Interleukin-8 is related to poor chemotherapeutic response and tumourigenicity in hepatocellular carcinoma

Unveiling the mechanisms and challenges of cancer drug resistance

Cancer treatment faces many hurdles and resistance is one among them. Anti-cancer treatment strategies are evolving due to innate and acquired resistance capacity, governed by genetic, epigenetic, proteomic, metabolic, or microenvironmental cues that ultimately enable selected cancer cells to survive and progress under unfavorable conditions. Although the mechanism of drug resistance is being widely studied to generate new target-based drugs with better potency than existing ones. However, due to the broader flexibility in acquired drug resistance, advanced therapeutic options with better efficacy need to be explored. Combination therapy is an alternative with a better success rate though the risk of amplified side effects is commonplace. Moreover, recent groundbreaking precision immune therapy is one of the ways to overcome drug resistance and has revolutionized anticancer therapy to a greater extent with the only limitation of being individual-specific and needs further attention. This review will focus on the challenges and strategies opted by cancer cells to withstand the current therapies at the molecular level and also highlights the emerging therapeutic options -like immunological, and stem cell-based options that may prove to have better potential to challenge the existing problem of therapy resistance. Video Abstract.

IL-8 from CD248-expressing cancer-associated fibroblasts generates cisplatin resistance in non-small cell lung cancer

Chemotherapy-resistant non-small cell lung cancer (NSCLC) presents a substantial barrier to effective care. It is still unclear how cancer-associated fibroblasts (CAFs) contribute to NSCLC resistance to chemotherapy. Here, we found that CD248+ CAFs released IL-8 in NSCLC, which, in turn, enhanced the cisplatin (CDDP) IC50 in A549 and NCI-H460 while decreasing the apoptotic percentage of A549 and NCI-H460 in vitro. The CD248+ CAFs-based IL-8 secretion induced NSCLC chemoresistance by stimulating nuclear factor kappa B (NF-κB) and elevating ATP-binding cassette transporter B1 (ABCB1). We also revealed that the CD248+ CAFs-based IL-8 release enhanced cisplatin chemoresistance in NSCLC mouse models in vivo. Relative to wild-type control mice, the CD248 conditional knockout mice exhibited significant reduction of IL-8 secretion, which, in turn, enhanced the therapeutic efficacy of cisplatin in vivo. In summary, our study identified CD248 activates the NF-κB axis, which, consecutively induces the CAFs-based secretion of IL-8, which promotes NSCLC chemoresistance. This report highlights a potential new approach to enhancing the chemotherapeutic potential of NSCLC-treating cisplatin.

Prostate cancer cell-derived exosomal IL-8 fosters immune evasion by disturbing glucolipid metabolism of CD8+ T cell

Depletion of CD8+ T cells is a major obstacle in immunotherapy; however, the relevant mechanisms remain largely unknown. Here, we showed that prostate cancer (PCa) cell-derived exosomes hamper CD8+ T cell function by transporting interleukin-8 (IL-8). Compared to the low IL-8 levels detected in immune cells, PCa cells secreted the abundance of IL-8 and further accumulated in exosomes. The delivery of PCa cell-derived exosomes into CD8+ T cells exhausted the cells through enhanced starvation. Mechanistically, exosomal IL-8 overactivated PPARα in recipient cells, thereby decreasing glucose utilization by downregulating GLUT1 and HK2 but increasing fatty acid catabolism via upregulation of CPT1A and ACOX1. PPARα further activates uncoupling protein 1 (UCP1), leading to fatty acid catabolism for thermogenesis rather than ATP synthesis. Consequently, inhibition of PPARα and UCP1 restores CD8+ T cell proliferation by counteracting the effect of exosomal IL-8. This study revealed that the tumor exosome-activated IL-8-PPARα-UCP1 axis harms tumor-infiltrating CD8+ T cells by interfering with energy metabolism.

Melatonin blunts the tumor-promoting effect of cancer-associated fibroblasts by reducing IL-8 expression and reversing epithelial-mesenchymal transition

BACKGROUND

Most studies on melatonin have focused on tumor cells but have ignored the tumor microenvironment (TME), especially one of its important components, the cancer-associated fibroblasts (CAFs). Therefore, we attempted to explore the role of melatonin in TME.

METHODS

We investigated the regulatory role of melatonin in the tumor-promoting effect of CAFs and its underlying mechanism by using cell and animal models.

