Pinellia pedatisecta agglutinin interacts with the methylosome and induces cancer cell death

Lectins of the Araceae family: Insights, distinctions, and future avenues-A three-decade investigation

The Araceae family boasts >3000 species of flowering plants that thrive across the tropics. Among the focal points of study within this family are lectins, proteins with affinity for binding carbohydrates. This review endeavors to gather data gleaned from numerous studies conducted over the past three decades on lectins extracted from Araceae plants. Our examination spans their extraction and purification methods, their specific interactions with carbohydrates, their molecular structures, and various physicochemical characteristics. Furthermore, we investigated the biological activities of these lectins and investigated the outcomes of cloning their genes. Despite their apparent similarities, these lectins exhibit notable distinctions, particularly regarding their unique preferences in interacting with erythrocytes from animals and humans, their sugar affinities, the critical amino acids for their functionality, the molecular weights of their subunits and their respective topologies, and ultimately, their dimerization and 3D β-prism-II structure, which reportedly diverge from those observed in other GNA-related lectins. These discrepancies not only deepen our understanding of monocot lectins but also render these proteins inherently captivating. This review marks the inaugural attempt at consolidating almost all published reports on lectins from the Araceae family, with the aim of furnishing glycobiology scientists with essential insights into potential laboratory challenges, the characteristics of these lectins, and avenues for future research.

The efficacy and safety of Xiao-Ban-Xia-Tang in the treatment of chemotherapy-induced nausea and vomiting: A systematic review and meta-analysis

Background

Chemotherapy-induced nausea and vomiting (CINV) is one of the most frequent and critical side effects due to chemotherapeutics. In China, Xiao-Ban-Xia-Tang (XBXT) has already been applied extensively to prevent and treat CINV. However, there is limited testimony on the effectiveness and safety of this purpose, and there was no correlative systematic review. The aim of this review was to systematically evaluate the effectiveness and safety of XBXT in preventing and treating CINV.

Methods

The systematic search was conducted in eight databases to acquire randomized controlled trials (RCTs) that appraised the effect of XBXT in treating CINV. The vomiting and nausea relief efficiency, eating efficiency, quality of life, and adverse reactions were explored for efficacy assessment. Bias risk was rated by manipulating the Cochrane risk of bias tool 2.0 (RoB 2). The retrieved investigations were analyzed by utilizing ReviewManager 5.4 and Stata 17.0. The quality of evidence was evaluated adopting the GRADE tool.

Results

A total of 16 clinical RCTs of XBXT in the treatment of CINV were incorporated into the investigation, with a total of 1246 participants. The meta-analysis showed that compared with conventional antiemetic drugs, XBXT and antiemetics improved the vomiting relief efficiency (RR 1.35, 95% confidence interval: 1.25-1.46, p < 0.00001), nausea relief efficiency (N = 367, RR 1.23, 95% CI: 1.09-1.38, p < 0.00001), and quality of life (RR = 1.37, 95% CI: 1.14-1.65, p = 0.0009) and reduced the adverse events (N = 370, RR 0.53, 95% CI: 0.29-0.96, p = 0.04). XBXT and DARAs raised eating efficiency compared with DARAs (N = 208, RR 1.30, 95% CI: 1.07-1.57, p = 0.007). The data existed as statistically significant, and the publication bias was identified as relatively low from the funnel plot and trim and fill analysis. In addition, sensitivity analysis demonstrated robust outcomes. The quality of evidence for each outcome ranged from moderate to high.

Conclusion

There is some encouraging evidence that XBXT and antiemetics had better therapeutic effects and safety in treating CINV than antiemetic drugs alone. The quality assessment and low publication bias indicated that the overall criterion was scientific. Better research is required to verify the evidence designed with large-scale RCTs and rigorous methods.

Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=281046.

