A positive feedback loop between Periostin and TGFβ1 induces and maintains the stemness of hepatocellular carcinoma cells via AP-2α activation

Background

Liver cancer stem cells (LCSCs) play key roles in the metastasis, recurrence, and chemotherapeutic resistance of hepatocellular carcinoma (HCC). Our previous research showed that the POSTN gene is closely related to the malignant progression and poor prognosis of HCC. This study aimed to elucidate the role of POSTN in generating LCSCs and maintaining their stemness as well as the underlying mechanisms.

Methods

Human HCC tissues and matched adjacent normal tissues were obtained from 110 patients. Immunohistochemistry, western blotting (WB), and RT-PCR were performed to detect the expression of POSTN and stemness factors. The roles of transforming growth factor (TGF)-β1 and AP-2α in the POSTN-induced stemness transformation of HCC cells were explored in vitro and in vivo using LCSCs obtained by CD133⁺ cell sorting.

Results

The high expression of POSTN was correlated with the expression of various stemness factors, particularly CD133, in our HCC patient cohort and in TCGA and ICGC datasets. Knockdown of POSTN expression decreased the abilities of HCC cell lines to form tumours in xenograft mouse models. Knockdown of POSTN expression also suppressed cell viability and clone formation, invasion, and sphere formation abilities in vitro. Knockdown of AP-2α attenuated the generation of CD133⁺ LCSCs and their malignant behaviours, indicating that AP-2α was a critical factor that mediated the POSTN-induced stemness transformation and maintenance of HCC cells. The role of AP-2α was verified by using a specific αvβ3 antagonist, cilengitide, in vitro and in vivo. Activation of POSTN could release TGFβ1 from the extracellular matrix and initiated POSTN/TGFβ1 positive feedback signalling. Furthermore, we found that the combined use of cilengitide and lenvatinib suppressed the growth of HCC cells with high POSTN expression more effectively than the use of lenvatinib alone in the patient-derived xenograft (PDX) mouse model.

Conclusions

The POSTN/TGFβ1 positive feedback pathway regulates the expression of stemness factors and the malignant progression of HCC cells by regulating the transcriptional activation of AP-2α. This pathway may serve as a new target for targeted gene therapy in HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-02011-8.

Isocorydine suppresses doxorubicin-induced epithelial-mesenchymal transition via inhibition of ERK signaling pathways in hepatocellular carcinoma

Doxorubicin (DOX) is a conventional and effective chemotherapeutic used in the treatment of hepatocellular carcinoma (HCC). However, doxorubicin administration may induce EMT, which results in the development of chemoresistance in HCC. Recent studies report that Isocorydine (ICD) selectively inhibits human cancer stem cells (CSCs), which have an important role in the development of chemoresistance. In this study, we observed that ICD co-administration enhanced DOX cytotoxicity in HCC cells, enabling the inhibition of DOX-induced epithelial-mesenchymal transition (EMT). Microarray data analysis revealed substantially decreased ERK signaling after ICD treatment. Additionally, we observed decreased IC₅₀ for DOX upon ERK knockdown. Finally, we confirmed the enhanced efficacy of treatment with a combination of DOX and ICD in xenograft models. Collectively, the present study unveils the benefit of using DOX in combination with ICD for chemotherapy against HCC, revealing a novel potential anti-cancer strategy.

Molecular cloning and characterization of a proliferating cell nuclear antigen gene by chemically induced male sterility in wheat (Triticum aestivum L.)

Although a number of studies have shown that chemical hybridizing agents (CHAs) affect anther growth and regulate cell-cycle progression, little is known about the molecular and cellular mechanisms involved. Proliferating cell nuclear antigen (PCNA) is an essential factor in DNA replication, and in many other processes in eukaryotic cells. In this study, the open reading frame of TaPCNA, the PCNA in wheat (Triticum aestivum L.), was cloned by reverse transcription polymerase chain reaction (RT-PCR). Sequence analysis revealed that this gene was 792-bp long and encoded a protein with 234 amino acids. Alignment of the TaPCNA-predicted sequence revealed a high degree of identity with PCNAs from other plant species. A subcellular localization assay indicated that TaPCNA was localized in the nucleus. The TaPCNA was cloned into the prokaryotic expression plasmid pET32a, and the recombinant plasmid was transformed into BL21 (DE3). TaPCNA expression was induced by 0.5 mM isopropyl-beta-D-thiogalactopyranoside and verified using sodium dodecyl sulfate polyacrylamide gel electrophoresis and western blot assays, which indicated that the fusion protein was successfully expressed. The gene involved in the G1-to-S transition, Histone H4, was downregulated by 1376- CIMS, which is a chemically induced male sterility line. However, a semi-quantitative RT-PCR revealed that TaPCNA expression was upregulated in 1376-CIMS. Our results suggest that CHAs (SQ-1) induce DNA damage in wheat anthers. DNA damage results in either the delay or arrest of cell-cycle progression, which affects anther development. This study will help to elucidate the mechanisms of SQ-1-induced male sterility.