RESULTS

CAFs promoted tumor progression, but melatonin weakened the tumor-promoting effect of CAFs. Compared with tumor cells, IL-8 was mainly expressed in CAFs. CAFs-overexpressing IL-8 induced the epithelial-mesenchymal transition (EMT) of tumor cells, and a positive crosstalk was observed between CAFs and tumor cells undergoing EMT, thereby further promoting the IL-8 expression. Melatonin suppressed this crosstalk by inhibiting the NF-κB pathway, thereby impeding the IL-8 expression from CAFs. Importantly, melatonin reversed CAFs-derived IL-8-mediated EMT by inhibiting the AKT pathway. Melatonin was found to directly and indirectly inhibit tumor progression.

CONCLUSION

Our research reveals the potential action mechanism of melatonin in regulating the CAF-tumor cell interaction and suggests the potential of melatonin as an adjuvant of tumor therapy.

Regulation of Tumor and Metastasis Initiation by Chemokine Receptors

Tumor-initiating cells (TICs) are a rare sub-population of cells within the bulk of a tumor that are major contributors to tumor initiation, metastasis, and chemoresistance. TICs have a stem-cell-like phenotype that is dictated by the expression of master regulator transcription factors, including OCT4, NANOG, and SOX2. These transcription factors are expressed via activation of multiple signaling pathways that drive cancer initiation and progression. Importantly, these same signaling pathways can be activated by select chemokine receptors. Chemokine receptors are increasingly being revealed as major drivers of the TIC phenotype, as their signaling can lead to activation of stemness-controlling transcription factors. Additionally, the cell surface expression of chemokine receptors provides a unique therapeutic target to disrupt signaling pathways that control the expression of master regulator transcription factors and the TIC phenotype. This review summarizes the master regulator transcription factors known to dictate the TIC phenotype, along with the complex signaling pathways that can mediate their expression and the chemokine receptors that are most upstream of this phenotype.

Doxorubicin-induced senescence promotes stemness and tumorigenicity in EpCAM-/CD133- nonstem cell population in hepatocellular carcinoma cell line, HuH-7

The therapeutic induction of senescence is a potential means to treat cancer, primarily acting through the induction of a persistent growth‐arrested state in tumors. However, recent studies have indicated that therapy‐induced senescence (TIS) in tumor cells allows for the prolonged survival of a subgroup of cells in a dormant state, with the potential to re‐enter the cell cycle along with an increased stemness gene expression. Residual cells after TIS with increased cancer stem cell phenotype may have profound implications for tumor aggressiveness and disease recurrence. Herein, we investigated senescence‐associated stemness in EpCAM+/CD133+ liver cancer stem cell and EpCAM−/CD133− nonstem cell populations in HuH7 cell line. We demonstrated that treatment with doxorubicin induces senescence in both cell populations, accompanied by a significant increase in the expression of reprogramming genes SOX2, KLF4, and c‐MYC as well as liver stemness‐related genes EpCAM, CK19, and ANXA3 and the multidrug resistance‐related gene ABCG2. Moreover, doxorubicin treatment significantly increased EpCAM + population in nonstem cells indicating senescence‐associated reprogramming of nonstem cell population. Also, Wnt/β‐catenin target genes were increased in these cells, while inhibition of this signaling pathway decreased stem cell gene expression. Importantly, Dox‐treated EpCAM−/CD133− nonstem cells had increased in vivo tumor‐forming ability. In addition, when SASP‐CM from Dox‐treated cells were applied onto hİPSC‐derived hepatocytes, senescence was induced in hepatocytes along with an increased expression of TGF‐β, KLF4, and AXIN2. Importantly, SASP‐CM was not able to induce senescence in Hep3B‐TR cells, a derivative line rendered resistant to TGF‐β signaling. Furthermore, ELISA experiments revealed that the SASP‐CM of Dox‐treated cells contain inflammatory cytokines IL8 and IP10. In summary, our findings further emphasize the importance of carefully dissecting the beneficial and detrimental aspects of prosenescence therapy in HCC and support the potential use of senolytic drugs in HCC treatment in order to eliminate adverse effects of TIS.