Lignocellulosic biomass-based glycoconjugates for diverse biotechnological applications

Glycoconjugates are the ubiquitous components of mammalian cells, mainly synthesized by covalent bonds of carbohydrates to other biomolecules such as proteins and lipids, with a wide range of potential applications in novel vaccines, therapeutic peptides and antibodies (Ab). Considering the emerging developments in glycoscience, renewable production of glycoconjugates is of importance and lignocellulosic biomass (LCB) is a potential source of carbohydrates to produce synthetic glycoconjugates in a sustainable pathway. In this review, recent advances in glycobiology aiming on glycoconjugates production is presented together with the recent and cutting-edge advances in the therapeutic properties and application of glycoconjugates, including therapeutic glycoproteins, glycosaminoglycans (GAGs), and nutraceuticals, emphasizing the integral role of glycosylation in their function and efficacy. Special emphasis is given towards the potential exploration of carbon neutral feedstocks, in which LCB has an emerging role. Techniques for extraction and recovery of mono- and oligosaccharides from LCB are critically discussed and influence of the heterogeneous nature of the feedstocks and different methods for recovery of these sugars in the development of the customized glycoconjugates is explored. Although reports on the use of LCB for the production of glycoconjugates are scarce, this review sets clear that the potential of LCB as a source for the production of valuable glycoconjugates cannot be underestimated and encourages that future research should focus on refining the existing methodologies and exploring new approaches to fully realize the potential of LCB in glycoconjugate production.

Pinellia genus: A systematic review of active ingredients, pharmacological effects and action mechanism, toxicological evaluation, and multi-omics application

The dried tuber of Pinellia ternata (Thunb.) Breit, Pinelliae Rhizoma (PR, also named 'Banxia' in Chinese), is widely used in traditional medicine. This review aims to provide detail summary of active ingredients, pharmacological effects, toxic ingredients, detoxification strategies, and omic researches, etc. Pharmacological ingredients from PR are mainly classified into six categories: alkaloids, amino acids, polysaccharides, phenylpropanoids, essential oils, and glucocerebrosides. Diversity of chemical composition determines the broad-spectrum efficacy and gives a foundation for the comprehensive utilization of P. ternata germplasm resources. The pharmacological compounds are involved in inhibition of cancer cells by targeting various pathways, including activation of immune system, inhibition of proliferation and cycle, induction of apoptosis, and inhibition of angiogenesis. The pharmacological components of PR act on nervous system by targeting neurotransmitters, activating immune system, decreasing apoptosis, and increasing redox system. Lectins, one major class of the toxic ingredients extracted from raw PR, possess significant toxic effects on human cells. Inflammatory factors, cytochrome P450 proteins (CYP) family enzymes, mammalian target of rapamycin (mTOR) signaling factors, transforming growth factor-β (TGF-β) signaling factors, and nervous system, are considered to be the target sites of lectins. Recently, omic analysis is widely applied in Pinellia genus studies. Plastome genome-based molecular markers are deeply used for identifying and resolving phylogeny of Pinellia genus plants. Various omic works revealed and functional identified a series of environmental stress responsive factors and active component biosynthesis-related genes. Our review summarizes the recent progress in active and toxic ingredient evaluation, pharmacological effects, detoxification strategies, and functional gene identification and accelerates efficient utilization of this traditional herb.

Plant lectin: A promising future anti-tumor drug

Since the early discovery of plant lectins at the end of the 19th century, and the finding that they could agglutinate erythrocytes and precipitate glycans from their solutions, many applications and biological roles have been described for these proteins. Later, the observed erythrocytes clumping features were attributed to the lectin-cell surface glycoconjugates recognition. Neoplastic transformation leads to various cellular alterations which impact the growth of the cell and its persistence, among which is the mutation in the outer surface glycosylation signatures. Quite a few lectins have been found to act as excellent biomarkers for cancer diagnosis while some were presented with antiproliferative activity that initiated by lectin binding to the respective glycocalyx receptors. These properties are blocked by the hapten sugar that is competing for the lectin affinity binding site. In vitro investigations of lectin-cancer cell's glycocalyx interactions lead to a series of immunological reactions that result in autophagy or apoptosis of the transformed cells. Mistletoe lectin, an agglutinin purified from the European Viscum album is the first plant lectin employed in the treatment of cancer to enter into the clinical trial phases. The entrapment of lectin in nanoparticles besides other techniques to promote bioavailability and stability have also been recently studied. This review summarizes our up-to-date understanding of the future applications of plant lectins in cancer prognosis and diagnosis. With the provision of many examples of lectins that exhibit anti-neoplastic properties.

