IL-8 regulates the doxorubicin resistance of colorectal cancer cells via modulation of multidrug resistance 1 (MDR1)

Doxorubicin-induced chemoresistance in Duke's type B colon adenocarcinoma cell line is aggravated in the presence of TGF-β2 through non-apoptotic cell death

BACKGROUND

The current challenge in clinical cancer treatment is chemoresistance. Colon cells have inherently higher xenobiotic transporters expression and hence can attain resistance rapidly. Increased levels of TGF-β2 expression in patients have been attributed to cancer progression, aggressiveness, and resistance. To investigate resistance progression, we treated doxorubicin (dox) to HT-29 colon adenocarcinoma cells in the presence or absence of TGF-β2 ligand.

METHODS

After 1, 3-, and 7-day treatment, we investigated cell proliferation, viability, and cytotoxicity by MTT, trypan blue staining, and lactate dehydrogenase enzyme release. The mechanism of cell death was elucidated by hoechst33342 and propidium iodide dual staining and apoptosis assay. The development of resistance was detected by rhodamine123 efflux and P-glycoprotein (P-gp)/MDR1 antibody staining through fluorimetry and flow cytometry. The colony formation ability of the cells was also elucidated.

RESULTS

Inhibition of cell proliferation was noted after day 1, while a significant reduction in viability and a significant increase in lactate dehydrogenase release was detected after day 3. Reduction of intracellular rhodamine123 levels was detected after day 3 and was significantly lower in dox with TGF-β2 treatment compared to dox alone. Increased surface P-gp levels after days 3 and 7 were observed in the treated groups. Hoechst33342/propidium iodide staining and apoptosis assay indicated non-apoptotic cell death. The cells treated with TGF-β2 had higher colony formation ability.

CONCLUSIONS

TGF-β2 expression might play a significant role in the development of chemoresistance to doxorubicin in Duke's type B colon adenocarcinoma cell line, HT-29.

Impact of laparoscopic versus open surgery on humoral immunity in patients with colorectal cancer: a systematic review and meta-analysis

BACKGROUND

Laparoscopic surgery (LS) is hypothesized to result in milder proinflammatory reactions due to less severe operative trauma, which may contribute to the observed clinical benefits after LS. However, previous systematic reviews and meta-analyses on the impact of LS on immunocompetence are outdated, limited and heterogeneous. Therefore, the humoral response after laparoscopic and open colorectal cancer (CRC) resections was evaluated in a comprehensive systematic review and meta-analysis.

METHODS

Included were randomized controlled trials (RCTs) measuring parameters of humoral immunity after LS compared to open surgery (OS) in adult patients with CRC of any stage. MEDLINE, Embase, Web of Science (SCI-EXPANDED), Cochrane Library, Google Scholar, ClinicalTrials.gov and ICTRP (World Health Organization) were systematically searched. Risk of bias (RoB) was assessed using the Cochrane RoB2 tool. Weighted inverse variance meta-analysis of mean differences was performed for C-reactive protein (CRP), interleukin (IL)-6, IL-8, tumour necrosis factor (TNF)α and vascular endothelial growth factor (VEGF) using the random-effects method. Methods were prospectively registered in PROSPERO (CRD42021264324).

RESULTS

Twenty RCTs with 1131 participants were included. Narrative synthesis and meta-analysis up to 8 days after surgery was performed. Quantitative synthesis found concentrations to be significantly lower after LS at 0-2 h after surgery (IL-8), at 3-9 h (CRP, IL-6, IL-8, TNFα) and at postoperative day 1 (CRP, IL-6, IL-8, VEGF). At 3-9 h, IL-6 was notably lower in the LS group by 86.71 pg/ml (mean difference [MD] - 86.71 pg/ml [- 125.05, - 48.37], p < 0.00001). Combined narratively, 13 studies reported significantly lower concentrations of considered parameters in LS patients, whereas only one study reported lower inflammatory markers (for CRP and IL-6) after OS.

CONCLUSION

The increase in postoperative concentrations of several proinflammatory parameters was significantly less pronounced after LS than after OS in this meta-analysis. Overall, the summarized evidence reinforces the view of a lower induction of inflammation due to LS.

Deciphering treatment resistance in metastatic colorectal cancer: roles of drug transports, EGFR mutations, and HGF/c-MET signaling

In 2023, colorectal cancer (CRC) is the third most diagnosed malignancy and the third leading cause of cancer death worldwide. At the time of the initial visit, 20% of patients diagnosed with CRC have metastatic CRC (mCRC), and another 25% who present with localized disease will later develop metastases. Despite the improvement in response rates with various modulation strategies such as chemotherapy combined with targeted therapy, radiotherapy, and immunotherapy, the prognosis of mCRC is poor, with a 5-year survival rate of 14%, and the primary reason for treatment failure is believed to be the development of resistance to therapies. Herein, we provide an overview of the main mechanisms of resistance in mCRC and specifically highlight the role of drug transports, EGFR, and HGF/c-MET signaling pathway in mediating mCRC resistance, as well as discuss recent therapeutic approaches to reverse resistance caused by drug transports and resistance to anti-EGFR blockade caused by mutations in EGFR and alteration in HGF/c-MET signaling pathway.

Protein post-translational modifications: A key factor in colorectal cancer resistance mechanisms

Colorectal cancer (CRC) is one of the leading causes of cancer-related death. Despite advances in treatment, drug resistance remains a critical impediment. Post-translational modifications (PTMs) regulate protein stability, localization, and activity, impacting vital cellular processes. Recent research has highlighted the essential role of PTMs in the development of CRC resistance. This review summarizes recent advancements in understanding PTMs' roles in CRC resistance, focusing on the latest discoveries. We discuss the functional impact of PTMs on signaling pathways and molecules involved in CRC resistance, progress in drug development, and potential therapeutic targets. We also summarize the primary enrichment methods for PTMs. Finally, we discuss current challenges and future directions, including the need for more comprehensive PTM analysis methods and PTM-targeted therapies. This review identifies potential therapeutic interventions for addressing medication resistance in CRC, proposes prospective therapeutic options, and gives an overview of the function of PTMs in CRC resistance.