Targeting Liver Cancer Stem Cells: An Alternative Therapeutic Approach for Liver Cancer

The first report of cancer stem cell (CSC) from Bruce et al. has demonstrated the relatively rare population of stem-like cells in acute myeloid leukemia (AML). The discovery of leukemic CSCs prompted further identification of CSCs in multiple types of solid tumor. Recently, extensive research has attempted to identity CSCs in multiple types of solid tumors in the brain, colon, head and neck, liver, and lung. Based on these studies, we hypothesize that the initiation and progression of most malignant tumors rely largely on the CSC population. Recent studies indicated that stem cell-related markers or signaling pathways, such as aldehyde dehydrogenase (ALDH), CD133, epithelial cell adhesion molecule (EpCAM), Wnt/β-catenin signaling, and Notch signaling, contribute to the initiation and progression of various liver cancer types. Importantly, CSCs are markedly resistant to conventional therapeutic approaches and current targeted therapeutics. Therefore, it is believed that selectively targeting specific markers and/or signaling pathways of hepatic CSCs is an effective therapeutic strategy for treating chemotherapy-resistant liver cancer. Here, we provide an overview of the current knowledge on the hepatic CSC hypothesis and discuss the specific surface markers and critical signaling pathways involved in the development and maintenance of hepatic CSC subpopulations.

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.

Cancer stemness in hepatocellular carcinoma: mechanisms and translational potential

Cancer stemness, referring to the stem-cell-like phenotype of cancer cells, has been recognised to play important roles in different aspects of hepatocarcinogenesis. A number of well-established cell-surface markers already exist for liver cancer stem cells, with potential new markers of liver cancer stem cells being identified. Both genetic and epigenetic factors that affect various signalling pathways are known to contribute to cancer stemness. In addition, the tumour microenvironment—both physical and cellular—is known to play an important role in regulating cancer stemness, and the potential interaction between cancer stem cells and their microenvironment has provided insight into the regulation of the tumour-initiating ability as well as the cellular plasticity of liver CSCs. Potential specific therapeutic targeting of liver cancer stemness is also discussed. With increased knowledge, effective druggable targets might be identified, with the aim of improving treatment outcome by reducing chemoresistance.

Interleukin-8 associated with chemosensitivity and poor chemotherapeutic response to gastric cancer

Background

Gastric cancer (GC) patients have been found to have developed chemotherapy resistance that has resulted in a lowering of their overall survival rates. Interleukin-6 (IL-6) and interleukin-8 (IL-8) could be responsible as the predictive biomarkers in monitoring drug resistance. We have developed a protocol to monitor drug treatment by testing ex vivo chemosensitivity and cytokine levels of primary gastric cultures obtained from endoscopic biopsies.

Methods

We studied 49 patients with distal GC who underwent primary surgical resection between June 2014 and December 2016 in the northern endemic region of Thailand. The clinical and pathological data of patients were recorded, and the cancer sub-type was classified. The correlation of cytokine IL-6 and IL-8 protein expression levels and chemotherapy sensitivity in primary gastric cultures was investigated. Endoscopic biopsies were collected before and/or after chemotherapy treatment followed by FOLFOXIV regimen (oxaliplatin + 5-FU/leucovorin). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to examine ex vivo chemosensitivity to cisplatin, oxaliplatin, 5-fluorouracil (5-FU) and irinotecan. Enzyme-linked immunosorbent assay (ELISA) was performed to investigate cytokine levels.

Results

Ex vivo drug treatment of 49 primary gastric cultures from naive patients revealed a significant correlation between basal levels of IL-8 and chemosensitivity to cisplatin (P=0.001) and oxaliplatin (P=0.001). IL-8 protein expression levels were significantly decreased in the early phase after cisplatin and oxaliplatin treatments leading to an increase in cell sensitivity to drug treatments. Among 49 patients, 11 patients were classified as partial or poor responders after drug interventions, in which case, second endoscopic biopsies were performed for determination of chemosensitivity and cytokine levels. The results demonstrated significant decreases in sensitivity to cisplatin (P=0.049) and oxaliplatin (P=0.014), meanwhile IL-8 protein expression levels were significantly increased by P=0.0423 in both drug treatments. There was no correlation of IL-6 and drug resistance when treatments of the primary gastric cultures involved each of the four chemotherapeutic drugs (P=0.0663).

Conclusions

Upregulation of IL-8 after drug intervention might be useful as predictive biomarker in monitoring drug resistance in GC patients; however, this needs to be confirmed among a larger number of patients and with control groups that are properly age-paired. The established primary gastric culture could serve as a valuable tool for chemotherapy screening, while the repeated usage of platinum drugs may result in drug resistance via upregulation of IL-8 levels.