A lipid-soluble extract of Pinellia pedatisecta Schott orchestrates intratumoral dendritic cell-driven immune activation through SOCS1 signaling in cervical cancer

ETHNOPHARMACOLOGICAL RELEVANCE

Pinellia pedatisecta Schott extract (PE) is generated from Pinellia pedatisecta Schott, a traditional Chinese medicinal plant. PE suppresses cervical tumor growth and exhibits effects on dendritic cells (DCs) that lead to modulation of antitumor CD4⁺ and CD8⁺ responses.

AIMS

To explore the underlying mechanisms by which PE modulates tumor-associated dendritic cell (TADC) activation and function.

METHODS

DCs and TADCs were generated from murine bone marrow and exposed to PE solutions at different doses, as well as to repeated doses separated at different time intervals. Quantitative PCR, Western blot analysis, flow cytometry, and gene silencing were used to analyze the modulatory effects of PE on the SOCS1/JAK2/STAT pathways. Furthermore, we separated human cervical tumor-infiltrated DCs (TIDCs) and conducted an ex-vivo stimulation model to observe the effect of PE. For phenotypic analysis of cultured DCs and ex vivo human specimens, we used flow cytometry to detect the molecular markers associated with cell function.

RESULTS

In cultured TADCs and human cervical TIDCs, maturation- and functional markers (MHCII, CD80, CD83, CD86, and IL-12) were downregulated, whereas SOCS1 was upregulated. PE enhanced the expression of CD80, CD86, and IL-12 in cervical TIDCs, which induced increased expression of CD107a, GZMB, and perforin in CTLs, and furthermore induced apoptosis in a larger number of tumor cells. In cultured TADCs, PE downregulated SOCS1 expression and activated the phosphorylation of JAK2, STAT1, STAT4, and STAT5 in both dose- and time-dependent manners. The effects of PE upregulating MHCII, CD80, CD86, IL-12 on TADCs were blocked after SOCS1 silencing.

CONCLUSIONS

In this study, PE restored the impaired function of cervical TIDCs, thereby eliciting further antitumor CTL responses. The effects of PE on TADCs were mediated through inhibition of SOCS1 and activation of downstream JAK2-STAT1/STAT4/STAT5 pathways. PE may be a potent and effective immunomodulatory drug for antitumor treatment via the blockade of SOCS1 signaling in DCs.

Pinellia ternata (Thunb.) Breit: A review of its germplasm resources, genetic diversity and active components

ETHNOPHARMACOLOGICAL RELEVANCE

The medicinal plant Pinellia ternata has been widely used in China, Korea, and Japan and has been demonstrated to be highly effective for treating cough, vomiting, infection, and inflammatory diseases. Modern pharmacological investigations have demonstrated its multiple activities, such as antitussive, expectorant, antiemetic, antitumor, antibacterial, and sedative-hypnotic activities.

AIM OF THE REVIEW

This review aims to summarize the information about the biological traits, genetic diversity, active components, and continuous cropping obstacle of P. ternata in order to improve its use.

MATERIALS AND METHODS

In this review, the relevant literature was gathered by using Pinellia ternata, genetic diversity, active components, and continuous cropping obstacle as the keywords from Google Scholar, PubMed, Springer Link, the Wiley online library, SciFinder, SCOPUS, Baidu Scholar, China national knowledge infrastructure (CNKI), and WANFANF DATA (up to April 2020).

RESULTS

P. ternata is the most widely used herb in the Pinellia genus to treat several diseases. The genetic diversity of P. ternata has been extensively studied, and its high genetic diversity level in China has been demonstrated. Modern pharmacological research has indicated that amino acids, alkaloids, and polysaccharides are the main active components supporting P. ternata's medicinal effects. However, an efficient method for determining its active components is still unavailable. The method used to evaluate Pinelliae Rhizoma (PR) quality standards should be further optimized. The continuous cropping obstacle has a significant effect on the quantity and quality of P. ternata. The underlying mechanism of the continuous cropping obstacle needs to be further explored.