Immune checkpoint blockade induced shifts in cytokine expression patterns in peripheral blood of head and neck cancer patients are linked to outcome

Background

Immune-checkpoint blockade (ICB) of programmed-death-1 (PD-1) with pembrolizumab or nivolumab is approved for treating recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC). NadiHN and ADRISK are phase IIB trials investigating in locally advanced (LA) HNSCC having low or high risk of recurrence the potential benefits from adding nivolumab to post-operative radiotherapy or pembrolizumab to cisplatin-based radio-chemotherapy.

Methods

Along five randomized controlled ICB trials including NadiHN and ADRISK, blood samples were taken before and after starting ICB in n=25 patients. Concentrations of vascular endothelial growth factor A (VEGF), CCL2 (MCP-1), interleukin-6 (IL-6), IL-8, interferon-gamma (IFN-γ), and CXCL10 (IP-10) pre- and post-ICB in EDTA-anticoagulated plasma and serum were compared. We used receiver operating characteristic (ROC) curves to identify optimal cutoff for defining subgroups before analyzing overall survival (OS) applying Kaplan-Meier plots and multivariate Cox regression.

Results

We detected huge heterogeneity between cytokine patterns in pre-and post-ICB plasma and serum. We observed high correlation between concentrations of some cytokines. Despite absent systematic OS differences after ICB with pembrolizumab or nivolumab or between LA-HNSCC versus R/M HNSCC patients, we noticed improved outcome of patients having lower IFN-γ concentrations pre- and post-ICB and following ICB reduced concentrations of VEGF, IL-6, and IL-8 but not MCP-1. Contrarily, increases in IL-6, IL-8, and VEGF levels correlated with impaired outcome. Multivariate Cox regression revealed five independent OS predictors among cytokines; using natural logarithms of their hazard ratios to estimate an individual's risk of dying, three cytokine-expression pattern (CEP)-risk groups with no death within mean (95% confidence interval) follow-up of 29.2 (22.1-36.2) months and median OS of 11.3 (8.8-13.8) and 2.9 (0.4-5.4) months were found.

Conclusion

Whereas individual pre- or post-ICB cytokine concentrations in serum or plasma alone failed to predict the survivor group, CEP-risk groups may support the identification of individual patients with long-lasting benefit from ICB.

Epidemiology and nomogram of pediatric and young adulthood osteosarcoma patients with synchronous lung metastasis: A SEER analysis

BACKGROUND

Patients with osteosarcoma and synchronous lung metastasis (SLM) have poor survival. This study aimed to explore the epidemiology data and construct a predictive nomogram to identify cases at risk of SLM occurrence among pediatric and young adulthood osteosarcoma patients.

METHODS

All data were extracted from Surveillance, Epidemiology, and End Results 17 registries. The age-standardized incidence rate (ASIR) and annual percentage change was evaluated, and reported for the overall population and by age, gender, race, and primary site. Univariate and multivariate logistic regression analyses were used to identify risk factors associated with SLM occurrence, then significant factors were used to develop the nomogram. The area under the receiver operating characteristic curve (AUC) and calibration curve were used to evaluated the predictive power of the nomogram. Survival analysis was assessed by the Kaplan-Meier method and the log-rank test. Multivariate Cox analysis was used to determine the prognostic factors.

RESULTS

A total of 278 out of 1965 patients (14.1%) presented with SLM at diagnosis. The ASIR increased significant from 0.46 to 0.66 per 1,000,000 person-years from year 2010 to 2019, with an annual percentage change of 3.5, mainly in patients with age 10-19 years, male and appendicular location. All patients were randomly assigned into train cohort and validation cohort with a spilt of 7:3. In the train cohort, higher tumor grade, bigger tumor size, positive lymph nodes and other site-specific metastases (SSM) were identified as significant risk factors associated with SLM occurrence. Then a nomogram was developed based on the four factors. The AUC and calibration curve in both train and validation cohorts demonstrated that the nomogram had moderate predictive power. The median cancer-specific survival was 25 months. Patients with age 20-39 years, male, positive lymph nodes, other SSM were adverse prognostic factors, while surgery was protective factor.

CONCLUSIONS

This study performed a comprehensive analysis regarding pediatric and young adulthood osteosarcoma patients had SLM. A visual, clinically operable, and easy-to-interpret nomogram model was developed for predicting the risk of SLM, which could be used in clinic and help clinicians make better decisions.

Targeted blockade of interleukin-8 negates metastasis and chemoresistance via Akt/Erk-NFκB axis in oral cancer

BACKGROUND

The tumor microenvironment plays a significant role in tumor growth, metastasis and chemoresistance via dysregulated signaling pathways. Toward this, an inflammatory chemokine, interleukin-8 (IL-8), is overexpressed in various cancers and is involved in tumor progression and chemoresistance. However, the mechanistic role of IL-8 in mediating metastasis and chemoresistance in oral squamous cell carcinoma (OSCC) is not known.

