A Concise Review: The Role of Stem Cells in Cancer Progression and Therapy

The Impact of Cancer Stem Cells in Colorectal Cancer

Despite incessant research, colorectal cancer (CRC) is still one of the most common causes of fatality in both men and women worldwide. Over time, advancements in medical treatments have notably enhanced the survival rates of patients with colorectal cancer. Managing metastatic CRC involves a complex tradeoff between the potential benefits and adverse effects of treatment, considering factors like disease progression, treatment toxicity, drug resistance, and the overall impact on the patient's quality of life. An increasing body of evidence highlights the significance of the cancer stem cell (CSC) concept, proposing that CSCs occupy a central role in triggering cancer. CSCs have been a focal point of extensive research in a variety of cancer types, including CRC. Colorectal cancer stem cells (CCSCs) play a crucial role in tumor initiation, metastasis, and therapy resistance, making them potential treatment targets. Various methods exist for isolating CCSCs, and understanding the mechanisms of drug resistance associated with them is crucial. This paper offers an overview of the current body of research pertaining to the comprehension of CSCs in colorectal cancer.

The effect of mitochondria inhibition on natural killer cells cytotoxicity in triple-negative breast cancer cells

Triple-Negative Breast Cancer (TNBC), the most common invasive breast cancer, depicts cancer poor response to conventional therapies. The clinical management of TNBC is a challenging issue. Natural killer (NK) cell therapy in the field of cancer treatment is rapidly growing however, regarding the immunogenicity of breast cancer cells, this type of therapy has shown limited efficacy. Recently, targeting tumor biomarkers has revolutionized the field of cancer therapy. Mitochondria affects apoptosis and innate immunity. Therefore, in this study, mitochondria were inhibited with Tigecycline in stimulating the cytotoxicity of NK cells against TNBC cell lines. MDA-MB-468 and MDA-MB-231 were cultured and treated with IC50 (the half-maximal inhibitory concentration) level of Tigecycline for 48 h and afterward co-cultured with peripheral blood NK cells for 5 h. Lastly, the inhibitory effects of mitochondria on the cytotoxicity of NK cells and apoptosis of TNBC cells were evaluated. Moreover, the expression of apoptotic-related genes was studied. The results showed that mitochondria inhibition increased NK cells cytotoxicity against TNBC cells. Moreover, NK cell/mitochondria inhibition in a combinative form improved apoptosis in TNBC cells by the upregulation of Bad and Bid expression. In conclusion, Tigecycline inhibited mitochondria and sensitized TNBC cells to NK cell therapy. Therefore, mitochondria inhibition could help NK cells function properly.

Exploring the promising potential of induced pluripotent stem cells in cancer research and therapy

The advent of iPSCs has brought about a significant transformation in stem cell research, opening up promising avenues for advancing cancer treatment. The formation of cancer is a multifaceted process influenced by genetic, epigenetic, and environmental factors. iPSCs offer a distinctive platform for investigating the origin of cancer, paving the way for novel approaches to cancer treatment, drug testing, and tailored medical interventions. This review article will provide an overview of the science behind iPSCs, the current limitations and challenges in iPSC-based cancer therapy, the ethical and social implications, and the comparative analysis with other stem cell types for cancer treatment. The article will also discuss the applications of iPSCs in tumorigenesis, the future of iPSCs in tumorigenesis research, and highlight successful case studies utilizing iPSCs in tumorigenesis research. The conclusion will summarize the advancements made in iPSC-based tumorigenesis research and the importance of continued investment in iPSC research to unlock the full potential of these cells.

Advancement in precision diagnosis and therapeutic for triple-negative breast cancer: Harnessing diagnostic potential of CRISPR-cas & engineered CAR T-cells mediated therapeutics

Cancer is characterized by uncontrolled cell growth, disrupted regulatory pathways, and the accumulation of genetic mutations. These mutations across different types of cancer lead to disruptions in signaling pathways and alterations in protein expression related to cellular growth and proliferation. This review highlights the AKT signaling cascade and the retinoblastoma protein (pRb) regulating cascade as promising for novel nanotheranostic interventions. Through synergizing state-of-the-art gene editing tools like the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas system with nanomaterials and targeting AKT, there is potential to enhance cancer diagnostics significantly. Furthermore, the integration of modified CAR-T cells into multifunctional nanodelivery systems offers a promising approach for targeted cancer inhibition, including the eradication of cancer stem cells (CSCs). Within the context of highly aggressive and metastatic Triple-negative Breast Cancer (TNBC), this review specifically focuses on devising innovative nanotheranostics. For both pre-clinical and post-clinical TNBC detection, the utilization of the CRISPR-Cas system, guided by RNA (gRNA) and coupled with a fluorescent reporter specifically designed to detect TNBC's mutated sequence, could be promising. Additionally, a cutting-edge approach involving the engineering of TNBC-specific iCAR and syn-Notch CAR T-cells, combined with the co-delivery of a hybrid polymeric nano-liposome encapsulating a conditionally replicative adenoviral vector (CRAdV) against CSCs, could present an intriguing intervention strategy. This review thus paves the way for exciting advancements in the field of nanotheranostics for the treatment of TNBC and beyond.