CONCLUSIONS

P. ternata has emerged as a valuable source of traditional medicine. Some uses of P. ternata in medicine have been validated by pharmacological investigations. However, a more efficient analytical method should be established to evaluate the quality of PR based on multiple quality markers. Furthermore, high-performance liquid chromatography (HPLC) and DNA barcoding should be introduced to identify the authenticity of PR. In addition, the genes involved in the metabolic synthesis pathways of the main active components, population genetic relationships, the quality control of processed PR, and the continuous cropping obstacle need to be further elucidated. We hope this review will allow for better utilization of this valuable herb.

A lipid-soluble extract of Pinellia pedatisecta Schott enhances antitumor T cell responses by restoring tumor-associated dendritic cell activation and maturation

ETHNOPHARMACOLOGICAL RELEVANCE

Pinellia pedatisecta Schott (PPS)is a traditional Chinese medicine functioning as reducing swelling and drying dampness. Pinellia pedatisecta Schott extract (PE) has been confirmed to suppress cervical tumor growth and modulate the antitumor CD4⁺T helper immunity towards Th1.

AIMS

To explore the roles of PE in modulating tumor-associated dendritic cell (TADC) activation and function.

METHODS

For in vivo studies, HPV⁺TC-1 mouse tumor models were conducted and treated with PE for 3 weeks (10 mg/kg/d or 20 mg/kg/day). The immune profiles of spleen, tumor-draining lymph nodes (TDLNs), tumor and serum were analyzed by flow cytometry and multiplexed bead-based immunoassay. For in vitro studies, TADCs were generated by tumor-conditioned medium and treated with PE solution. The maturation and function of TADCs were evaluated by flow cytometry, ELISA, mixed lymphocyte reaction (MLR) and cytotoxic T lymphocyte (CTL) assay. Furthermore, the effect of PE on SOCS1 pathway was examined by western blotting and real time PCR.

RESULTS

PE upregulated the expression of major histocompatibility complex class II (MHCII) and costimulatory molecules CD80 and CD86 on TADCs and promoted IL-12 secretion from TADCs. In addition, PE-treated TADCs promoted the proliferation of CD4⁺ and CD8⁺ T cells and induced the differentiation of IFN-γ⁺CD4⁺ and GZMB⁺CD8⁺ T cells. PE-treated TADCs also elicited a more powerful antigen-specific cytotoxic T lymphocyte (CTL) response. Furthermore, PE treatment in vivo enhanced the proliferation, activated the functional ability (increased Ki67, CD137, GZMB or IFN-γ, TNF-α expression) and reversed the exhaustion (impaired CD95 or PD-1 expression) of antitumor T cells. Mechanistically, PE inhibited SOCS1-restrained JAK2 activation in TADCs.

CONCLUSIONS

PE efficiently restored the immature status of TADCs and enhanced their function as antigen-presenting cells to further elicit antitumor Th1 and CTL responses, suggesting that PE may be a potential immunomodulatory drug for cancer treatment.

Oncolytic Vaccinia Virus Expressing Aphrocallistes vastus Lectin as a Cancer Therapeutic Agent

Lectins display a variety of biological functions including insecticidal, antimicrobial, as well as antitumor activities. In this report, a gene encoding Aphrocallistes vastus lectin (AVL), a C-type lectin, was inserted into an oncolytic vaccinia virus vector (oncoVV) to form a recombinant virus oncoVV-AVL, which showed significant in vitro antiproliferative activity in a variety of cancer cell lines. Further investigations revealed that oncoVV-AVL replicated faster than oncoVV significantly in cancer cells. Intracellular signaling elements including NF-κB2, NIK, as well as ERK were determined to be altered by oncoVV-AVL. Virus replication upregulated by AVL was completely dependent on ERK activity. Furthermore, in vivo studies showed that oncoVV-AVL elicited significant antitumor effect in colorectal cancer and liver cancer mouse models. Our study might provide insights into a novel way of the utilization of marine lectin AVL in oncolytic viral therapies.