Targeting PI3K/Akt/mTOR Pathway Identifies Differential Expression and Functional Role of IL8 in Liver Cancer Stem Cell Enrichment

Activation of the PI3K/Akt/mTOR pathway is an important signaling mechanism involved in the development and the progression of liver cancer stem cell (LCSC) population during acquired Sorafenib resistance in advanced hepatocellular carcinoma (HCC). Therefore, identification of novel therapeutic targets involving this pathway and acting on LCSCs is highly essential. Here, we analyzed the bioactivities and the molecular pathways involved in the action of small-molecule PI3K/Akt/mTOR pathway inhibitors in comparison with Sorafenib, DNA intercalators, and DAPT (CSC inhibitor) on CD133/EpCAM-positive LCSCs. Sorafenib and DNA intercalators lead to the enrichment of LCSCs, whereas Rapamycin and DAPT significantly reduced CD133/EpCAM positivity. Sequential treatment with Rapamycin followed by Sorafenib decreased the ratio of LCSCs as well as their sphere formation capacity, as opposed to Sorafenib alone. Under the stress of the inhibitors, differential expression analysis of 770 cancer pathway genes using network-based systems biology approach singled out IL8 expression association with LCSCs. Furthermore, IL8 secretion and LCSC enrichment ratio was also positively correlated. Following IL8 inhibition with its receptor inhibitor Reparixin or siRNA knockdown, LCSC features of HCC cells were repressed, and sensitivity of cells to Sorafenib increased significantly. Furthermore, inflammatory cytokines (IL8, IL1β, and IL11) were also upregulated upon treatment with HCC-approved kinase inhibitors Sorafenib and Regorafenib. Hence, chemotherapeutic stress alters inflammatory cytokine gene expression in favor of hepatic CSC population survival. Autocrine IL8 signaling is identified as a critical event, and its inhibition provides a promising complimentary therapeutic approach for the prevention of LCSC population enrichment.

A systematic review and meta-analysis of evaluation of serum interleukin 8 levels in hepatocellular carcinoma

Aim of the study

To estimate serum interleukin 8 (IL-8) level in patients with hepatocellular carcinoma (HCC) compared to controls and patients with chronic hepatitis (CH) and liver cirrhosis (LC).

Material and methods

Three databases, i.e. PubMed, Web of Science, and Scopus, were searched up to November 2017 without language restriction. The mean difference (MD) and 95% confidence interval (CI) were used by a random-effects analysis in RevMan version 5.3, and sensitivity analysis was performed as the secondary analysis.

Results

Out of 239 studies found, 10 studies recruiting 659 HCC patients, 237 controls, 357 patients with LC, and 48 patients with CH were included and analyzed in the meta-analysis. The pooled MDs were 39.48 (95%CI: 152.31, 406.47, p < 0.00001), 21.32 (95% CI: –6.04, 48.68, p = 0.13), and 36.46 (95% CI: 21.77, 51.15, p < 0.00001) in the patients with HCC compared to the controls, the patients with LC and those with CH, respectively.

Conclusions

An elevated serum IL-8 level in the HCC patients compared to the three other groups showed an increased risk for this cytokine in HCC patients. Therefore, this interleukin can be used as a new biomarker replacing alpha-fetoprotein (AFP) or as a clinical assay for evaluation of the pathogenesis and probably the progression or development of HCC.

IL-8 and CXCR1 expression is associated with cancer stem cell-like properties of clear cell renal cancer

Recent studies suggest that clear cell renal cell carcinoma (ccRCC) possesses a rare population of cancer stem cells (CSCs) that might contribute to tumor heterogeneity, metastasis and therapeutic resistance. Nevertheless, their relevance for renal cancer is still unclear. In this study, we successfully isolated CSCs from established human ccRCC cell lines. CSCs displayed high expression of the chemokine IL‐8 and its receptor CXCR1. While recombinant IL‐8 significantly increased CSC number and properties in vitro, CXCR1 inhibition using an anti‐CXCR1 antibody or repertaxin significantly reduced these features. After injection into immune‐deficient mice, CSCs formed primary tumors that metastasized to the lung and liver. All xenografted tumors in mice expressed high levels of IL‐8 and CXCR1. Furthermore, IL‐8/CXCR1 expression significantly correlated with decreased overall survival in ccRCC patients. These results suggest that the IL‐8/CXCR1 phenotype is associated with CSC‐like properties in renal cancer. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Macrophage-derived CCL22 promotes an immunosuppressive tumor microenvironment via IL-8 in malignant pleural effusion