Runoff characteristics and non-point source pollution analysis in the Taihu Lake Basin: a case study of the town of Xueyan, China

Non-point source pollution is a significant environmental issue in small watersheds in China. To study the effects of rainfall on pollutants transported by runoff, rainfall was monitored in Xueyan town in the Taihu Lake Basin (TLB) for over 12 consecutive months. The concentrations of different forms of nitrogen (N) and phosphorus (P), and chemical oxygen demand, were monitored in runoff and river water across different land use types. The results indicated that pollutant loads were highly variable. Most N losses due to runoff were found around industrial areas (printing factories), while residential areas exhibited the lowest nitrogen losses through runoff. Nitrate nitrogen (NO3-N) and ammonia nitrogen (NH4-N) were the dominant forms of soluble N around printing factories and hotels, respectively. The levels of N in river water were stable prior to the generation of runoff from a rainfall event, after which they were positively correlated to rainfall intensity. In addition, three sites with different areas were selected for a case study to analyze trends in pollutant levels during two rainfall events, using the AnnAGNPS model. The modeled results generally agreed with the observed data, which suggests that AnnAGNPS can be used successfully for modeling runoff nutrient loading in this region. The conclusions of this study provide important information on controlling non-point source pollution in TLB.

Effects of plant roots on the hydraulic performance during the clogging process in mesocosm vertical flow constructed wetlands

The aim of this study was to evaluate the effects of plant roots (Typha angustifolia roots) on the hydraulic performance during the clogging process from the perspective of time and space distributions in mesocosm vertical flow-constructed wetlands with coarse sand matrix. For this purpose, a pair of lab-scale experiments was conducted to compare planted and unplanted systems by measuring the effective porosity and hydraulic conductivity of the substrate within different operation periods. Furthermore, the flow pattern of the clogging process in the planted and unplanted wetland systems were evaluated by their hydraulic performance (e.g., mean residence time, short circuiting, volumetric efficiency, number of continuously stirred tank reactors, and hydraulic efficiency factor) in salt tracer experiments. The results showed that the flow conditions would change in different clogging stages, which indicated that plants played different roles related to time and space. In the early clogging stages, plant roots restricted the flow of water, while in the middle and later clogging stages, especially the later stage, growing roots opened new pore spaces in the substrate. The roots played an important role in affecting the hydraulic performance in the upper layer (0-30 cm) where the sand matrix had a larger root volume fraction. Finally, the causes of the controversy over plant roots' effects on clogging were discussed. The results helped further understand the effects of plant roots on hydraulic performance during the clogging process.

Inhibitory effects of capsaicin on hepatic stellate cells and liver fibrosis

Hepatic stellate cells (HSCs) play an important role in the process of liver fibrosis. In this study, we investigated the inhibitory effects of capsaicin on HSCs and liver fibrosis. Cultured HSCs were incubated with various concentrations of capsaicin. Cell proliferation was examined using a cell counting kit. Production of hydrogen peroxide was determined using a 2′,7′-dichlorofluorescin diacetate (DCFH-DA) assay. The mRNA and protein expression of target genes was analyzed by reverse transcription PCR and Western blot analysis, respectively. Cell apoptosis was evaluated by annexin V-FITC and propidium iodide (PI) costaining followed by flow cytometric analysis. A CCl4 rat liver fibrosis model was used to assess in vivo effects of capsaicin by histological examination and measurement of liver fibrosis markers, including hydroxyproline content, serum type III collagen, and hyaluronic acid (HA) levels. Our results show that capsaicin dose-dependently inhibited cell proliferation, suppressed cell activation, and decreased hydrogen peroxide production in cultured HSCs. Capsaicin reduced the mRNA levels of tissue inhibitors of metalloproteinase 1 (TIMP-1) and transforming growth factor-β1 (TGF-β1) in HSCs. Moreover, capsaicin-induced cell apoptosis was associated with increased expression of Bax, cytochrome c (cyt c), and caspase-3, but reduced levels of Bcl-2. The animal studies further revealed that capsaicin efficiently reduced the extent of liver fibrosis, inhibited HSC proliferation, and promoted cell apoptosis. Our findings suggest that capsaicin might inhibit fibrogenesis by inhibiting the activities of HSCs.

