Cancer Biology, Epidemiology, and Treatment in the 21st Century: Current Status and Future Challenges From a Biomedical Perspective

Dual-Lock System for High Sensitivity and Selectivity in Redox Enzyme Activation and Imaging

Reductase expression is a potential indicator of cellular pathology. Single-detection systems for reductases have been developed, however, the development of dual-detection systems remain largely unexplored. We rationally designed a dual-lock fluorescent probe that exhibited a high signal-to-noise ratio with a fluorescence Off-On response exclusively for the simultaneous activity of two reductases, NTR and hNQO1, which are overexpressed in cancer hypoxia. The system comprised a naphthalimide fluorophore with dual-lock control mediated by PET and ICT, a trimethyl-locked quinone group sensitive to hNQO1, and a nitrobenzyl carbamate group sensitive to NTR. This study employed a hypoxia model in HeLa cells to demonstrate that our developed dual-lock system detected hypoxia more effectively than single-detection systems. Moreover, it enabled noninvasive real-time monitoring of hypoxia in zebrafish embryos. Consequently, the dual-lock fluorescent probe, which strategically provides a fluorescence response only when both NTR and NQO1 are active, offers a novel diagnostic platform for both in vitro and in vivo applications, effectively detecting hypoxia and monitoring various pathological states.

Combination of gold nanoparticles with near-infrared light as an alternative approach for melanoma management

Melanoma is the most aggressive type of skin cancer and recently approved drugs are often associated with resistance and significant adverse effects. Therefore, the design of more effective and safe options remains imperative. Photothermal therapy (PTT) using gold nanoparticles (AuNPs) presents a promising and innovative approach. In this work, the efficacy of combining a previously optimized formulation of AuNPs coated with a mixture of hyaluronic and oleic acids (HAOA-AuNPs) with near-infrared (NIR) laser irradiation in melanoma cell lines was explored. Coated and uncoated AuNPs formulations were characterized in physicochemical, morphological and elemental terms. Next, the cellular uptake efficiency as well as antiproliferative activity of the combination of each formulation with laser irradiation was evaluated. Subsequently, HAOA-AuNPs were selected to assess the underlying mechanism of combined therapy by cell cycle and Annexin V/PI assays. An in vivo syngeneic murine melanoma model was also conducted. In vitro studies demonstrated that 24 h after incubation and in the absence of laser, HAOA-AuNPs did not exhibit cytotoxic effects on the melanoma cell lines tested, similar to the laser alone. On the contrary, the combination therapy resulted in a large reduction in cell viability. Furthermore, it has been shown to promote S-phase cell cycle arrest and increase in the percentage of late apoptotic cells. Finally, the in vivo proof-of-concept showed that the intratumoral administration of HAOA-AuNPs followed by three laser irradiations impaired tumor progression. Collectively, AuNP-based PTT holds significant potential to improve treatment efficacy and safety, offering a versatile and potent tool against cancer.

A Novel Oncolytic Virus Formulation Based on Mesenchymal Stem Cell-Derived Vesicles for Tumor Therapy

Developing new drug delivery systems is crucial for enhancing the efficacy of oncolytic virus (OV) therapies in cancer treatment. In this study, mesenchymal stem cell (MSC)-derived vesicles and oncolytic viruses are exploited to construct a novel formulation. It has been hypothesized that vesicle-coated OVs could amplify cytotoxic effects through superior internalization by tumor cells. MSC vesicles possess natural tumor homing ability and biocompatibility, which can enhance the targeting, uptake, and therapeutic effects of OVs on tumor cells. Experimental results indicated that this treatment system has increased the apoptosis of tumor cells. Furthermore, flow cytometry analysis demonstrated that the uptake of tumor cells by OVs coated with MSC vesicles soared away compared to uncoated OVs, being 1.5 times than that of the uncoated group. Additionally, the confocal laser scanning microscopy also showed that the fluorescence intensity within tumor cells pretreated with MSC-coated OVs was greater. Meanwhile, propidium iodide (PI) staining revealed that MSC-coated Ovs exposed to tumor cells accelerating the apoptosis of the latter. According to the statistics, the number of dead cells was increased, and the flow cytometry testified that the apoptosis in the MSC-coated OV group was as high as 23.78%. These findings highlight the potential of MSC vesicle-coated OVs in enhancing the delivery and efficacy of oncolytic virus therapy, providing a promising strategy for cancer treatment.

