Bone mesenchymal stem cells promote gastric cancer progression through TGF-β1/Smad2 positive feedback loop

The dual role of autophagy in cancer stem cells: implications for tumor progression and therapy resistance

Cancer stem cells (CSCs) constitute a small yet crucial subgroup in tumors, known for their capacity to self-renew, differentiate, and promote tumor growth, metastasis, and resistance to therapy. These characteristics position CSCs as significant factors in tumor recurrence and unfavorable clinical results, emphasizing their role as targets for therapy. Autophagy, an evolutionarily preserved cellular mechanism for degradation and recycling, has a complex function in cancer by aiding cell survival during stress and preserving balance by eliminating damaged organelles and proteins. Although autophagy can hinder tumor growth by reducing genomic instability, it also aids tumor advancement, particularly in harsh microenvironments, highlighting its dual characteristics. Recent research has highlighted the complex interactions between autophagy and CSCs, showing that autophagy governs CSC maintenance, boosts survival, and aids in resistance to chemotherapy and radiotherapy. On the other hand, in specific situations, autophagy may restrict CSC growth by increasing differentiation or inducing cell death. These intricate interactions offer both obstacles and possibilities for therapeutic intervention. Pharmacological modulation of autophagy, via inhibitors like chloroquine or by enhancing autophagy when advantageous, has demonstrated potential in making CSCs more responsive to standard treatments. Nonetheless, applying these strategies in clinical settings necessitates a better understanding of context-dependent autophagy dynamics and the discovery of dependable biomarkers indicating autophagic activity in CSCs. Progressing in this area might unveil novel, accurate strategies to tackle therapy resistance, lessen tumor recurrence, and ultimately enhance patient outcomes.

The combination of paeoniflorin and metformin synergistically inhibits the progression of liver fibrosis in mice

Liver fibrosis is a pathological process that endangers human health, for which effective treatments remain elusive to date. Paeoniflorin (PAE), a pineane-type monoter penoid compound from the traditional Chinese medicine PaeoniaeRubra Radix, and metformin (MET), an oral biguanide hypoglycemic agent, both demonstrate anti-inflammatory and hepatoprotective effects. In current work, we first discovered that the combined treatment of PAE and MET synergistically inhibited the progression of liver fibrosis in two different animal models: therapeutic and preventive. This therapeutic effect is evidenced by a reduction in the expression levels of liver fibrosis markers and an improvement in histopathological characteristics. Mechanistic exploration further revealed that this combination therapy downregulated the expression of TGF-β1 and p-Smad2, while upregulating Smad7 expression in both models. Importantly, we also found that this combinatorial approach significantly reduced hepatotoxicity and nephrotoxicity in both models. Our findings suggest an effective combination therapy for liver fibrosis and provide the possibility of therapeutic improvement for patients with liver fibrosis.

Mesenchymal stem cells and their potential therapeutic benefits and challenges in the treatment and pathogenesis of gastric cancer

Mesenchymal stem/stromal cells (MSCs) are acknowledged for their remarkable ability to undergo differentiation into various cell types. In addition, they exhibit anti-tumor characteristics, prompting endeavors to modify MSCs for employment in cancer therapies. On the contrary, it is imperative to recognize that MSCs have been extensively linked to pathways that facilitate the advancement of tumors. Numerous research studies have sought to modify MSCs for clinical application; however, the outcomes have been ambiguous, potentially due to the heterogeneity of MSC populations. Furthermore, the conflicting roles of MSCs in suppressing and promoting tumor growth present a challenge to the appropriateness of their use in anti-cancer therapies. Currently, there exists a lack of comprehensive comprehension concerning the anti-tumor and pro-tumor characteristics of MSCs for gastric cancer (GC). This article discusses the influence of MSCs on GC, the underlying mechanisms, the origins of MSCs, and their effects. This review article also elucidates how MSCs exhibit dual characteristics of promoting and inhibiting tumor growth. Hence, it is of utmost importance that clinical inquiries aimed at utilizing MSCs as a therapeutic intervention for cancer consider the potentiality of MSCs to accelerate the progression of GC. It is crucial to exercise caution throughout the process of developing MSC-based cellular therapies to enhance their anti-cancer attributes while simultaneously eliminating their tumor-promoting impacts.

Nanotechnology and bioengineering approaches to improve the potency of mesenchymal stem cell as an off-the-shelf versatile tumor delivery vehicle

Targeting actionable mutations in oncogene-driven cancers and the evolution of immuno-oncology are the two prominent revolutions that have influenced cancer treatment paradigms and caused the emergence of precision oncology. However, intertumoral and intratumoral heterogeneity are the main challenges in both fields of precision cancer treatment. In other words, finding a universal marker or pathway in patients suffering from a particular type of cancer is challenging. Therefore, targeting a single hallmark or pathway with a single targeted therapeutic will not be efficient for fighting against tumor heterogeneity. Mesenchymal stem cells (MSCs) possess favorable characteristics for cellular therapy, including their hypoimmune nature, inherent tumor-tropism property, straightforward isolation, and multilineage differentiation potential. MSCs can be loaded with various chemotherapeutics and oncolytic viruses. The combination of these intrinsic features with the possibility of genetic manipulation makes them a versatile tumor delivery vehicle that can be used for in vivo selective tumor delivery of various chemotherapeutic and biological therapeutics. MSCs can be used as biofactory for the local production of chemical or biological anticancer agents at the tumor site. MSC-mediated immunotherapy could facilitate the sustained release of immunotherapeutic agents specifically at the tumor site, and allow for the achievement of therapeutic concentrations without the need for repetitive systemic administration of high therapeutic doses. Despite the enthusiasm evoked by preclinical studies that used MSC in various cancer therapy approaches, the translation of MSCs into clinical applications has faced serious challenges. This manuscript, with a critical viewpoint, reviewed the preclinical and clinical studies that have evaluated MSCs as a selective tumor delivery tool in various cancer therapy approaches, including gene therapy, immunotherapy, and chemotherapy. Then, the novel nanotechnology and bioengineering approaches that can improve the potency of MSC for tumor targeting and overcoming challenges related to their low localization at the tumor sites are discussed.