The role of mesenchymal stem cells derived exosomes as a novel nanobiotechnology target in the diagnosis and treatment of cancer

Mesenchymal stem cells (MSCs), one of the most common types of stem cells, are involved in the modulation of the tumor microenvironment (TME). With the advancement of nanotechnology, exosomes, especially exosomes secreted by MSCs, have been found to play an important role in the initiation and development of tumors. In recent years, nanobiotechnology and bioengineering technology have been gradually developed to detect and identify exosomes for diagnosis and modify exosomes for tumor treatment. Several novel therapeutic strategies bioengineer exosomes to carry drugs, proteins, and RNAs, and further deliver their encapsulated cargoes to cancer cells through the properties of exosomes. The unique properties of exosomes in cancer treatment include targeting, low immunogenicity, flexibility in modification, and high biological barrier permeability. Nevertheless, the current comprehensive understanding of the roles of MSCs and their secreted exosomes in cancer development remain inadequate. It is necessary to better understand/update the mechanism of action of MSCs-secreted exosomes in cancer development, providing insights for better modification of exosomes through bioengineering technology and nanobiotechnology. Therefore, this review focuses on the role of MSCs-secreted exosomes and bioengineered exosomes in the development, progression, diagnosis, and treatment of cancer.

Cellular activation pathways and interaction networks in vascularized composite allotransplantation

Vascularized composite allotransplantation (VCA) is an evolving field of reconstructive surgery that has revolutionized the treatment of patients with devastating injuries, including those with limb losses or facial disfigurement. The transplanted units are typically comprised of different tissue types, including skin, mucosa, blood and lymphatic vasculature, muscle, and bone. It is widely accepted that the antigenicity of some VCA components, such as skin, is particularly potent in eliciting a strong recipient rejection response following transplantation. The fine line between tolerance and rejection of the graft is orchestrated by different cell types, including both donor and recipient-derived lymphocytes, macrophages, and other immune and donor-derived tissue cells (e.g., endothelium). Here, we delineate the role of different cell and tissue types during VCA rejection. Rejection of VCA grafts and the necessity of life-long multidrug immunosuppression remains one of the major challenges in this field. This review sheds light on recent developments in decoding the cellular signature of graft rejection in VCA and how these may, ultimately, influence the clinical management of VCA patients by way of novel therapies that target specific cellular processes.

Magnetic nanoparticle-based hyperthermia: A prospect in cancer stem cell tracking and therapy

Tumor heterogeneity is a major problem in cancer treatment. Cancer stem cells (CSCs) are a subpopulation of tumor masses that produce proliferating and quiescent cells. Under stress-related conditions, quiescent cells are capable of repopulating tumor masses. Consequently, many attempts have been made to identify, isolate, and eradicate CSCs from various tumors. Research has found that quiescent CSCs are less susceptible to conventional therapy than bulk cancer cells. This could be due to reduced cell cycling and increased DNA repair capacity of these cells. Indeed, disease progression is temporarily suppressed by eliminating fast-proliferating tumor cells and sparing quiescent CSCs lead to cancer relapse. Among all the available therapeutic modalities for cancer treatment, hyperthermia uses moderate heat to kill tumor cells. Nanoparticle-based platforms have the potential to deposit heat locally and selectively with the simultaneous activation of nanoparticles as heat transducers. Over the past few decades, magnetic nanoparticles (MNPs) have been widely investigated in the biomedical field. Magnetic hyperthermia therapy (MHT) is a promising therapeutic approach in which MNPs are delivered directly through targeting (systemic) or by direct injection into a tumor under exposure to an alternating magnetic field (AMF). Heat is generated by the MNPs subjected to AMF at a frequency of 100 kHz. Despite the widespread use of MHT alone or in combination therapies, its effectiveness in targeting CSCs remains unclear. This review discusses various types of MHT and their related mechanisms in cancer therapy, particularly concerning the eradication of CSCs.