Biological Evaluation of a Rhodium(III) Bipyridylsulfonamide Complex: Effects on Mitochondrial Dynamics and Cytoskeletal Remodeling in Breast Cancer Cells

Rhodium(III) complexes have gained attention for their anticancer potential. In this study, we investigated a rhodium(III) bipyridylsulfonamide complex (2) and its ligand (L) for their effects on breast cancer (SKBr3) and noncancerous mammary cells (HB2). Both compounds significantly reduced oxidative phosphorylation (OXPHOS) and mitochondrial function in SKBr3 cells while sparing HB2 cells. Compound 2 also increased glycolysis in both lines, suggesting a metabolic shift. Mitochondrial size and shape were altered, particularly in SKBr3 cells. Additionally, both compounds reduced cancer cell migration by disrupting actin cytoskeleton organization and the Rac1/VASP signaling pathway. These findings suggest that the rhodium(III) bipyridylsulfonamide complex selectively impairs mitochondrial dynamics and cell migration in cancer cells while sparing healthy cells, providing insight into its mechanism of action and toward its use as targeted anticancer therapy. This study lays the groundwork for future in vivo studies and further optimization of these metal-based therapeutics for clinical applications.

Biomacromolecular hydrogel scaffolds from microfluidics for cancer therapy: A review

Traditional cancer treatment is confronted with the problem of limited therapeutic effect, tissue defects, and lack of drug screening. Hydrogel scaffolds from biological macromolecules based on microfluidic technology are a promising candidate, which can mimic tumor microenvironments to screen personalized drugs, promote the regeneration of healthy tissues, and deliver drugs for enhanced localized antitumor treatment. This review summarizes the latest research on the composition of biomacromolecular hydrogel scaffolds, the architecture of hydrogel scaffolds from microfluidic technology, and their application in cancer therapy, including anti-tumor drug screening, anti-tumor treatment, and anti-tumor treatment and tissue repair. In addition, the potential breakthroughs of this innovative platform in the clinical transformation of cancer therapy are further discussed. The insights revealed in this review are intended to guide the utilization of microfluidic technology-based biomacromolecular hydrogel scaffolds in cancer therapy.

Drug Repurposing for Cancer Treatment: A Comprehensive Review

Cancer ranks among the primary contributors to global mortality. In 2022, the global incidence of new cancer cases reached about 20 million, while the number of cancer-related fatalities reached 9.7 million. In Saudi Arabia, there were 13,399 deaths caused by cancer and 28,113 newly diagnosed cases of cancer. Drug repurposing is a drug discovery strategy that has gained special attention and implementation to enhance the process of drug development due to its time- and money-saving effect. It involves repositioning existing medications to new clinical applications. Cancer treatment is a therapeutic area where drug repurposing has shown the most prominent impact. This review presents a compilation of medications that have been repurposed for the treatment of various types of cancers. It describes the initial therapeutic and pharmacological classes of the repurposed drugs and their new applications and mechanisms of action in cancer treatment. The review reports on drugs from various pharmacological classes that have been successfully repurposed for cancer treatment, including approved ones and those in clinical trials and preclinical development. It stratifies drugs based on their anticancer repurpose as multi-type, type-specific, and mechanism-directed, and according to their pharmacological classes. The review also reflects on the future potential that drug repurposing has in the clinical development of novel anticancer therapies.