Immune dysfunction often occurs in malignant pleural effusion (MPE). In our previous study, TGF-β derived predominantly from macrophages plays an important role in impairing T cell cytotoxicity in MPE. Therefore, we aimed to investigate whether other immunoregulatory cells and factors mediated TGF-β secretion from macrophages, involved in the immunosuppressive microenvironment of MPE, and to provide clues for potential immune therapy for MPE as well. We found that CCL22 level in MPE was significantly higher than that in non-malignant pleural effusion. The high level of CCL22 was closely associated with poor survival in MPE patients with lung cancer. CCL22 was dominantly produced by tumor-associated macrophages (TAMs) in MPE. Meanwhile, TAM-derived TGF-β mediated CCL22 expression in TAMs via c-Fos. CCL22 promoted the recruitment of regulatory T cells (Tregs) in MPE. Lastly, Treg-secreted high level of IL-8 further induced TGF-β production from TAMs, and promoted the immunosuppressive tumor microenvironment in MPE. Our results indicate that macrophage-derived CCL22 plays an important role in the immunosuppressive tumor microenvironment via IL-8 in MPE.

8-bromo-7-methoxychrysin suppress stemness of SMMC-7721 cells induced by co-culture of liver cancer stem-like cells with hepatic stellate cells

BACKGROUND

Our previous works have demonstrated that 8-bromo-7-methoxychrysin suppressed stemness of human hepatocellular carcinoma (HCC) cell line SMMC-7721 induced by condition medium from hepatic stellate cell line LX-2 that was activated by liver cancer stem-like cells (LCSCs). However, whether and whereby BrMC inhibits the stemness induced by co-culture of LCSCs and LX-2 cells remains to be investigated.

METHODS

The second-generation spheres by sphere culture were identified and used as SMMC-7721-and MHCC97H-derived LCSLCs. SMMC-7721-and MHCC97-derived LCSCs/LX-2 cells transwell co-culture system was treated with BrMC and its lead compound chrysin. The concentrations of IL-6, IL-8, HGF and PDGF in condition medium from co-culture were measured by enzyme-linked immunosorbent assay (ELISA). The stemness of SMMC-7721 cells was evaluated by sphere formation assay and western blot analysis for expression levels of cancer stem cell markers (CD133 and CD44).The expression levels of cancer-associated fibroblast markers (FAP-α and α-SMA) were employed to evaluate pathologic activation of LX-2 cells. Addition of IL-6 and/or HGF or deletion of IL-6 and/or HGF was conducted to investigate the mechanisms for BrMC and chrysin treatment in SMMC-7721-derived LCSLCs co-cultured with LX-2cells.

RESULTS

The co-culture of LCSLCs with LX-2 cells increased sphere formation capability as well as expression of CD133 and CD44 in SMMC-7721 cells, meanwhile, upregulated expression of FAP-α in LX-2 cells. ELISA indicated that the concentrations of IL-6 and HGF were significantly elevated in Co-CM than that of condition media from co-cultured SMMC-7721 cells/LX-2 cells. Treatment of BrMC and chrysin with co-cultures of SMMC-7721- and MHCC97H-derived LCSLCs and LX-2 cells effectively inhibited the above responses. Moreover, addition of IL-6 and/or HGF induced stemness of SMMC-7721 cells and activation of LX-2 cells, conversely, deletion of IL-6 and/or HGF suppressed those. Furthermore, the inhibitory effects of BrMC and chrysin on stemness of SMMC-7721 cells and activation of LX-2 cells were attenuated by addition of IL-6 or HGF, and enhanced by deletion of IL-6 or HGF.

CONCLUSIONS

Our results suggest IL-6 and HGF may be the key communication molecules for the interaction between LCSLCs and HSCs, and BrMC and chrysin could block these effects and be the novel therapeutic candidates for HCC management.