Plant protein-based hydrophobic fine and ultrafine carrier particles in drug delivery systems

For thousands of years, plants and their products have been used as the mainstay of medicinal therapy. In recent years, besides attempts to isolate the active ingredients of medicinal plants, other new applications of plant products, such as their use to prepare drug delivery vehicles, have been discovered. Nanobiotechnology is a branch of pharmacology that can provide new approaches for drug delivery by the preparation of biocompatible carrier nanoparticles (NPs). In this article, we review recent studies with four important plant proteins that have been used as carriers for targeted delivery of drugs and genes. Zein is a water-insoluble protein from maize; Gliadin is a 70% alcohol-soluble protein from wheat and corn; legumin is a casein-like protein from leguminous seeds such as peas; lectins are glycoproteins naturally occurring in many plants that recognize specific carbohydrate residues. NPs formed from these proteins show good biocompatibility, possess the ability to enhance solubility, and provide sustained release of drugs and reduce their toxicity and side effects. The effects of preparation methods on the size and loading capacity of these NPs are also described in this review.

Ulva pertusa lectin 1 delivery through adenovirus vector affects multiple signaling pathways in cancer cells

Ulva pertusa lectin 1 (UPL1) is a N-acetyl-D-glucosamine (GlcNAc) binding lectin in marine green alga Ulva pertusa. Exogenous UPL1 colocalized with protein arginine methyltransferase 5 (PRMT5), methylosome protein 50 (MEP50), β-actin and β-tubulin, indicating the interaction of UPL1 with the methylosome and cytoskeleton. UPL1 delivery through adenovirus vector (Ad-UPL1) dramatically induced extracellularly regulated protein kinases 1/2 (ERK1/2) phosphorylation in liver cancer cell lines BEL-7404 and Huh7. Signaling pathways including p38 mitogen-activated protein kinase (MAPK), and Akt were also affected by Ad-UPL1 in a cell type dependent manner. MEK1/2 inhibitor U0126, as well as to a lesser extent p38 MAPK inhibitor SB203580 and phosphoinositide 3-kinase (PI3K) inhibitor LY294002, completely eliminated a higher molecular weight isoform of β-tubulin induced by Ad-UPL1, and significantly enhanced the cytotoxicity of Ad-UPL1 in Huh7 cells, suggesting that the inhibition of MEK1/2, p38 MAPK, and PI3K enhanced antiproliferative effect of Ad-UPL1 possibly through regulating the modification of β-tubulin. Ad-UPL1 completely inhibited the expression of autophagy-related factor Beclin1, but induced LC3-II expression in Huh7 cells. In addition, Ad-UPL1 significantly enhanced starvation induced survival suppression in Huh7 cells. Our data elucidated intracellular signaling pathways affected by exogenous UPL1, and may provide insights into a novel way of UPL1 delivery through adenovirus vectors combined with survival signaling inhibitors for cancer treatment.

Marine Lectins DlFBL and HddSBL Fused with Soluble Coxsackie-Adenovirus Receptor Facilitate Adenovirus Infection in Cancer Cells BUT Have Different Effects on Cell Survival

Cancer development and progression are usually associated with glycosylation change, providing prognostic and diagnostic biomarkers, as well as therapeutic targets, for various cancers. In this work, Dicentrarchus labrax fucose binding lectin (DlFBL) and Haliotis discus discus sialic acid binding lectin (HddSBL) were genetically fused with soluble coxsackie-adenovirus receptor (sCAR), and produced through a bacterial expression system. Results showed that recombinant sCAR-DlFBL not only facilitated adenovirus Ad-EGFP infection in K562/ADR and U87MG cells, but also enhanced the cytotoxicity of adenovirus harboring gene encoding Pinellia pedatisecta agglutinin (PPA) or DlFBL (Ad-PPA or Ad-DlFBL) on U87MG cells through inducing apoptosis. Recombinant sCAR-HddSBL facilitated Ad-EGFP infection, but dramatically counteracted the cytotoxicity of both Ad-PPA and Ad-DlFBL in U87MG cells. Further analysis revealed that sCAR-HddSBL, but not sCAR-DlFBL, significantly upregulated transcription factor E2F1 levels in U87MG cells, which might be responsible for the adverse effect of sCAR-HddSBL on Ad-PPA and Ad-DlFBL. Taken together, our data suggested that sCAR-DlFBL could be further developed to redirect therapeutic adenoviruses to infect cancer cells such as U87MG, and the sCAR-lectin fusion proteins for adenoviral retargeting should be carefully examined for possible survival signaling induced by lectins, such as HddSBL.