Harnessing the power of targeted metal nanocarriers mediated photodynamic and photothermal therapy

The treatment of cancer has become a profoundly intricate procedure. Traditional treatment methods, including chemotherapy, surgery and radiotherapy, have been utilized, while notable progress has been achieved in recent years. Among targeted therapies for cancer, folic acid (FA) conjugated metal-based nanoparticles (NP) have emerged as an innovative strategy, namely for photodynamic therapy (PDT) and photothermal therapy (PTT). These NP exploit the strong attraction between FA and folate receptors, which are excessively produced in several cancer cells, in order to enable precise administration and improved effectiveness of treatment. During PDT, metal-based NP functionalized with FA are used as photosensitizers which are activated by light, and produce reactive oxygen species that cause cancer cells to undergo apoptosis. Within the framework of PTT, these NP effectively transform light energy into concentrated heat, specifically targeting and destroying tumor cells. This review examines the fundamental mechanisms by which these NP improve the effectiveness of PDT and PTT while simultaneously presenting important findings that demonstrate the effectiveness of FA-functionalized MNP in laboratory and animal models. In addition, the paper also discusses the problems and potential directions for their clinical translation.

A review of the potential use of melatonin in cancer treatment: Data analysis from Clinicaltrials.gov

BACKGROUND

Melatonin's antioxidative and immune effects suggest potential in cancer therapy. This review assesses related clinical trials on ClinicalTrials.gov.

METHODS

All ClinicalTrials.gov trials registered up to January 17, 2024 were examined, focusing on trials that involved use of melatonin in cancer treatment. A 46 trials were summarized by their study status, study phase, study type, funder type and study results in the use of melatonin in cancer treatment.

RESULTS

The examination of the research data revealed a collective count of 46 clinical trials enlisted on ClinicalTrials.gov, all focus around the utilization of melatonin in cancer treatment. Among these, 24 trials had reached completion, constituting 91.3% of the entire trials, while 5 trials were presently in the recruitment phase, making up 10.8% of the total. None of these trials had received approval for marketing yet. The majority focus of the analysis encompassed interventional studies, around 42 trials and representing 91.3% of the overall trials, thereby incorporating most enrolled patients. In contrast, observational studies are a smaller fraction, comprising 4 trials (8.6% of the total), with a correspondingly lower number of involved patients. Regarding funding sources, most registered studies secured funding from diverse entities such as individuals, universities, and organizations, constituting 95.6% of all trials. In comparison, a minority of studies received funding from the National Institutes of Health, comprising 5 trials and accounting for 10.8% of the total trials.

CONCLUSION

The analysis of 46 clinical trials on melatonin's use in cancer treatment reveals a significant importance on interventional studies. Overall, these findings contribute to the evolving understanding of melatonin's role in cancer treatment.

Alkaloid-based modulators of the PI3K/Akt/mTOR pathway for cancer therapy: Understandings from pharmacological point of view

This review aims to summarize the role of alkaloids as potential modulators of the PI3K/Akt/mTOR (PAMT) pathway in cancer therapy. The PAMT pathway plays a critical role in cell growth, survival, and metabolism, and its dysregulation contributes to cancer hallmarks. In healthy cells, this pathway is tightly controlled. However, this pathway is frequently dysregulated in cancers and becomes abnormally active. This can happen due to mutations in genes within the pathway itself or due to other factors. This chronic overactivity promotes cancer hallmarks such as uncontrolled cell division, resistance to cell death, and increased blood vessel formation to nourish the tumor. As a result, the PAMT pathway is a crucial therapeutic target for cancer. Researchers are developing drugs that specifically target different components of this pathway, aiming to turn it off and slow cancer progression. Alkaloids, a class of naturally occurring nitrogen-containing molecules found in plants, have emerged as potential therapeutic agents. These alkaloids can target different points within the PAMT pathway, inhibiting its activity and potentially resulting in cancer cell death or suppression of tumor growth. Research is ongoing to explore the role of various alkaloids in cancer treatment. Berberine reduces mTOR activity and increases apoptosis by targeting the PAMT pathway, inhibiting cancer cell proliferation. Lycorine inhibits Akt phosphorylation and mTOR activation, increasing pro-apoptotic protein production and decreasing cell viability. In glioblastoma models, harmine suppresses mTORC1. This review focuses on alkaloids such as evodiamine, hirsuteine, chaetocochin J, indole-3-carbinol, noscapine, berberine, piperlongumine, and so on, which have shown promise in targeting the PAMT pathway. Clinical studies evaluating alkaloids as part of cancer treatment are underway, and their potential impact on patient outcomes is being investigated. In summary, alkaloids represent a promising avenue for targeting the dysregulated PAMT pathway in cancer, and further research is warranted.