Signaling crosstalk between mesenchymal stem cells and tumor cells: Implications for tumor suppression or progression

Mesenchymal stem cells (MSCs) have been extensively used in various therapeutic applications over the last two decades, particularly in regenerative medicine and cancer treatment. MSCs have the ability to differentiate into mesodermal and non-mesodermal lineages, which makes them a popular choice in tissue engineering and regenerative medicine. Studies have shown that MSCs have inherent tumor-suppressive properties and can affect the behavior of multiple cells contributing to tumor development. Additionally, MSCs possess a tumor tropism property and have a hypoimmune nature. The intrinsic features of MSCs along with their potential to undergo genetic manipulation and be loaded with various anticancer therapeutics have motivated researchers to use them in different cancer therapy approaches without considering their complex dynamic biological aspects. However, despite their desirable features, several reports have shown that MSCs possess tumor-supportive properties. These contradictory results signify the sophisticated nature of MSCs and warn against the potential therapeutic applications of MSCs. Therefore, researchers should meticulously consider the biological properties of MSCs in preclinical and clinical studies to avoid any undesirable outcomes. This manuscript reviews preclinical studies on MSCs and cancer from the last two decades, discusses how MSC properties affect tumor progression and explains the mechanisms behind tumor suppressive and supportive functions. It also highlights critical cellular pathways that could be targeted in future studies to improve the safety and effectiveness of MSC-based therapies for cancer treatment. The insights obtained from this study will pave the way for further clinical research on MSCs and development of more effective cancer treatments.

Gastric cancer and mesenchymal stem cell-derived exosomes: from pro-tumorigenic effects to anti-cancer vehicles

Gastric cancer (GC) is one of the most prevalent malignancies in the world, with a high mortality rate in both women and men. Conventional treatments, like chemotherapy, radiotherapy and surgery, are facing some drawbacks like acquired drug resistance and various side effects, leading to cancer recurrence and increased morbidity; thus, development of novel approaches in targeted therapy would be very beneficial. Exosomes, extracellular vesicles with a size distribution of sub-150 nm, interplay in physiological and pathophysiological cell-cell communications and can pave the way for targeted cancer therapy. Accumulating pieces of evidence have indicated that exosomes derived from mesenchymal stem cells (MSC-EXs) can act as a double-edged sword in some cancers. The purpose of this review is to assess the differences between stem cell therapy and exosome therapy. Moreover, our aim is to demonstrate how naïve MSCs transform into GC-MSCs in the tumor microenvironment. Additionally, the tumorigenic and anti-proliferation effects of MSC-EXs derived from different origins were investigated. Finally, we suggest potential modifications and combination options that involve utilizing MSC-EXs from the foreskin and umbilical cord as promising sources to enhance the efficacy of gastric cancer treatment. This approach is presented in contrast to bone marrow cells, which are more heterogeneous, age-related, and are also easily affected by the patient's circulation system.

Grb2-related adaptor protein GRAP is a novel regulator of liver fibrosis

AIMS

Excessive liver fibrosis is frequently observed in chronic liver diseases and associated with decline of liver functions. Hepatic stellate cells (HSCs) are considered the principal mediator of liver fibrosis by trans-differentiating into myofibroblasts. In the present study we investigated the role of Grb2-related adaptor protein (GRAP) in HSC activation and liver fibrosis.

METHODS AND MATERIALS

Liver fibrosis was induced by carbon tetrachloride (CCl4) injection. Gene expression was examined by quantitative PCR. Cell proliferation was evaluated by EdU incorporation. DNA-protein interaction was examined by chromatin immunoprecipitation (ChIP).

KEY FINDINGS

GRAP expression was up-regulated during HSC-myofibroblast transition both in vivo and in vitro. Mechanistically, serum response factor (SRF) and myocardin-related transcription factor A (MRTF-A) formed a complex to bind to the GRAP promoter and activate GRAP transcription. Small interfering RNA (siRNA) mediated GRAP silencing blocked HSC-myofibroblast transition in vitro. Importantly, adeno-associated virus 6 (AAV6) mediated GRAP knockdown in myofibroblasts attenuated liver fibrosis in mice. Of note, inhibition of ERK signaling abrogated enhancement of HSC-myofibroblast transition by GRAP over-expression.

SIGNIFICANCE

Our data suggest that GRAP, possibly via ERK activation, regulates HSC-myofibroblast transition and contributes to liver fibrosis. Screening for small-molecule GRAP inhibitors may yield novel therapeutic solutions against liver fibrosis.