Pharmacodynamic study on insomnia-curing effects of Shuangxia Decoction in Drosophila melanogaster

The present study aimed to establish a pharmacodynamic method using the pySolo software to explore the influence of freeze-dried powders of Shuangxia Decoction (SXD) on the sleep of normal Drosophila melanogaster and the Drosophila melanogaster whose sleep was divested by light. The dose-effect and the time-effect relationships of SXD on sleep were examined. The effect-onset concentration of SXD was 0.25%, the plateau appeared at the concentration of 2.5% and the total sleep time showed a downtrend when the concentration was greater than 2.5%. The sleep time was the longest on the fourth day after SXD was given. The fruit fly sleep deprivation model was repeated by light stimulation at night. The middle dosage group (2.5%) had the best insomnia-curing effect. In conclusion, using the pySolo software, an approach for the pharmacodynamics study was established with Drosophila melanogaster as a model organism to determine the insomnia-curing effects of the traditional Chinese medicine (TCM). Our results demonstrated the reliability of this method. The freeze-dried powders of SXD could effectively improve the sleep quality of Drosophila melanogaster.

Adenovirus carrying gene encoding Haliotis discus discus sialic acid binding lectin induces cancer cell apoptosis

Lectins exist widely in marine bioresources such as bacteria, algae, invertebrate animals and fishes. Some purified marine lectins have been found to elicit cytotoxicity to cancer cells. However, there are few reports describing the cytotoxic effect of marine lectins on cancer cells through virus-mediated gene delivery. We show here that a replication-deficient adenovirus-carrying gene encoding Haliotis discus discus sialic acid binding lectin (Ad.FLAG-HddSBL) suppressed cancer cell proliferation by inducing apoptosis, as compared to the control virus Ad.FLAG. A down-regulated level of anti-apoptosis factor Bcl-2 was suggested to be responsible for the apoptosis induced by Ad.FLAG-HddSBL infection. Further subcellular localization studies revealed that HddSBL distributed in cell membrane, ER, and the nucleus, but not in mitochondria and Golgi apparatus. In contrast, a previously reported mannose-binding lectin Pinellia pedatisecta agglutinin entered the nucleus as well, but did not distribute in inner membrane systems, suggesting differed intracellular sialylation and mannosylation, which may provide different targets for lectin binding. Further cancer-specific controlling of HddSBL expression and animal studies may help to provide insights into a novel way of anti-cancer marine lectin gene therapy. Lectins may provide a reservoir of anti-cancer genes.

Pinellia pedatisecta agglutinin-based lectin blot analysis distinguishes between glycosylation patterns in various cancer cell lines

The analysis of altered glycosylation patterns may provide biomarkers for various types of cancer. The present study developed a Pinellia pedatisecta agglutinin (PPA)-based lectin blot analysis technique, which was used to analyze the glycosylation patterns in various types of cancer cells. Results showed that a typical band located between 47 and 85 kDa was obtained in the HL60 leukemia cells, whereas three typical bands located between 20 and 47 kDa were observed in the Kasumi-1 leukemia cells. For the PLC, BEL-7404, Huh7 and H1299 solid tumor cell lines, different band patterns were detected, with bands typically located between 55 and 100 kDa. The findings of the present study show that PPA-based lectin blot analysis is capable of distinguishing between glycosylation patterns in leukemia and solid tumor cell lines. The glycofiles detected using PPA-based lectin blot analysis may provide a ‘glycosylation fingerprint’ for a variety of cancer cells, which may be valuable for cancer prognosis and diagnosis.