The roles of patient-derived xenograft models and artificial intelligence toward precision medicine

Patient-derived xenografts (PDX) involve transplanting patient cells or tissues into immunodeficient mice, offering superior disease models compared with cell line xenografts and genetically engineered mice. In contrast to traditional cell-line xenografts and genetically engineered mice, PDX models harbor the molecular and biologic features from the original patient tumor and are generationally stable. This high fidelity makes PDX models particularly suitable for preclinical and coclinical drug testing, therefore better predicting therapeutic efficacy. Although PDX models are becoming more useful, the several factors influencing their reliability and predictive power are not well understood. Several existing studies have looked into the possibility that PDX models could be important in enhancing our knowledge with regard to tumor genetics, biomarker discovery, and personalized medicine; however, a number of problems still need to be addressed, such as the high cost and time-consuming processes involved, together with the variability in tumor take rates. This review addresses these gaps by detailing the methodologies to generate PDX models, their application in cancer research, and their advantages over other models. Further, it elaborates on how artificial intelligence and machine learning were incorporated into PDX studies to fast-track therapeutic evaluation. This review is an overview of the progress that has been done so far in using PDX models for cancer research and shows their potential to be further improved in improving our understanding of oncogenesis.

Relationship between parental exposure to radiofrequency electromagnetic fields and primarily hematopoietic neoplasms (lymphoma, leukemia) and tumors in the central nervous system in children: a systematic review

Low-frequency electromagnetic fields have grown exponentially in recent years due to technological development and modernization. The World Health Organization (WHO)/International Agency for Research on Cancer (IARC) has classified radiofrequency electromagnetic fields (RF-EMFs) as possibly carcinogenic to humans (Group 2B), and recent studies have investigated the association between exposure to electromagnetic fields in parents and possible health effects in children, especially the development of tumours of the central nervous system (CNS). The objective of this systematic review was to collate all evidence on the relationship between parental occupational exposure to electromagnetic fields and the development of CNS cancer in children and to evaluate this association. This review was prepared according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, Embase, and Web of Science were searched from January 1990 to April 2021. The search was conducted using the following search string: "occupational" AND "child" AND "electromagnetic" AND "cancer". Seventeen articles met our inclusion criteria: 13 case-control studies, two cohort studies, and 2 meta-analyses. Most of the studies showed several methodological weaknesses that limited their results. Due to a lack of consistency regarding the outcome as well as the heterogeneity in the reviewed studies, the body of evidence for the effects of parental exposure to electromagnetic fields is not clear. Methodological heterogeneity in the way that studies were conducted could be responsible for the lack of consistency in the findings. Overall, the body of evidence allows no conclusion on the relationship between parental exposure to electromagnetic fields and the occurrence of CNS tumours in children.

Structure-bioactivity relationship study on anticancer Pd and Pt complexes with aliphatic glycine derivative ligands

