TGF-β2, catalase activity, H2O2 output and metastatic potential of diverse types of tumour

Virulence attenuation of Theileria annulata-transformed macrophages

Tropical theileriosis is a significant tick-borne disease affecting cattle. For decades an empirical live attenuated vaccine has been the primary method of controlling disease. The vaccine is produced through prolonged culture of Theileria annulata schizont-transformed macrophages, but how loss of virulence occurs remains unclear. Notably attenuated (vaccine) macrophages display dampened dissemination potential compared with their original, virulent counterparts. In addition, parasite schizonts in attenuated macrophages have significantly lost their ability to differentiate into merozoites. This review discusses the changes that occur during long-term passage of T. annulata-transformed bovine macrophages and how they contribute to loss of virulence, defined as heightened dissemination. Finally, we also suggest that a common parasite-dependent pathway is potentially involved in both macrophage dissemination and parasite merogony.

Effects of Albumin-Chlorogenic Acid Nanoparticles on Apoptosis and PI3K/Akt/mTOR Pathway Inhibitory Activity in MDA-MB-435s Cells

In this study, we synthesized, characterized, and explored the anti-microbial and anti-cancer effects of albumin-chlorogenic acid nanoparticles (NPs). Characterization studies with a UV-vis spectrophotometer, FTIR, PL spectrum, TEM, FESEM, XRD, and DLA analysis showed patterns confirming the physio-chemical nature of biogenic nanocomposites. Further, anti-microbial studies using bacterial strains Staphylococcus aureus, Streptococcus pneumonia, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Vibrio cholera, and fungal strain Candida albicans showed significant (p < 0.05) anti-bacterial and anti-fungal activities. Next, we used MDA-MB-435s, a human cell line, to evaluate the anti-cancer effects of albumin-chlorogenic acid NPs. Cytotoxic studies revealed its IC50 concentration at 24 μg/mL after a 24 h treatment of MDA-MB-435s cells. We chose this IC50 dose to analyze albumin-chlorogenic acid NPs anti-cancer effects in vitro. MDA-MB-435s cells exposed to our NPs were studied via AO/EtBr staining, cell cycle analyses via PI staining, the status of whole genomic damage via comet assay, levels of apoptotic cells via annexin V/PI staining, ROS generation via DCFH-DA staining, an assay of antioxidant enzymes catalase, superoxide dismutase, and antioxidant GSH, via ELISA analyses of apoptotic markers caspase-3, 8, 9, Bax, Bcl-2, CytC, and p53, PI3/AKT/mTOR pathway. Our results collectively showed albumin-chlorogenic acid NPs induced apoptosis via p53-dependent and PI3/AKT/mTOR inhibition in MDA-MB-435s cells. Our results denote albumin-chlorogenic acid NPs can be used as an effective candidate for anti-microbial and anti-cancer applications; however, further in vivo confirmatory studies are warranted.

Low-level laser selectively inhibiting colorectal cancer cell metabolic activity and inducing apoptosis for delaying the development of intestinal cancer

Low-level laser irradiation (LLLI) is a novel approach that shows promise for the treatment of colorectal cancer (CRC). However, the molecular mechanisms underlying its biochemical effects and gene expression remain unclear. Here, LLLI (632.8 nm) was used to treat CRC RKO cells and normal small intestinal NCM460 cells. LLLI showed a significant dose- and time-dependent effect on cell viability, in which a single dose of irradiation at 15 J/cm² selectively inhibited the growth of RKO cells but largely unaffected the activity of NCM460 cells. And then, LLLI produced an internal response, effectively reducing the level of H₂O₂ in tumor cells, downregulating the mitochondrial membrane potential, and improving the efficiency of apoptosis in CRC, but no internal response was observed in NCM460 cells under the same conditions. Furthermore, the expression of several important genes in the classical WNT pathway was significantly downregulated, and the pathway was inactivated after LLLI intervention, thereby inhibiting tumor cell growth. Simultaneously, TNF-α was effectively activated to stimulate the caspase family members of the death effector to initiate apoptosis led by the extrinsic pathway. LLLI successfully achieves tumor cell normalization while delivering a potent anticancer effect, expected to be a novel therapeutic modality for CRC.

TGF-β Signaling in Metastatic Colorectal Cancer (mCRC): From Underlying Mechanism to Potential Applications in Clinical Development

Colorectal cancer (CRC) is a serious public health issue, and it has the leading incidence and mortality among malignant tumors worldwide. CRC patients with metastasis in the liver, lung or other distant sites always have poor prognosis. Thus, there is an urgent need to discover the underlying mechanisms of metastatic colorectal cancer (mCRC) and to develop optimal therapy for mCRC. Transforming growth factor-β (TGF-β) signaling plays a significant role in various physiologic and pathologic processes, and aberrant TGF-β signal transduction contributes to mCRC progression. In this review, we summarize the alterations of the TGF-β signaling pathway in mCRC patients, the functional mechanisms of TGF-β signaling, its promotion of epithelial-mesenchymal transition, its facilitation of angiogenesis, its suppression of anti-tumor activity of immune cells in the microenvironment and its contribution to stemness of CRC cells. We also discuss the possible applications of TGF-β signaling in mCRC diagnosis, prognosis and targeted therapies in clinical trials. Hopefully, these research advances in TGF-β signaling in mCRC will improve the development of new strategies that can be combined with molecular targeted therapy, immunotherapy and traditional therapies to achieve better efficacy and benefit mCRC patients in the near future.