Thymoquinone-treated mouse mesenchymal stem cells-derived conditioned medium inhibits human breast cancer cells in vitro

Breast cancer is now the most prevalent cancer in females, therefore, it is essential to identify factors affecting its initiation and progression. Mesenchymal stem cells (MSCs) have received considerable attention in stem cell-based therapies and drug delivery applications. Because the therapeutic potential of MSCs is primarily achieved by their paracrine effects, thus identifying and employing bioactive molecules that promote the paracrine activity of MSCs is crucial for their efficient use in cancer treatment. Thymoquinone (TQ) has many biomedical properties, including anti-inflammatory, anti-diabetic, anti-aging, anti-cancer, etc. In addition, it has been found that TQ affects the self-renewal and immunomodulatory properties of MSCs. The present study aimed to investigate the effect of TQ-treated mouse bone marrow-derived MSCs conditioned medium (TQ-MSC-CM) on the biological characteristics of breast cancer cell line MCF7. MSCs were cultured and treated with TQ for 24 h. The TQ-MSC-CM and MSC-CM were collected, and their effects were investigated on ROS production, mitochondrial membrane potential (MMP), cell death, cell cycle, and migration of MCF7 cells by DCFDA-cellular ROS assay, Rhodamine-123 MMP assay, Annexin-PI staining and Caspase-3/7 activity assays, PI-staining and flow-cytometry, and in vitro wound healing assay, respectively. Moreover, the effects of TQ-MSC-CM and MSC-CM were studied on Cdk4, Sox2, c-Met, and Bcl2 gene expression by real-time PCR. Results demonstrated that MSC-CM and TQ-MSC-CM did not have a significant effect on the apoptosis induction in MCF7 cells; however, they significantly stimulated necrosis in the cells. Although TQ-MSC-CM promoted ROS production in MCF7 cells, it decreased the MMP of the cells. TQ-MSC-CM also induced Bcl2 anti-apoptosis gene expression and Casp-3/7 activity in cells. In addition, although MSC-CM induced MCF7 cells to enter the cell cycle, TQ-MSC-CM inhibited its progression. TQ-MSC-CM also downregulated the Cdk4 and Sox2 gene expression. Furthermore, TQ-MSC-CM induced the migration potential of MCF7 in a c-Met-independent manner. Altogether, we conclude that TQ may induce programmed necrosis and inhibits the proliferation and migration of the breast cancer cells by affecting the paracrine activity of MSCs.

Modeling Preclinical Cancer Studies under Physioxia to Enhance Clinical Translation

Oxygen (O2) plays a key role in cellular homeostasis. O2 levels are tightly regulated in vivo such that each tissue receives an optimal amount to maintain physiologic status. Physiologic O2 levels in various organs range between 2% and 9% in vivo, with the highest levels of 9% in the kidneys and the lowest of 0.5% in parts of the brain. This physiologic range of O2 tensions is disrupted in pathologic conditions such as cancer, where it can reach as low as 0.5%. Regardless of the state, O2 tension in vivo is maintained at significantly lower levels than ambient O2, which is approximately 21%. Yet, routine in vitro cellular manipulations are carried out in ambient air, regardless of whether or not they are eventually transferred to hypoxic conditions for subsequent studies. Even brief exposure of hematopoietic stem cells to ambient air can cause detrimental effects through a mechanism termed extraphysiologic oxygen shock/stress (EPHOSS), leading to reduced engraftment capabilities. Here, we provide an overview of the effects of ambient air exposure on stem and non-stem cell subtypes, with a focus on recent findings that reveal the impact of EPHOSS on cancer cells.

Nano-Based Approved Pharmaceuticals for Cancer Treatment: Present and Future Challenges

Cancer is one of the main causes of death worldwide. To date, and despite the advances in conventional treatment options, therapy in cancer is still far from optimal due to the non-specific systemic biodistribution of antitumor agents. The inadequate drug concentrations at the tumor site led to an increased incidence of multiple drug resistance and the appearance of many severe undesirable side effects. Nanotechnology, through the development of nanoscale-based pharmaceuticals, has emerged to provide new and innovative drugs to overcome these limitations. In this review, we provide an overview of the approved nanomedicine for cancer treatment and the rationale behind their designs and applications. We also highlight the new approaches that are currently under investigation and the perspectives and challenges for nanopharmaceuticals, focusing on the tumor microenvironment and tumor disseminate cells as the most attractive and effective strategies for cancer treatments.