To investigate the structure and bioactivity relationship, six Pd(II)/Pt(II) complexes with N-isobutylglycine (L1) and cyclohexylglycine (L2) as N^O amino acid bidentate ligands, 1,10'-phenanthroline (phen) and 2,2'-bipyridine (bipy) as N^N donor ligands, and [Pd(L1)(bipy)]NO3 (1), [Pd(L2)(bipy)]NO3 (2), [Pd(L1)(phen)]NO3 (3), [Pd(L2)(phen)]NO3·2H2O (4), [Pt(L1)(phen)]NO3 (5), along with [Pt(L2)(phen)]NO3 (6) were prepared and then characterized. The geometry of each compound was validated by doing a DFT calculation. Furthermore, tests were conducted on the complexes' water solubilities and lipophilicity. All bipy complexes had superior aqueous solubility and less lipophilicity in comparison with phen complexes, as well as complexes containing cyclohexyl-glycine compared to isobutyl-glycine complexes, probably because of the steric effects and polarity of cyclohexylglycine. The in-vitro anticancer activities of these compounds were examined against HCT116, A549, and MCF7 cancerous cell lines. Data revealed that all Pd/Pt complexes demonstrate higher anticancer activity than carboplatin, and complexes 3 and 4 are more cytotoxic than cisplatin against the HCT116 cell line, particularly against MCF7 cancerous cells. In addition, among all compounds, complex 4 has more anticancer ability than oxaliplatin. Due to different solubility and lipophilicity behavior, the accumulation of Pt complexes and clinical Pt drugs in each cancerous cell was investigated. The binding capabilities of these complexes to DNA, as the main target in chemotherapy, occur through minor grooves and intercalate into DNA, which was done using absorption, fluorescence, and circular dichroism spectroscopy. Finally, the docking simulation study showed the mode of DNA bindings is in good agreement with the spectral binding data.

Diabetes Driven Oncogenesis and Anticancer Potential of Repurposed Antidiabetic Drug: A Systemic Review

Diabetes and cancer are two prevalent disorders, pose significant public health challenges and contribute substantially to global mortality rates, with solely 10 million reported cancer-related deaths in 2020. This review explores the pathological association between diabetes and diverse cancer progressions, examining molecular mechanisms and potential therapeutic intersections. From altered metabolic landscapes to dysregulated signaling pathways, the intricate links are delineated, offering a comprehensive understanding of diabetes as a modulator of tumorigenesis. Cancer cells develop drug resistance through mechanisms like enhanced drug efflux, genetic mutations, and altered drug metabolism, allowing them to survive despite chemotherapeutic agent. Glucose emerges as a pivotal player in diabetes progression, and serving as a crucial energy source for cancer cells, supporting their biosynthetic needs and adaptation to diverse microenvironments. Glycation, a non-enzymatic process that produces advanced glycation end products (AGEs), has been linked to the etiology of cancer and has been shown in a number of tumor forms, such as leiomyosarcomas, adenocarcinomas, and squamous cell carcinomas. Furthermore, in aggressive and metastatic breast cancer, the receptor for AGEs (RAGE) is increased, which may increase the malignancy of the tumor. Reprogramming glucose metabolism manifests as hallmark cancer features, including accelerated cell proliferation, angiogenesis, metastasis, and evasion of apoptosis. This manuscript encapsulates the dual narrative of diabetes as a driver of cancer progression and the potential of repurposed antidiabetic drugs as formidable countermeasures. The amalgamation of mechanistic understanding and clinical trial outcomes establishes a robust foundation for further translational research and therapeutic advancements in the dynamic intersection of diabetes and cancer.

A comprehensive review on lncRNA LOXL1-AS1: molecular mechanistic pathways of lncRNA LOXL1-AS1 in tumorigenicity of cancer cells

Long non-coding RNAs (lncRNAs) are versatile RNAs that regulate various cellular processes, such as gene regulation, by acting as signals, decoys, guides, and scaffolds. A novel recognized lncRNA, LOXL1-antisense RNA 1 (LOXL1-AS1), is dysregulated in some diseases, including cancer, and acts as an oncogenic lncRNA in many types of cancer cells. Upregulation of LOXL1-AS1 has been involved in proliferation, migration, metastasis, and EMT, as well as inhibiting apoptosis in cancer cells. Most importantly, the malignant promoting activity of LOXL1-AS1 can be mostly mediated by sequestering specific miRNAs and inhibiting their binding to the 3´UTR of their target mRNAs, thereby indirectly regulating gene expression. Additionally, LOXL1-AS1 can decoy transcription factors and proteins and prevent their binding to their regulatory regions, inhibiting their mechanistic activity on the regulation of gene expression and signaling pathways. This review presents the mechanistic pathways of the oncogenic role of LOXL1-AS1 by modulating its target miRNAs and proteins in various cancer cells. Having information about the molecular mechanisms regulated by LOXL1-AS1 in cancer cells can open ways to find out particular prognostic biomarkers, as well as discover novel therapeutic approaches for different types of cancer.