METHODS AND RESULTS

In the present study, we evaluated the effect of IL-8 in regulating metastasis as well as chemoresistance in OSCC cell lines. For this, IL-8 was blocked exogenously using neutralizing IL-8 monoclonal antibody and IL-8 levels were enhanced by exogenous supply of recombinant human IL-8 (rhIL-8) to OSCC cells. The epithelial-to-mesenchymal transition (EMT) was evaluated using qPCR, migration by scratch/wound healing assay and invasion ability using transwell assay. rIL-8 induced chemoresistance was studied by apoptosis assay and the nuclear localization of NFκB using immunocytochemistry. IL-8 was significantly overexpressed in OSCC patients and cell lines. While exogenous blockade of IL-8 significantly reduced EMT, migration and invasion potential in OSCC cells, IL-8 overexpression upregulated these cellular traits thereby confirming the role of IL-8 in OSCC metastasis. Exogenous blockade of IL-8 also reversed chemoresistance in cisplatin resistant OSCC subline via NFκB signaling.

CONCLUSION

IL-8 plays a crucial role in OSCC metastasis and its targeted blockade can help in management of cisplatin resistance.

Application of nanotechnology in reversing therapeutic resistance and controlling metastasis of colorectal cancer

Colorectal cancer (CRC) is the most common digestive malignancy across the world. Its first-line treatments applied in the routine clinical setting include surgery, chemotherapy, radiotherapy, targeted therapy, and immunotherapy. However, resistance to therapy has been identified as the major clinical challenge that fails the treatment method, leading to recurrence and distant metastasis. An increasing number of studies have been attempting to explore the underlying mechanisms of the resistance of CRC cells to different therapies, which can be summarized into two aspects: (1) The intrinsic characters and adapted alterations of CRC cells before and during treatment that regulate the drug metabolism, drug transport, drug target, and the activation of signaling pathways; and (2) the suppressive features of the tumor microenvironment (TME). To combat the issue of therapeutic resistance, effective strategies are warranted with a focus on the restoration of CRC cells’ sensitivity to specific treatments as well as reprogramming impressive TME into stimulatory conditions. To date, nanotechnology seems promising with scope for improvement of drug mobility, treatment efficacy, and reduction of systemic toxicity. The instinctive advantages offered by nanomaterials enable the diversity of loading cargoes to increase drug concentration and targeting specificity, as well as offer a platform for trying the combination of different treatments to eventually prevent tumor recurrence, metastasis, and reversion of therapy resistance. The present review intends to summarize the known mechanisms of CRC resistance to chemotherapy, radiotherapy, immunotherapy, and targeted therapy, as well as the process of metastasis. We have also emphasized the recent application of nanomaterials in combating therapeutic resistance and preventing metastasis either by combining with other treatment approaches or alone. In summary, nanomedicine is an emerging technology with potential for CRC treatment; hence, efforts should be devoted to targeting cancer cells for the restoration of therapeutic sensitivity as well as reprogramming the TME. It is believed that the combined strategy will be beneficial to achieve synergistic outcomes contributing to control and management of CRC in the future.

Paracrine secretion of IL8 by breast cancer stem cells promotes therapeutic resistance and metastasis of the bulk tumor cells

BACKGROUND

Breast tumors consist of heterogeneous cellular subpopulations that differ in molecular properties and functional attributes. Cancer stem cells (CSCs) play pivotal roles in cancer therapeutic failure and metastasis. However, it remains indeterminate how CSCs determine the progression of the bulk cancer cell population.

METHODS

Co-culture systems in vitro and co-implantation systems in vivo were designed to characterize the interactions between breast cancer stem cells (BCSCs) and bulk cancer cells. RNA sequencing was performed to study the functional and mechanistic implications of the BCSC secretome on bulk cancer cells. A cytokine antibody array was employed to screen the differentially secreted cytokines in the BCSC secretome. Tail vein injection metastatic models and orthotopic xenograft models were applied to study the therapeutic potential of targeting IL8.

RESULTS

We identified that the BCSC secretome potentiated estrogen receptor (ER) activity in the bulk cancer cell population. The BCSC secretome rendered the bulk cancer cell population resistant to anti-estrogen and CDK4/6 inhibitor therapy; as well as increased the metastatic burden attributable to bulk cancer cells. Screening of the BCSC secretome identified IL8 as a pivotal factor that potentiated ERα activity, endowed tamoxifen resistance and enhanced metastatic burden by regulation of bulk cancer cell behavior. Pharmacological inhibition of IL8 increased the efficacy of fulvestrant and/or palbociclib by reversing tamoxifen resistance and abrogated metastatic burden.

CONCLUSION

Taken together, this study delineates the mechanism by which BCSCs determine the therapeutic response and metastasis of bulk cancer cells; and thereby suggests potential therapeutic strategies to ameliorate breast cancer outcomes. Video Abstract.

Molecular mechanisms targeting drug-resistance and metastasis in colorectal cancer: Updates and beyond

Colorectal cancer (CRC) is the third most diagnosed malignancy and a major leading cause of cancer-related deaths worldwide. Despite advances in therapeutic regimens, the number of patients presenting with metastatic CRC (mCRC) is increasing due to resistance to therapy, conferred by a small population of cancer cells, known as cancer stem cells. Targeted therapies have been highly successful in prolonging the overall survival of patients with mCRC. Agents are being developed to target key molecules involved in drug-resistance and metastasis of CRC, and these include vascular endothelial growth factor, epidermal growth factor receptor, human epidermal growth factor receptor-2, mitogen-activated extracellular signal-regulated kinase, in addition to immune checkpoints. Currently, there are several ongoing clinical trials of newly developed targeted agents, which have shown considerable clinical efficacy and have improved the prognosis of patients who do not benefit from conventional chemotherapy. In this review, we highlight recent developments in the use of existing and novel targeted agents against drug-resistant CRC and mCRC. Furthermore, we discuss limitations and challenges associated with targeted therapy and strategies to combat intrinsic and acquired resistance to these therapies, in addition to the importance of implementing better preclinical models and the application of personalized therapy based on predictive biomarkers for treatment selection.