[Regulation effect of adipose-derived mesenchymal stem cells on pancreatic cancer cells]

OBJECTIVE

To analyze the effects of adipose tissue-derived stem cells (ADSCs) on the proliferation and invasion of pancreatic cancer (PaCa) cells and the the possible mechanism involved.

METHODS

ADSCs were isolated and co-cultured with PaCa cells. CCK-8 assay was used to detect the proliferation of PaCa cells. An ELISA was used to determine the concentration of stromal cell-derived factor-1 (SDF-1) in the supernatants. The proliferation of PaCa cells by SDF-1 was measured. AMD3100 regulated the co-culture of ADSCs and PaCa. The tumor growth of PaCa cells was assessed after treatment by ADSCs in vivo.

RESULTS

ADSCs can promote the proliferation and invasion of PaCa cells (proliferation: SW1990: 1.535 ± 0.153; PANC-1: 1.370 ± 0.100; the value of control was 1; invasion: SW1990: 47.0 ± 2.6 vs. 28.3 ± 1.3; PANC-1: 40.3 ± 1.8 vs. 24.3 ± 1.3; t = 4.332-9.558, P < 0.05). The expression of SDF-1 was high in ADSCs, but not in PaCa cells (69 ± 5 vs. 0 and 0, F = 389.134, P < 0.01). The promotion of SDF-1 on PaCa cells depends on the concentration. AMD3100 significantly downregulates these growth-promoting effects of ADSCs on PaCa cells. ADSCs significantly promoted the growth of SW1990 in nude mice at the 5(th) week (volume: (1295 ± 102) mm(3) vs. (967 ± 81) mm(3), t = 5.614, P < 0.05) , but not in PANC-1 cell.

CONCLUSION

ADSCs can promote the proliferation and invasion of PaCa cells, which may involve the SDF-1/CXCR4 axis.

The effect of splenic arterial blood flow (SBF) on severity of hypersplenism and analysis of factors associated with SBF

BACKGROUND

This study aims to explore the relationship between spleen arterial blood flow (SBF) with platelet count, spleen index (SPI) and the serum nitric oxide (NO) level of patients with liver cirrhosis and to investigate the role of SBF in the development of hypersplenism.

METHODOLOGY

Platelet count, SPI, SBF and serum NO levels were evaluated in 100 patients with liver cirrhosis caused by hepatitis B with hypersplenism (cirrhosis group) and 30 healthy persons without hypersplenism (control group).

RESULTS

Platelet count in cirrhosis group and control group was 57.0 +/- 25.6 x 109/L and 205.8 +/- 47.4 x 109/L (p = 0.000), SBF was 535.7 +/- 263.7 milmin and 172.2 +/- 66.9 ml/min (p = 0.000), and serum NO level was 98.51 +/- 23.06 micromol/L and 48.43 +/- 19.47 micromol/L (p = 0.000). Linear correlations were made between SBF and platelet count in cirrhosis group (r = -0.573, p = 0.000), SBF and SPI (r = 0.607, p = 0.01), SBF and serum NO level (r = 0.754, p = 0.000). Moreover, serum NO level increased as liver disease aggravated (82.50 +/- 15.04 pmol/L in Child grade A, 94.61 +/- 21.00 micromol/L in grade B and 116.83 +/- 18.03 micromol/L in grade C; grade A versus grade C, p = 0.003).

CONCLUSION

The elevation of SBF may play an important role in the development of hypersplenism and disorders in vasoactive factors such as the serum NO caused by liver cirrhosis may play an important role in the elevation of SBF.

[The pharmacokinetics of SC1001-sodium and SC1001-aminum in human body]

The pharmacokinetics of SC1001-Sodium and SC1001-Aminum in the human body was studied. After 200 mg SC1001-Sodium or SC1001-Aminum by oral administration, plasma concentration-time data were fitted to curves by means of the nonlinear least-square method, employing the program we ourselves compiled. With F-test, comparing gamma 2(1) -value and AIC-value, the linear one compartment open model was available. The mean pharmacokinetic parameters fitted one by one were as follows with the first value given belonging to SC1001-Sodium and the second to SC1001-Aminum: Ka: 0.7248 and 0.5102 h-1; Ke: 0.0597 and 0.1149 h-1; T1/2, a: 1.1437 and 1.8999 h; T1/2, e: 15.7428 and 6.1497 h; AUC: 600.15 and 28.61 micrograms.h/ml; Tm: 4.4798 and 4.3728h.