in mice. Forty-eight Kunming male mice were equally randomized to three groups according to the dose of FA inhalation exposure: a control (0 mg/m3) group, a low-dose (0.08 mg/m3) group and a high-dose (0.8 mg/m3) group. The mice have been selected to expose to FA for different consecutive days at 24 h/day. The learning and memory functions, pathological changes in the lung and liver, and the percentage of CD4 + T and CD8 + T cells were observed and analyzed. It was found that continuous long-term inhalation of FA at relatively low doses could impair the learning and memory functions and induce pathological changes in the lung and liver, but did not seem to significantly affect the number of immune (CD4 + T and CD8 + T) cells.

Experimental study on enhancement of the metastatic potential of portal vein tumor thrombus-originated hepatocellular carcinoma cells using portal vein serum.

OBJECTIVE: Portal vein metastasis of hepatocellular carcinoma (HCC) results in a poor prognosis and seriously affects the survival rate of patients. The mechanism underlying the formation of portal vein tumor thrombus (PVTT) is complex and is not yet fully understood. This study was conducted to investigate the impact of portal vein blood on the proliferation, metastasis, invasion and apoptosis of PVTT cells and to explore its possible mechanisms, which was expected to lay a foundation for ascertaining the mechanism underlying the portal vein metastasis of HCC. METHODS: Peripheral blood and portal vein blood were collected from patients with HCC, and the sera from these two sources were used to culture the PVTT-originated HCC cell line CSQT-2. The cells were collected after 24 h, and flow cytometry was performed to detect cell proliferation, cell cycle stages and apoptosis. Transwell migration and invasion assays were applied to detect the metastasis and invasion of the cells in each group. The changes in the expression of MMP-2 and MMP-9 in cells were detected via Western blotting. The contents of IL-12, IFN-γ, IL-1ß, IL-2 and TNF-α in the two groups of sera were quantified using corresponding kits. RESULTS: Compared with the group of cells cultured with peripheral serum, the cells cultured with portal vein serum showed significantly lower apoptosis (P<0.01), significantly enhanced cell metastasis and invasion (P<0.01), whereas cell proliferation and the stages of the cell cycle did not differ significantly (P>0.05). A significantly increased expression level of MMP-2 has been observed in tumor cells treated portal vein serum. In addition, compared with peripheral serum, the content of IL-12 was significantly decreased in portal vein serum (P<0.05), while the contents of IFN-γ, IL-1ß, IL-2, and TNF-α did not differ significantly (P>0.05). CONCLUSIONS: Portal vein serum from HCC patients could inhibit the apoptosis of PVTT-originated HCC cells and promote cell metastasis and invasion. This effect may be related to the lower level of IL-12 in portal vein serum.