Canine osteosarcoma in comparative oncology: Molecular mechanisms through to treatment discovery

Cancer is a leading cause of non-communicable morbidity and mortality throughout the world, similarly, in dogs, the most frequent cause of mortality is tumors. Some types of cancer, including osteosarcoma (OSA), occur at much higher rates in dogs than people. Dogs therefore not only require treatment themselves but can also act as an effective parallel patient population for the human disease equivalent. It should be noted that although there are many similarities between canine and human OSA, there are also key differences and it is important to research and highlight these features. Despite progress using chorioallantoic membrane models, 2D and 3D in vitro models, and rodent OSA models, many more insights into the molecular and cellular mechanisms, drug development, and treatment are being discovered in a variety of canine OSA patient populations.

Cytokine-mediated crosstalk between cancer stem cells and their inflammatory niche from the colorectal precancerous adenoma stage to the cancerous stage: Mechanisms and clinical implications

The majority of colorectal cancers (CRCs) are thought to arise from precancerous adenomas. Upon exposure to diverse microenvironmental factors, precancerous stem cells (pCSCs) undergo complex genetic/molecular changes and gradually progress to form cancer stem cells (CSCs). Accumulative evidence suggests that the pCSC/CSC niche is an inflammatory dominated milieu that contains different cytokines that function as the key communicators between pCSCs/CSCs and their niche and have a decisive role in promoting CRC development, progression, and metastasis. In view of the importance and increasing data about cytokines in modulating pCSCs/CSC stemness properties and their significance in CRC, this review summarizes current new insights of cytokines, such as interleukin (IL)-4, IL-6, IL-8, IL-17A, IL-22, IL-23, IL-33 and interferon (IFN)-γ, involving in the modulation of pCSC/CSC properties and features in precancerous and cancerous lesions and discusses the possible mechanisms of adenoma progression to CRCs and their therapeutic potential.

Interleukin-8 in Colorectal Cancer: A Systematic Review and Meta-Analysis of Its Potential Role as a Prognostic Biomarker

Among soluble actors that have emerged as druggable factors, the chemokine interleukin-8 (IL-8) has emerged as a possible determinant of response to immunotherapy and targeted treatment in several cancer types; however, its prognostic/predictive role in colorectal cancer (CRC) remains to be established. We: (i) conducted a systematic review of published literature on IL-8 expression in CRC; (ii) searched public transcriptomics databases; (iii) investigated IL-8 expression, by tumor and infiltrating cells, in a series of CRC samples; and (iv) carried out a meta-analysis of published literature correlating IL-8 expression and CRC prognosis. IL-8 possesses an important role as a mediator of the bidirectional crosstalk between tumor/stromal cells. Transcriptomic analysis indicated that specific IL-8 transcripts were significantly overexpressed in CRC compared to normal colon mucosa. Moreover, in our series we observed a statistically significant correlation between PTEN-loss and IL-8 expression by infiltrating mononuclear and tumor cells. In total, 12 papers met our meta-analysis inclusion criteria, demonstrating that high IL-8 levels significantly correlated with shorter overall survival and progression-free survival. Sensitivity analysis demonstrated a highly significant correlation with outcome for circulating, but not for tissue-detected, IL-8. IL-8 is overexpressed in CRC tissues and differentially produced by tumor or stromal components depending on CRC genetic background. Moreover, circulating IL-8 represents a strong prognostic factor in CRC, suggesting its use in the refining of prognostic CRC assessment and potentially the tailoring of therapeutic strategies in individual CRC patients.

Drug Resistance in Colorectal Cancer: From Mechanism to Clinic

Colorectal cancer (CRC) is one of the leading causes of death worldwide. The 5-year survival rate is 90% for patients with early CRC, 70% for patients with locally advanced CRC, and 15% for patients with metastatic CRC (mCRC). In fact, most CRC patients are at an advanced stage at the time of diagnosis. Although chemotherapy, molecularly targeted therapy and immunotherapy have significantly improved patient survival, some patients are initially insensitive to these drugs or initially sensitive but quickly become insensitive, and the emergence of such primary and secondary drug resistance is a significant clinical challenge. The most direct cause of resistance is the aberrant anti-tumor drug metabolism, transportation or target. With more in-depth research, it is found that cell death pathways, carcinogenic signals, compensation feedback loop signal pathways and tumor immune microenvironment also play essential roles in the drug resistance mechanism. Here, we assess the current major mechanisms of CRC resistance and describe potential therapeutic interventions.

Natural Compounds Targeting Cancer-Associated Fibroblasts against Digestive System Tumor Progression: Therapeutic Insights

Cancer-associated fibroblasts (CAFs) are critical for cancer occurrence and progression in the tumor microenvironment (TME), due to their versatile roles in extracellular matrix remodeling, tumor–stroma crosstalk, immunomodulation, and angiogenesis. CAFs are the most abundant stromal component in the TME and undergo epigenetic modification and abnormal signaling cascade activation, such as transforming growth factor-β (TGF-β) and Wnt pathways that maintain the distinct phenotype of CAFs, which differs from normal fibroblasts. CAFs have been considered therapeutic targets due to their putative oncogenic functions. Current digestive system cancer treatment strategies often result in lower survival outcomes and fail to prevent cancer progression; therefore, comprehensive characterization of the tumor-promoting and -restraining CAF activities might facilitate the design of new therapeutic approaches. In this review, we summarize the enormous literature on natural compounds that mediate the crosstalk of CAFs with digestive system cancer cells, discuss how the biology and the multifaceted functions of CAFs contribute to cancer progression, and finally, pave the way for CAF-related antitumor therapies.