TGF-β signaling in the tumor metabolic microenvironment and targeted therapies

Transforming growth factor-β (TGF-β) signaling has a paradoxical role in cancer progression, and it acts as a tumor suppressor in the early stages but a tumor promoter in the late stages of cancer. Once cancer cells are generated, TGF-β signaling is responsible for the orchestration of the immunosuppressive tumor microenvironment (TME) and supports cancer growth, invasion, metastasis, recurrence, and therapy resistance. These progressive behaviors are driven by an “engine” of the metabolic reprogramming in cancer. Recent studies have revealed that TGF-β signaling regulates cancer metabolic reprogramming and is a metabolic driver in the tumor metabolic microenvironment (TMME). Intriguingly, TGF-β ligands act as an “endocrine” cytokine and influence host metabolism. Therefore, having insight into the role of TGF-β signaling in the TMME is instrumental for acknowledging its wide range of effects and designing new cancer treatment strategies. Herein, we try to illustrate the concise definition of TMME based on the published literature. Then, we review the metabolic reprogramming in the TMME and elaborate on the contribution of TGF-β to metabolic rewiring at the cellular (intracellular), tissular (intercellular), and organismal (cancer-host) levels. Furthermore, we propose three potential applications of targeting TGF-β-dependent mechanism reprogramming, paving the way for TGF-β-related antitumor therapy from the perspective of metabolism.

A Photolysis-Assist Molecular Communication for Tumor Biosensing

Molecular communication (MC) is a promising bioinspired paradigm for exchanging molecule information among nanomachines. In this paper, we propose a synchronization-assist photolysis MC system that aims to transmit the biosensing signal of the tumor microenvironment, facilitated by mitigating redundant molecules for improved bit error rate (BER) performance. Benefits from biocompatible MC, biosensors could transmit biosensing signals of the tumor in vivo instead of converting them to electrical signals. Due to diffusion motion’s slow and stochastic nature, intersymbol interference (ISI), resulting from previous symbols’ residual information molecules, inevitably occurs in diffusion-based MC. ISI is one of the challenges in diffusion-based MC, which significantly impacts signal detection. Inspired by on–off keying (OOK) modulation, the proposed modulation implements a switch of molecules and light alternatively. The light emitted is triggered by a synchronization signal, and the photolysis reactions could reduce the redundant molecules. An expression for the relevant channel impulse response (CIR) is derived from a hybrid channel model of diffusion and photolysis reaction. In this paper, we implement the maximum posterior estimation scheme to find the optimal decision threshold and analysis the BER performance in terms of different time intervals of the system. Numerical simulations demonstrate that the proposed method can improve the channel capacity and BER performance. We believe that our work may pave the way for MC application in biosensing.

cAMP-Dependent Signaling Pathways as Potential Targets for Inhibition of Plasmodium falciparum Blood Stages

We review the role of signaling pathways in regulation of the key processes of merozoite egress and red blood cell invasion by Plasmodium falciparum and, in particular, the importance of the second messengers, cAMP and Ca²⁺, and cyclic nucleotide dependent kinases. cAMP-dependent protein kinase (PKA) is comprised of cAMP-binding regulatory, and catalytic subunits. The less well conserved cAMP-binding pockets should make cAMP analogs attractive drug leads, but this approach is compromised by the poor membrane permeability of cyclic nucleotides. We discuss how the conserved nature of ATP-binding pockets makes ATP analogs inherently prone to off-target effects and how ATP analogs and genetic manipulation can be useful research tools to examine this. We suggest that targeting PKA interaction partners as well as substrates, or developing inhibitors based on PKA interaction sites or phosphorylation sites in PKA substrates, may provide viable alternative approaches for the development of anti-malarial drugs. Proximity of PKA to a substrate is necessary for substrate phosphorylation, but the P. falciparum genome encodes few recognizable A-kinase anchor proteins (AKAPs), suggesting the importance of PKA-regulatory subunit myristylation and membrane association in determining substrate preference. We also discuss how Pf14-3-3 assembles a phosphorylation-dependent signaling complex that includes PKA and calcium dependent protein kinase 1 (CDPK1) and how this complex may be critical for merozoite invasion, and a target to block parasite growth. We compare altered phosphorylation levels in intracellular and egressed merozoites to identify potential PKA substrates. Finally, as host PKA may have a critical role in supporting intracellular parasite development, we discuss its role at other stages of the life cycle, as well as in other apicomplexan infections. Throughout our review we propose possible new directions for the therapeutic exploitation of cAMP-PKA-signaling in malaria and other diseases caused by apicomplexan parasites.

Interaction between transforming Theileria parasites and their host bovine leukocytes

Theileria are tick-transmitted parasites that cause often fatal leuko-proliferative diseases in cattle called tropical theileriosis (T. annulata) and East Coast fever (T. parva). However, upon treatment with anti-theilerial drug-transformed leukocytes die of apoptosis indicating that Theileria-induced transformation is reversible making infected leukocytes a powerful example of how intracellular parasites interact with their hosts. Theileria-transformed leukocytes disseminate throughout infected cattle causing a cancer-like disease and here, we discuss how cytokines, noncoding RNAs and oncometabolites can contribute to the transformed phenotype and disease pathology.