Rhizoma Pinelliae trypsin inhibitor separation, purification and inhibitory activity on the proliferation of BGC-823 gastric adenocarcinoma cells

The aim of this study was to isolate and purify Rhizoma Pinelliae trypsin inhibitor (RPTI), determine its N-terminal amino acid sequence and evaluate its inhibitory effect on the proliferation of poorly differentiated BGC-823 human gastric adenocarcinoma cells. RPTI was separated and purified from a 40% (NH₄)₂SO₄ precipitate of crude protein extract of Pinellia ternata tuber using affinity chromatography with trypsin as the ligand. The N-terminal amino acid sequence of RPTI was determined using the Edman degradation method. The inhibitory effect of RPTI on BGC-823 cell proliferation was detected in vitro using the MTT method and in vivo in tumour-bearing mice. The purified RPTI showed a single band under SDS-PAGE, its molecular weight was 14 kDa and its N-terminal amino acid sequence was DPVVDG. RPTI inhibited trypsin activity, with an inhibition ratio of 1:6.78 (mass). RPTI significantly inhibited the proliferation of BGC-823 cells in vitro. The IC₅₀ of RPTI was 16.96 μg/ml within 48 h after treatment and 9.61 μg/ml within 72 h after treatment. Subcutaneous injection of RPTI around the tumour significantly inhibited BGC-823 tumour growth in mice. The tumour inhibitory effect was concentration- and dose-dependent. RPTI did not significantly influence the spleen coefficient of the mice. In conclusion, RPTI is a serine proteinase inhibitor with antitumour activity.

Exogenous expression of marine lectins DlFBL and SpRBL induces cancer cell apoptosis possibly through PRMT5-E2F-1 pathway

Lectins are widely existed in marine bioresources, and some purified marine lectins were found toxic to cancer cells. In this report, genes encoding Dicentrarchus labrax fucose-binding lectin (DlFBL) and Strongylocentrotus purpuratus rhamnose-binding lectin (SpRBL) were inserted into an adenovirus vector to form Ad.FLAG-DlFBL and Ad.FLAG-SpRBL, which elicited significant in vitro suppressive effect on a variety of cancer cells. Anti-apoptosis factors Bcl-2 and XIAP were determined to be downregulated by Ad.FLAG-DlFBL and Ad.FLAG-SpRBL. Subcellular localization studies showed that DlFBL but not SpRBL widely distributed in membrane systems. Both DlFBL and SpRBL were shown associated with protein arginine methyltransferase 5 (PRMT5), and PRMT5-E2F-1 pathway was suggested to be responsible for the DlFBL and SpRBL induced apoptosis. Further investigations revealed that PRMT5 acted as a common binding target for various exogenous lectin and non-lectin proteins, suggesting a role of PRMT5 as a barrier for foreign gene invasion. The cellular response to exogenous lectins may provide insights into a novel way for cancer gene therapy.

CD123 targeting oncolytic adenoviruses suppress acute myeloid leukemia cell proliferation in vitro and in vivo

We report here a novel strategy to redirect oncolytic adenoviruses to CD123 by carry a soluble coxsackie-adenovirus receptor (sCAR)-IL3 expression cassette in the viral genome to form Ad.IL3, which sustainably infected acute myeloid leukemia (AML) cells through CD123. Ad.IL3 was further engineered to harbor gene encoding manganese superoxide dismutase (MnSOD) or mannose-binding plant lectin Pinellia pedatisecta agglutinin (PPA), forming Ad.IL3-MnSOD and Ad.IL3-PPA. As compared with Ad.IL3 or Ad.sp-E1A control, Ad.IL3-MnSOD and Ad.IL3-PPA significantly suppressed in vitro proliferation of HL60 and KG-1 cells. Elevated apoptosis was detected in HL60 and KG-1 cells treated with either Ad.IL3-MnSOD or Ad.IL3-PPA. The caspase-9–caspase-7 pathway was determined to be activated by Ad.IL3-MnSOD as well as by Ad.IL3-PPA in HL60 cells. In an HL60/Luc xenograft nonobese diabetic/severe-combined immunodeficiency mice model, Ad.IL3-MnSOD and Ad.IL3-PPA suppressed cancer cell growth as compared with Ad.IL3. A significant difference of cancer cell burden was detected between Ad.IL3 and Ad.IL3-PPA groups at day 9 after treatment. Furthermore, Ad.IL3-MnSOD significantly prolonged mouse survival as compared with Ad.sp-E1A. These findings demonstrated that Ad.IL3-gene could serve as a novel agent for AML therapy. Harboring sCAR-ligand expression cassette in the viral genome may provide a universal method to redirect oncolytic adenoviruses to various membrane receptors on cancer cells resisting serotype 5 adenovirus infection.