Extracellular Vesicle-Mediated IL-1 Signaling in Response to Doxorubicin Activates PD-L1 Expression in Osteosarcoma Models

The expression of programmed cell death ligand 1 (PD-L1) in tumors is associated with tumor cell escape from T-cell cytotoxicity, and is considered a crucial effector in chemoresistance and tumor relapse. Although PD-L1 induction has been observed in patients after chemotherapy treatment, the mechanism by which the drug activates PD-L1 expression remains elusive. Here, we identified the extracellular vesicles (EVs) as a molecular mediator that determines the effect of doxorubicin on PD-L1 expression in osteosarcoma models. Mechanistically, doxorubicin dependently stimulates the release of extracellular vesicles, which mediate autocrine/paracrine signals in osteosarcoma cells. The recipient cells were stimulated by these EVs and acquired the ability to promote the expression of inflammatory cytokines interleukin (IL)-1β and IL-6. In response to doxorubicin, IL-1β, but not IL-6, allowed- osteosarcoma cells to promote the expression of PD-L1, and the elimination of IL-1β/IL-1 receptor signaling with IL-1 receptor antagonist reduced PD-L1 expression. Together, these findings provided insights into the role of EV release in response to chemotherapy that mediates PD-L1 expression via the IL-1 signaling pathway, and suggested that the combination of a drug targeting IL-1 or PD-L1 with chemotherapy could be an effective treatment option for osteosarcoma patients.

Small Interfering RNA in Colorectal Cancer Liver Metastasis Therapy

Colorectal cancer (CRC) is associated with numerous genetic disorders and cellular abnormalities, and liver metastasis is a common health concern in patients with CRC. Exploring newer and more efficient therapies to block liver metastasis is pivotal for prolonging patient survival. Therefore, small interfering RNAs (siRNAs) are expected to be remarkable tools capable of regulating gene expression by participating in a process called RNA interference (RNAi). RNAi is a biological process among eukaryotes wherein specific messenger RNA (mRNA) molecules are destroyed and gene expression is inhibited. This technology is a promising therapeutic agent in the treatment of CRC liver metastasis (CRLM). Nevertheless, crucial problems in siRNA therapeutics, including inherent poor serum stability and nonspecific uptake into biological systems, must be recognized. For this reason, delivery systems are being developed in an attempt to solve these problems. Here, we discuss the utility of siRNA therapy for the treatment of CRCLM by targeting the major metastasis-related signaling pathways. siRNA therapy has the potential to be one of the most effective methods for CRLM treatment in the future.

Comprehensive Omics Analysis of a Novel Small-Molecule Inhibitor of Chemoresistant Oncogenic Signatures in Colorectal Cancer Cell with Antitumor Effects

Tumor recurrence from cancer stem cells (CSCs) and metastasis often occur post-treatment in colorectal cancer (CRC), leading to chemoresistance and resistance to targeted therapy. MYC is a transcription factor in the nuclei that modulates cell growth and development, and regulates immune response in an antitumor direction by mediating programmed death ligand 1 (PD-L1) and promoting CRC tumor recurrence after adjuvant chemotherapy. However, the molecular mechanism through which c-MYC maintains stemness and confers treatment resistance still remains elusive in CRC. In addition, recent reports demonstrated that CRC solid colon tumors expresses C-X-C motif chemokine ligand 8 (CXCL8). Expression of CXCL8 in CRC was reported to activate the expression of PD-L1 immune checkpoint through c-MYC, this ultimately induces chemoresistance in CRC. Accumulating studies have also demonstrated increased expression of CXCL8, matrix metalloproteinase 7 (MMP7), tissue inhibitor of metalloproteinase 1 (TIMP1), and epithelial-to-mesenchymal transition (EMT) components, in CRC tumors suggesting their potential collaboration to promote EMT and CSCs. TIMP1 is MMP-independent and regulates cell development and apoptosis in various cancer cell types, including CRC. Recent studies showed that TIMP1 cleaves CXCL8 on its chemoattractant, thereby influencing its mechanistic response to therapy. This therefore suggests crosstalk among the c-MYC/CXCL8/TIMP1 oncogenic signatures. In this study, we explored computer simulations through bioinformatics to identify and validate that the MYC/CXCL8/TIMP1 oncogenic signatures are overexpressed in CRC, Moreover, our docking results exhibited putative binding affinities of the above-mentioned oncogenes, with our novel small molecule, RV59, Finally, we demonstrated the anticancer activities of RV59 against NCI human CRC cancer cell lines both as single-dose and dose-dependent treatments, and also demonstrated the MYC/CXCL8/TIMP1 signaling pathway as a potential RV59 drug target.

Interleukin-6 reverses Adriamycin resistance in nasal NK/T-cell lymphoma via downregulation of ABCC4 and inactivation of the JAK2/STAT3/NF-κB/P65 pathway

Chemotherapy is generally effective for extranodal natural killer (NK)/T-cell lymphoma (ENKTCL), nasal type. Nevertheless, multidrug resistance (MDR) remains a key challenge in treating nasal NK/T-cell lymphoma. Interleukin-6 (IL-6) is reportedly an important regulator of MDR in many cancers, implicating a role of IL-6 in the chemotherapy response. However, the effects and mechanism of IL-6 in nasal NK/T-cell lymphoma remain unclear. Herein, we demonstrated that the IL-6 serum level was decreased in nasal NK/T-cell lymphoma patients compared to chronic rhinitis patients. Lower serum levels of IL-6 were closely correlated with Ki67 expression and patient survival. ATP-binding cassette (ABC) drug transporter ABCC4 in patients was abnormally upregulated. IL-6 significantly inhibited resistance to Adriamycin (ADM) in ADM-resistant SNK-6 cells (SNK-6/ADM). Moreover, IL-6 resulted in cell cycle arrest and led to apoptosis in SNK-6/ADM cells. Furthermore, IL-6 decreased ABCC4, p-JAK2, p-STAT3, and phospho-NF-κB p65 expression in SNK-6/ADM cells. IL-6 in combination with ADM inhibited tumor growth and increased the survival of SNK-6/ADM xenograft mice. In conclusion, our findings suggest that IL-6 can inhibit the upregulation of ABCC4 and inactivate the JAK2/STAT3/NF-κB/P65 pathway to sensitize NK/T-cell lymphoma to ADM, indicating that combination therapy with IL-6 and other chemotherapeutic drugs may be effective in reversing acquired resistance in nasal NK/T-cell lymphoma.