Innovation in cancer therapeutics and regulatory perspectives

Cancer therapy has undergone a drastic revolution in the past few decades with the introduction of several novel therapies, like immunotherapy (active and passive), stem cell-based therapies, and nanocarrier-based therapies. These therapies have addressed the issues of conventional cancer therapy (chemotherapy or radiotherapy), like specificity and off-target effects. Further, the introduction of such treatments has improved survival and converted a terminal disease into a more manageable condition. However, many clinical, ethical, and regulatory issues are raised with such novel additions. Several effective therapies are under research but could not come to market or are delayed due to regulatory concerns for marketing approval. The scope of this review encompasses the examination of these regulatory issues and discuss their possible solutions. A practical and flexible regulatory approach, harmonized globally, could help the patients suffering from a terminal illness to lead a quality life.

Lack of CD44 and Sox-2 Overexpression as Two Independent Favourable Prognostic Factors in HPV Positive Patients with Oropharyngeal Cancers

INTRODUCTION

In our earlier publications, in the group of 63 patients with oropharyngeal cancer, we have found HPV16 infection (assessed by qPCR) in 25 tumours (39.7%), immunohistochemical overexpression of CD44, CD98, ALDH1/2 and Nanog in, respectively: 43 (68.2%), 30 (47.6%), 33 (52.4%), and 53 (84.1%) cancers. Analysing CD44, CD98, ALDH1/2, we have also shown that lack of CD44 overexpression indicates excellent prognosis in patients with HPV16 positivity. The aim of the present study was to compare prognostic potential of Nanog, Oct3/4, Sox-2 expression in relation to CD44, CD98, ALDH1/2 immunoreactivity (assessed by us earlier) and clinicopathological features in the subgroups of patients: with HPV16 positivity and HPV16 negativity.

METHODS

Status of Oct3/4 and Sox-2 expression was assessed for 63 patients with oropharyngeal cancers based on immunohistochemistry. In survival analysis, two endpoints were applied: overall survival (OS) and disease-free survival (DFS).

RESULTS

Overexpression of Oct3/4 and Sox-2 was found in 0 (0.0%) and 27 (42.9%) of patients. In the subgroup with HPV16 positivity, the DFS for patients with lack of Sox-2 overexpression was significantly (p = 0.003) higher than for patients with Sox-2 overexpression. In the subgroup with HPV16 negativity, Nanog and Sox-2 immunoexpression did not significantly influence OS and DFS. In multivariate analysis performed for the subgroup with HPV16 positivity, lack of CD44 overexpression (p = 0.012) and lack of Sox-2 overexpression (p = 0.027) were positive independent prognostic factors.

CONCLUSION

Based on CD44 and Sox-2 immunoreactivity, it is possible to differentiate the prognosis of HPV16-positive patients with oropharyngeal cancers.

Cancer Stem Cells and Their Vesicles, Together with Other Stem and Non-Stem Cells, Govern Critical Cancer Processes: Perspectives for Medical Development

Stem cells, identified several decades ago, started to attract interest at the end of the nineties when families of mesenchymal stem cells (MSCs), concentrated in the stroma of most organs, were found to participate in the therapy of many diseases. In cancer, however, stem cells of high importance are specific to another family, the cancer stem cells (CSCs). This comprehensive review is focused on the role and the mechanisms of CSCs and of their specific extracellular vesicles (EVs), which are composed of both exosomes and ectosomes. Compared to non-stem (normal) cancer cells, CSCs exist in small populations that are preferentially distributed to the niches, such as minor specific tissue sites corresponding to the stroma of non-cancer tissues. At niches and marginal sites of other cancer masses, the tissue exhibits peculiar properties that are typical of the tumor microenvironment (TME) of cancers. The extracellular matrix (ECM) includes components different from non-cancer tissues. CSCs and their EVs, in addition to effects analogous to those of MSCs/EVs, participate in processes of key importance, specific to cancer: generation of distinct cell subtypes, proliferation, differentiation, progression, formation of metastases, immune and therapy resistance, cancer relapse. Many of these, and other, effects require CSC cooperation with surrounding cells, especially MSCs. Filtered non-cancer cells, especially macrophages and fibroblasts, contribute to collaborative cancer transition/integration processes. Therapy developments are mentioned as ongoing preclinical initiatives. The preliminary state of clinical medicine is presented in terms of both industrial development and future treatments. The latter will be administered to specific patients together with known drugs, with the aim of eradicating their tumor growth and metastases.