The ethnobotanical, phytochemical and pharmacological profile of the genus Pinellia

The genus Pinellia (Araceae), consisting of nine species, is mainly distributed in Eastern Asia. In traditional medicine, some Pinellia species have long been used for the treatment of various ailments, such as cough, vomiting, inflammation, epilepsy, cervical cancer and traumatic injury. Pharmacological studies revealed that Pinellia species possess a wide range of biological activities including cytotoxic, anti-tumor, antiemetic, insecticidal, antitussive, antimicrobial and anticonvulsant activities. However, some species also showed significant toxicity such as reproductive toxicity, mucosal irritation and hepatotoxicity. Most of these bioactivities and toxicity can be explained by the presence of various alkaloids and lectins. This review summarizes the ethnopharmacological uses, phytochemical constituents, pharmacological activities and toxicity of Pinellia species.

Cellular localization of protein arginine methyltransferase-5 correlates with grade of lung tumors

Background

Protein arginine methyltransferase-5 (PRMT5) is a chromatin-modifying enzyme capable of methylating histone and non-histone proteins, and is involved in a wide range of cellular processes that range from transcriptional regulation to organelle biosynthesis. As such, its overexpression has been linked to tumor suppressor gene silencing, enhanced tumor cell growth and survival.

Material and methods

Quantitative real-time polymerase chain reaction, Western immunoblot and immunohistochemistry were used to characterize PRMT5 expression in lung cancer cell lines and human tumors. Clinicopathological findings of tissue microarray based samples from 229 patients with non-small cell lung carcinomas (NSCLC) and 133 cases with pulmonary neuroendocrine tumors (NET) were analyzed with regard to nuclear and cytoplasmic PRMT5 expression.

Results

There was statistically significant difference in PRMT5 messenger RNA expression between tumors and nonneoplastic lung tissues. Immunoblot experiments showed abundant expression of PRMT5 and its symmetric methylation mark H4R3 in lung carcinoma but not in non-neoplastic human pulmonary alveolar and bronchial epithelial cell lines. More than two thirds of lung tumors expressed PRMT5. High levels of cytoplasmic PRMT5 were detected in 20.5% of NSCLC and in 16.5% of NET; high levels of nuclear PRMT5 were detected in 38.0% of NSCLC and 24.0% of NET. Cytoplasmic PRMT5 was associated with high grade in both NSCLC and pulmonary NET while nuclear PRMT5 was more frequent in carcinoid tumors (p < 0.05).

Conclusion

The observed findings support the role of PRMT5 in lung tumorigenesis and reflect its functional dichotomy in cellular compartments.

Virtual slide

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1611895162102528

Pinellia pedatisecta agglutinin targets drug resistant K562/ADR leukemia cells through binding with sarcolemmal membrane associated protein and enhancing macrophage phagocytosis

Pinelliapedatisecta agglutinin (PPA) has previously been used in labeling fractions of myeloid leukemia cells in our laboratory. We report here that a bacterial expressed recombinant PPA domain b tagged with soluble coxsackie and adenovirus receptor (sCAR-PPAb) preferentially recognized drug resistant cancer cells K562/ADR and H460/5Fu, as compared to their parental cell lines. Pretreatment of K562/ADR cells with sCAR-PPAb significantly enhanced phagocytosis of K562/ADR by macrophages in vivo. Meanwhile, in a K562/ADR xenograft model, intratumoral injection of sCAR-PPAb induced macrophage infiltration and phagocytosis. Furthermore, immunoprecipitation, mass spectrometry and Western blot identified the membrane target of PPA on K562/ADR as sarcolemmal membrane associated protein (SLMAP). An antibody against SLMAP significantly promoted the phagocytosis of K562/ADR by macrophages in vitro. These findings suggest that PPA not only could be developed into a novel agent that can detect drug resistant cancer cells and predict chemotherapy outcome, but also it has potential value in immunotherapy against drug resistant cancer cells through inducing the tumoricidal activity of macrophages.