The Mechanistic Roles of ncRNAs in Promoting and Supporting Chemoresistance of Colorectal Cancer

Colorectal Cancer (CRC) is one of the most common gastrointestinal malignancies which has quite a high mortality rate. Despite the advances made in CRC treatment, effective therapy is still quite challenging, particularly due to resistance arising throughout the treatment regimen. Several studies have been carried out to identify CRC chemoresistance mechanisms, with research showing different signalling pathways, certain ATP binding cassette (ABC) transporters and epithelial mesenchymal transition (EMT), among others to be responsible for the failure of CRC chemotherapies. In the last decade, it has become increasingly evident that certain non-coding RNA (ncRNA) families are involved in chemoresistance. Research investigations have demonstrated that dysregulation of microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) contribute towards promoting resistance in CRC via different mechanisms. Considering the currently available data on this phenomenon, a better understanding of how these ncRNAs participate in chemoresistance can lead to suitable solutions to overcome this problem in CRC. This review will first focus on discussing the different mechanisms of CRC resistance identified so far. The focus will then shift onto the roles of miRNAs, lncRNAs and circRNAs in promoting 5-fluorouracil (5-FU), oxaliplatin (OXA), cisplatin and doxorubicin (DOX) resistance in CRC, specifically using ncRNAs which have been recently identified and validated under in vivo or in vitro conditions.

Identification of intestinal flora-related key genes and therapeutic drugs in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is a multifactorial tumor and a leading cause of cancer-specific deaths worldwide. Recent research has shown that the alteration of intestinal flora contributes to the development of CRC. However, the molecular mechanism by which intestinal flora influences the pathogenesis of CRC remains unclear. This study aims to explore the key genes underlying the effect of intestinal flora on CRC and therapeutic drugs for CRC.

METHODS

Intestinal flora-related genes were determined using text mining. Based on The Cancer Genome Atlas database, differentially expressed genes (DEGs) between CRC and normal samples were identified with the limma package of the R software. Then, the intersection of the two gene sets was selected for enrichment analyses using the tool Database for Annotation, Visualization and Integrated Discovery. Protein interaction network analysis was performed for identifying the key genes using STRING and Cytoscape. The correlation of the key genes with overall survival of CRC patients was analyzed. Finally, the key genes were queried against the Drug-Gene Interaction database to find drug candidates for treating CRC.

RESULTS

518 genes associated with intestinal flora were determined by text mining. Based on The Cancer Genome Atlas database, we identified 48 DEGs associated with intestinal flora, including 25 up-regulated and 23 down-regulated DEGs in CRC. The enrichment analyses indicated that the selected genes were mainly involved in cell-cell signaling, immune response, cytokine-cytokine receptor interaction, and JAK-STAT signaling pathway. The protein-protein interaction network was constructed with 13 nodes and 35 edges. Moreover, 8 genes in the significant cluster were considered as the key genes and chemokine (C-X-C motif) ligand 8 (CXCL8) correlated positively with the overall survival of CRC patients. Finally, a total of 24 drugs were predicted as possible drugs for CRC treatment using the Drug-Gene Interaction database.

CONCLUSIONS

These findings of this study may provide new insights into CRC pathogenesis and treatments. The prediction of drug-gene interaction is of great practical significance for exploring new drugs or novel targets for existing drugs.

Interleukin-8: A chemokine at the intersection of cancer plasticity, angiogenesis, and immune suppression

Tumor progression relies on the ability of cancer cells to effectively invade surrounding tissues and propagate. Among the many mechanisms that contribute to tumor progression is the epithelial-to-mesenchymal transition (EMT), a phenotypic plasticity phenomenon that increases the cancer cells' motility and invasiveness and influences their surrounding microenvironment by promoting the secretion of a variety of soluble factors. One such factor is IL-8, a chemokine with multiple pro-tumorigenic roles within the tumor microenvironment (TME), including stimulating proliferation or transformation of tumor cells into a migratory or mesenchymal phenotype. Further, IL-8 can increase tumor angiogenesis or recruit larger numbers of immunosuppressive cells to the tumor. Prognostically, observations in many tumor types show that patients with higher levels of IL-8 at baseline experience worse clinical outcomes. Additionally, studies have shown that the chemokine directly contributes to the development of resistance to both chemotherapy and molecularly targeted agents. More recently, clinical studies evaluating levels of IL-8 in patients receiving immune checkpoint inhibition (ICI) therapy deduced that myeloid tumor infiltration driven by IL-8 contributes to resistance to ICI agents and that peripheral IL-8 can predict outcomes to ICI therapy. Further, pre-clinical data demonstrate that targeting IL-8 or its receptors enables improved tumor killing by immune cells, and treatment strategies combining blockade of the IL-8/IL-8R axis with ICI ultimately improve anti-tumor efficacy. Based on these results and the prognostic capacity of IL-8, there are a number of ongoing clinical trials evaluating the addition of IL-8 targeting strategies to immune-based therapies.