Drug resistance mechanisms in cancers: Execution of pro-survival strategies

One of the quintessential challenges in cancer treatment is drug resistance. Several mechanisms of drug resistance have been described to date, and new modes of drug resistance continue to be discovered. The phenomenon of cancer drug resistance is now widespread, with approximately 90% of cancer-related deaths associated with drug resistance. Despite significant advances in the drug discovery process, the emergence of innate and acquired mechanisms of drug resistance has impeded the progress in cancer therapy. Therefore, understanding the mechanisms of drug resistance and the various pathways involved is integral to treatment modalities. In the present review, I discuss the different mechanisms of drug resistance in cancer cells, including DNA damage repair, epithelial to mesenchymal transition, inhibition of cell death, alteration of drug targets, inactivation of drugs, deregulation of cellular energetics, immune evasion, tumor-promoting inflammation, genome instability, and other contributing epigenetic factors. Furthermore, I highlight available treatment options and conclude with future directions.

Combining the amplification refractory mutation system and high-resolution melting analysis for KRAS mutation detection in clinical samples

The success of personalized medicine depends on the discovery of biomarkers that allow oncologists to identify patients that will benefit from a particular targeted drug. Molecular tests are mostly performed using tumor samples, which may not be representative of the tumor's temporal and spatial heterogeneity. Liquid biopsies, and particularly the analysis of circulating tumor DNA, are emerging as an interesting means for diagnosis, prognosis, and predictive biomarker discovery. In this study, the amplification refractory mutation system (ARMS) coupled with high-resolution melting analysis (HRMA) was developed for detecting two of the most relevant KRAS mutations in codon 12. After optimization with commercial cancer cell lines, KRAS mutation screening was validated in tumor and plasma samples collected from patients with pancreatic ductal adenocarcinoma (PDAC), and the results were compared to those obtained by Sanger sequencing (SS) and droplet digital polymerase chain reaction (ddPCR). The developed ARMS-HRMA methodology stands out for its simplicity and reduced time to result when compared to both SS and ddPCR but showing high sensitivity and specificity for the detection of mutations in tumor and plasma samples. In fact, ARMS-HRMA scored 3 more mutations compared to SS (tumor samples T6, T7, and T12) and one more compared to ddPCR (tumor sample T7) in DNA extracted from tumors. For ctDNA from plasma samples, insufficient genetic material prevented the screening of all samples. Still, ARMS-HRMA allowed for scoring more mutations in comparison to SS and 1 more mutation in comparison to ddPCR (plasma sample P7). We propose that ARMS-HRMA might be used as a sensitive, specific, and simple method for the screening of low-level mutations in liquid biopsies, suitable for improving diagnosis and prognosis schemes.

State-of-the-art: MXene structures in nano-oncology

Cancer nanomedicine has been investigated widely and boomed in the last two decades, resulting in designing nanostructures with biofunctionalization, giving rise to an "All-in-One" multifunctional platform. The development of rational design technology with extended functionalities brought interdisciplinary researchers to work continuously, aiming to find a prevent or effectively treat the deadly disease of the century. Thus, it led to some Food and Drug Administration (FDA)-approving nano-based formulations for cancer treatment and opening a vast area of promising discoveries by exploiting different nanomaterials. Two-dimensional (2D) materials have recently gained tremendous interest among scientists because of their outstanding structural, optical, electronic, thermal, and mechanical characteristics. Among various 2D nanomaterials, MXenes are a widely studied nanosystem because of their close similarity to graphene analogs. So, it is synthesized using multiple approaches and exploits their inherited properties. But in most cases, surface functionalization techniques are carried out for targeting, site-specific drug clearance, renal clearance, and biocompatible with healthy cells. Thus, fabricating a multimodal agent for mono or combined therapies is also an image-guided diagnostic agent. This review will explain the recent and emerging advancements of MXenes-based composites as a multifunctional theragnostic agent and discuss the possibilities of transferring laboratory research to clinical translation.

Advanced Cell Therapy: Beyond the last Frontier in the Treatment of Cancer. A Historical Perspective Emphasizing the Work of Nobel Prize Laureates

During the last five decades different therapies have been developed for the treatment of cancer, and as a result, patients can now live longer and better lives. Among such therapies, hematopoietic cell transplantation and immunotherapy have played key roles. In this short article, we present our particular point of view on the development of these two cellular therapies. We have focused on a historical perspective emphasizing the work of some of the Nobel Prize winners whose studies constituted cornerstones in our knowledge of the biology of cancer and in our fight against this devastating disease.

Epigenetic Inheritance From Normal Origin Cells Can Determine the Aggressive Biology of Tumor-Initiating Cells and Tumor Heterogeneity

The acquisition of genetic- and epigenetic-abnormalities during transformation has been recognized as the two fundamental factors that lead to tumorigenesis and determine the aggressive biology of tumor cells. However, there is a regularity that tumors derived from less-differentiated normal origin cells (NOCs) usually have a higher risk of vascular involvement, lymphatic and distant metastasis, which can be observed in both lymphohematopoietic malignancies and somatic cancers. Obviously, the hypothesis of genetic- and epigenetic-abnormalities is not sufficient to explain how the linear relationship between the cellular origin and the biological behavior of tumors is formed, because the cell origin of tumor is an independent factor related to tumor biology. In a given system, tumors can originate from multiple cell types, and tumor-initiating cells (TICs) can be mapped to different differentiation hierarchies of normal stem cells, suggesting that the heterogeneity of the origin of TICs is not completely chaotic. TIC’s epigenome includes not only genetic- and epigenetic-abnormalities, but also established epigenetic status of genes inherited from NOCs. In reviewing previous studies, we found much evidence supporting that the status of many tumor-related “epigenetic abnormalities” in TICs is consistent with that of the corresponding NOC of the same differentiation hierarchy, suggesting that they may not be true epigenetic abnormalities. So, we speculate that the established statuses of genes that control NOC’s migration, adhesion and colonization capabilities, cell-cycle quiescence, expression of drug transporters, induction of mesenchymal formation, overexpression of telomerase, and preference for glycolysis can be inherited to TICs through epigenetic memory and be manifested as their aggressive biology. TICs of different origins can maintain different degrees of innate stemness from NOC, which may explain why malignancies with stem cell phenotypes are usually more aggressive.

Frailty and long-term survival of patients with colorectal cancer: a meta-analysis

BACKGROUND

Frailty has been related with the risk of postoperative complication in patients with colorectal cancer (CRC). However, the association between frailty and long-term survival in patients with CRC has not been comprehensively evaluated. We performed a meta-analysis to systematically evaluate the relationship between frailty and long-term survival of these patients.

METHODS

Relevant cohort studies with follow-up duration ≥ 1 year were identified from Medline, Embase, and Web of Science. A random-effect model after incorporation of the between-study heterogeneity was selected to pool the results.

RESULTS

Ten cohort studies with 35,546 patients were included, and 4100 (11.5%) of them had frailty. Pooled results showed that patients with frailty had worse overall survival compared to those without frailty at baseline (relative risk [RR]: 2.21, 95% confidence interval [CI] 1.43-3.41, P < 0.001; I² = 92%). Results were consistent for studies adjusting age (RR: 2.20, P < 0.001) or including older cancer patients only (RR: 2.28, P = 0.002). Subgroup analyses showed that difference in study design, follow-up duration, or study quality scores may not significantly affect the findings (P for subgroup analyses all > 0.05). Further meta-analyses with two datasets showed that frailty was also associated with worse cancer-specific survival (RR: 4.60, 95% CI 2.75-7.67, P < 0.001; I² = 38%) and recurrence-free survival (RR: 1.72, 95% CI 1.30-2.28, P < 0.001; I² = 0%).

CONCLUSIONS

Frailty at admission is associated with worse survival of patients with colorectal cancer.