Targeting of BCL-2 Family Members during Anticancer Treatment: A Necessary Compromise between Individual Cell and Ecosystemic Responses?

The imbalance between BCL-2 homologues and pro-death counterparts frequently noted in cancer cells endows them with a cell autonomous survival advantage. To eradicate ectopic cells, inhibitors of these homologues (BH3 mimetics) were developed to trigger, during anticancer treatment, full activation of the canonical mitochondrial apoptotic pathway and related caspases. Despite efficiency in some clinical settings, these compounds do not completely fulfill their initial promise. We herein put forth that a growing body of evidence indicates that mitochondrial integrity, controlled by BCL-2 family proteins, and downstream caspases regulate other cell death modes and influence extracellular signaling by committed cells. Moreover, intercellular communications play a key role in spreading therapeutic response across cancer cell populations and in engaging an immune response. We thus advocate that BH3 mimetics administration would be more efficient in the long term if it did not induce apoptosis in all sensitive cells at the same time, but if it could instead allow (or trigger) death signal production by non-terminally committed dying cell populations. The development of such a trade-off strategy requires to unravel the effects of BH3 mimetics not only on each individual cancer cell but also on homotypic and heterotypic cell interactions in dynamic tumor ecosystems.

The Role of Interleukins in Colorectal Cancer

Despite great progress has been made in treatment strategies, colorectal cancer (CRC) remains the predominant life-threatening malignancy with the feature of high morbidity and mortality. It has been widely acknowledged that the dysfunction of immune system, including aberrantly expressed cytokines, is strongly correlated with the pathogenesis and progression of colorectal cancer. As one of the most well-known cytokines that were discovered centuries ago, interleukins are now uncovering new insights into colorectal cancer therapy. Herein, we divide currently known interleukins into 6 families, including IL-1 family, IL-2 family, IL-6 family, IL-8 family, IL-10 family and IL-17 family. In addition, we comprehensively reviewed the oncogenic or antitumour function of each interleukin involved in CRC pathogenesis and progression by elucidating the underlying mechanisms. Furthermore, by providing interleukins-associated clinical trials, we have further driven the profound prospect of interleukins in the treatment of colorectal cancer.

Enhancing chemosensitivity of wild-type and drug-resistant MDA-MB-231 triple-negative breast cancer cell line to doxorubicin by silencing of STAT 3, Notch-1, and β-catenin genes

BACKGROUND/OBJECTIVE

The absence of receptors in triple-negative breast cancer limits therapeutic choices utilized in clinical management of the disease. Doxorubicin is an important member of therapeutic regimens that is hindered by emergence of resistance. The current work aim to investigate of therapeutic potential of single and combinations of siRNA molecules designed for silencing STAT 3, Notch-1, and β-catenin genes in wild type and doxorubicin resistant MDA-MB-231 triple negative breast cancer cell line.

METHODS

Doxorubicin resistant MDA-MB-231 cell line was developed and characterized for the expression of multidrug resistance-related genes, CD44/CD24 markers, inflammatory cytokines, and the expression of STAT 3, Notch-1, and β-catenin targeted genes. Further, the effect of single and combinations of siRNA on cell viability and chemosensitivity of both wild type MDA-MB-231 cells (MDA-MB-231/WT) and doxorubicin resistant MDA-MB-231 cells (MDA-MB-231/DR₂₅₀) were assessed by MTT assay.

RESULTS

The IC₅₀ of doxorubicin was 10-folds higher in MDA-MB-231/DR₂₅₀ resistant cells compared to MDA-MB-231/WT control cells, 1.53 ± 0.24 μM compared to 0.16 ± 0.02 μM, respectively. The expression of targeted genes was higher in resistant cells compared to control cells, 3.6 ± 0.16 folds increase in β-catenin, 2.7 ± 0.09 folds increase in Notch-1, and 1.8 ± 0.09 folds increase in STAT-3. Following treatment with siRNAs, there was a variable reduction in mRNA expression of each of the targeted genes compared to scrambled siRNA and a reduction in IC₅₀ in both cell lines. The effect of a combination of three genes produced the largest reduction in IC₅₀ in resistant cell line.

CONCLUSION

Our study showed that the silencing of single and multiple genes involved in drug resistance and tumor progression by siRNA can enhance the chemosensitivity of cancer cells to conventional chemotherapy.

Identification of Hub Genes Related to Carcinogenesis and Prognosis in Colorectal Cancer Based on Integrated Bioinformatics

The high mortality of colorectal cancer (CRC) patients and the limitations of conventional tumor-node-metastasis (TNM) stage emphasized the necessity of exploring hub genes closely related to carcinogenesis and prognosis in CRC. The study is aimed at identifying hub genes associated with carcinogenesis and prognosis for CRC. We identified and validated 212 differentially expressed genes (DEGs) from six Gene Expression Omnibus (GEO) datasets and the Cancer Genome Atlas (TCGA) database. We investigated functional enrichment analysis for DEGs. The protein-protein interaction (PPI) network was constructed, and hub modules and genes in CRC carcinogenesis were extracted. A prognostic signature was developed and validated based on Cox proportional hazards regression analysis. The DEGs mainly regulated biological processes covering response to stimulus, metabolic process, and affected molecular functions containing protein binding and catalytic activity. The DEGs played important roles in CRC-related pathways involving in preneoplastic lesions, carcinogenesis, metastasis, and poor prognosis. Hub genes closely related to CRC carcinogenesis were extracted including six genes in model 1 (CXCL1, CXCL3, CXCL8, CXCL11, NMU, and PPBP) and two genes and Metallothioneins (MTs) in model 2 (SLC26A3 and SLC30A10). Among them, CXCL8 was also related to prognosis. An eight-gene signature was proposed comprising AMH, WBSCR28, SFTA2, MYH2, POU4F1, SIX4, PGPEP1L, and PAX5. The study identified hub genes in CRC carcinogenesis and proposed an eight-gene signature with good reproducibility and robustness at the molecular level for CRC, which might provide directive significance for treatment selection and survival prediction.

Tumour Cell Secretome in Chemoresistance and Tumour Recurrence

Chemoresistance is a major factor driving tumour relapse and the high rates of cancer-related deaths. Understanding how cancer cells overcome chemotherapy-induced cell death is critical in promoting patient survival. One emerging mechanism of chemoresistance is the tumour cell secretome (TCS), an array of protumorigenic factors released by tumour cells. Chemotherapy exposure can also alter the composition of the TCS, known as therapy-induced TCS, and can promote tumour relapse and the formation of an immunosuppressive tumour microenvironment (TME). Here, we outline how the TCS can protect cancer cells from chemotherapy-induced cell death. We also highlight recent evidence describing how therapy-induced TCS can impact cancer stem cell (CSC) expansion and tumour-associated immune cells to enable tumour regrowth and antitumour immunity.

Natural products as multidrug resistance modulators in cancer

Cancer is a prominent cause of death globally. Currently, many drugs that are in clinical practice are having a high prevalence of side effect and multidrug resistance. Risk of tumors acquiring resistance to chemotherapy (multidrug resistance) remains a significant hurdle to the successful treatment of various types of cancer. Membrane-embedded drug transporters, generally overexpressed in cancer, are the leading cause among multiple mechanisms of multidrug resistance (MDR). P-glycoprotein (P-gp) also MDR1/ABCB1, multidrug resistance associated protein 1 (MRP1/ABCC1), MRP2 and breast cancer resistance protein (BCRP/ABCG2) are considered to be a prime factor for induction of MDR. To date, several chemical substances have been tested in a number of clinical trials for their MDR modulatory activity which are not having devoid of any side effects that necessitates to find newer and safer way to tackle the current problem of multidrug resistance in cancer. The present study systematically discusses the various classes of natural products i.e flavonoids, alkaloids, terpenoids, coumarins (from plants, marine, and microorganisms) as potential MDR modulators and/or as a source of promising lead compounds. Recently a bisbenzyl isoquinoline alkaloid namely tetrandrine, isolated from Chinese herb Stephania tetrandra (Han-Fang-Chi) is in clinical trials for its MDR reversal activity.

Forkhead box O3 promotes colon cancer proliferation and drug resistance by activating MDR1 expression

BACKGROUND

Globally, colon cancer (CC) is the third reason of tumor-related deaths. Previous reports indicate that Forkhead box O3 (FOXO3) is involved in the development of various tumors and may have different effects depending upon the types of tumors. Hence, this study was to examine the effects of FOXO3 on CC cells and uncover the possible mechanisms.

METHODS

MTT and cell count assay were applied to analyze the viability of transfected CC cells. rVista, dual luciferase reporter assay, and chromatin immunoprecipitation assay were used to identify the downstream target of FOXO3 in HCT116 cells. The mRNA and protein abundance of FOXO3 and MDR1 were determined by quantitative PCR and Western blot, respectively.

RESULTS

Forkhead box O3 stimulated the proliferation of both HCT116 and DLD1 cells. Moreover, FOXO3 overexpression inhibited doxorubicin sensitivity of HCT116 cells, while the knockout of FOXO3 by FOXO3 shRNA restored the doxorubicin sensitivity in doxorubicin-resistant HCT116 DR cells. Next, we found that FOXO3 directly bound to the promoter of MDR1 and enhanced MDR1 expression in HCT116 cells. MDR1 overexpression enhanced the viability and doxorubicin resistance of CC cells. Besides, MDR1 overexpression plasmid significantly abrogated the decrease in cell proliferation and resistance of HCT116 cells to doxorubicin caused by FOXO3 knockout.

CONCLUSION

Forkhead box O3 exhibited promotive effects on the proliferation and doxorubicin resistance in CC cells via targeting MDR1.

Histone deacetylase 6 regulated expression of IL-8 is involved in the doxorubicin (Dox) resistance of osteosarcoma cells via modulating ABCB1 transcription

Emerging evidence shows that cytokines such as interleukins (ILs) are involved in the progression and chemoresistance of multiple tumors, including osteosarcoma (OS). Our present study established the doxorubicin (Dox) resistant human OS MG-63 and HOS cells and named them MG-63/Dox and HOS/Dox, respectively. The expression of IL-8, while not VEGFA, IL-32, or IL-34, was significantly increased in OS/Dox cells as compared with that in the parental cells. IL-8 neutralization antibody can significantly increase the Dox sensitivity of OS/Dox cells. Further, IL-8 can up regulate ABCB1, which encodes one important ATP-binding cassette (ABC) transporter /P-glycoprotein (P-gp). Mechanically, IL-8 increased the transcription of ABCB1 via up regulating its promoter activity, while had no effect on its protein or mRNA stability. Targeted inhibition of p65 can attenuate IL-8 induced transcription of ABCB1 in OS cells. Treatment OS cells with 5-aza-dC, the inhibitor of DNMT, had no effect on expression of IL-8. Expression of HDAC6 in MG-63/Dox and HOS/Dox cells was significantly greater than that in their parental cells. Knockdown of HDAC6 can suppress the expression of IL-8 in OS cells. Collectively, our data showed that HDAC6 mediated upregulation of IL-8 can regulate the Dox sensitivity of OS cells via transcriptionally regulating the expression of ABCB1. Targeted inhibition of IL-8 might be a potent potential approach for overcome the Dox resistance of OS cells and helpful for clinical therapy of OS patients.