Activated and Exhausted MAIT Cells Foster Disease Progression and Indicate Poor Outcome in Hepatocellular Carcinoma

PURPOSE

Innate immunity is an indispensable arm of tumor immune surveillance, and the liver is an organ with a predominance of innate immunity, where mucosal-associated invariant T (MAIT) cells are enriched. However, little is known about the phenotype, functions, and immunomodulatory role of MAIT cells in hepatocellular carcinoma (HCC).Experimental Design: The distribution, phenotype, and function of MAIT cells in patients with HCC were evaluated by both flow cytometry (FCM) and in vitro bioassays. Transcriptomic analysis of MAIT cells was also performed. Prognostic significance of tumor-infiltrating MAIT cells was validated in four independent cohorts of patients with HCC.

RESULTS

Despite their fewer densities in HCC tumor than normal liver, MAIT cells were significantly enriched in the HCC microenvironment compared with other mucosa-associated organs. Tumor-derived MAIT cells displayed a typical CCR7^-CD45RA^-CD45RO⁺CD95⁺ effector memory phenotype with lower costimulatory and effector capabilities. Tumor-educated MAIT cells significantly upregulated inhibitory molecules like PD-1, CTLA-4, TIM-3, secreted significantly less IFNγ and IL17, and produced minimal granzyme B and perforin while shifting to produce tumor-promoting cytokines like IL8. Transcriptome sequencing confirmed that tumor-derived MAIT cells were reprogrammed toward a tumor-promoting direction by downregulating genes enriched in pathways of cytokine secretion and cytolysis effector function like NFKB1 and STAT5B and by upregulating genes like IL8, CXCL12, and HAVCR2 (TIM-3). High infiltration of MAIT cells in HCC significantly correlated with an unfavorable clinical outcome, revealed by FCM, qRT-PCR, and multiplex IHC analyses, respectively.

CONCLUSIONS

HCC-infiltrating MAIT cells were functionally impaired and even reprogrammed to shift away from antitumor immunity and toward a tumor-promoting direction.See related commentary by Carbone, p. 3199.

Chitosan-coated liposomes loaded with butyric acid demonstrate anticancer and anti-inflammatory activity in human hepatoma HepG2 cells

Butyric acid (BA) has been reported to induce anticancer effects on hepatocellular carcinoma (HCC) cells both in vitro and in vivo. However, its delivery and release in cancer tissues must be optimized. On the basis of these requirements, we prepared liposomes coated with chitosan and uncoated liposomes and both types were loaded with BA through a thin-film hydration method. The liposomes coated or uncoated with chitosan had a mean hydrodynamic size of 83.5 and 110.3 nm, respectively, with a homogeneous size distribution of the particles. For evaluation of the biological effects of the nanoformulations, the hepatoblastoma (HB) HepG2 cell line was utilized. BA-loaded liposomes coated with chitosan showed a considerable higher cytotoxicity than both uncoated liposomes and free BA, with IC50 values, after 72 h of incubation, of 7.5, 2.5 and 1.6 mM, respectively. Treatment of HepG2 cells for 5 h with the BA-loaded liposomes coated with chitosan at 5 mM lowered the extent of the increase in IL-8, IL-6, TNF-α and TGF-β expression of approximately 64, 58, 85 and 73.8%, respectively, when compared to the untreated cells. The BA-loaded liposomes coated with chitosan had marked capacity to be internalized in human HB cells showing an increased cytotoxic activity when compared with free BA and important anti-inflammatory effects by inhibiting production of cytokines with a central role in liver cell survival.

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

Cytokines play important roles in tumorigenesis and progression of cancer cells, while their functions in drug resistance remain to be illustrated. We successfully generated doxorubicin (Dox)-resistant CRC HCT-116 and SW480 cells (namely HCT-116/Dox and SW480/Dox, respectively). Cytokine expression analysis revealed that IL-8, while not FGF-2, EGF, TGF-β, IL-6, or IL-10, was significantly increased in Dox-resistant CRC cells as compared with their corresponding parental cells. Targeted inhibition of IL-8 via siRNAs or its inhibitor reparixin can increase the Dox sensitivity of HCT-116/Dox and SW480/Dox cells. The si-IL-8 can decrease the mRNA and protein expression of multidrug resistance 1 (MDR1, encoded by ABCB1), while has no effect on the expression of multidrug resistance-associated protein 1 (ABCC1), in CRC Dox-resistant cells. IL-8 can increase the phosphorylation of p65 and then upregulate the binding between p65 and promoter of ABCB1. BAY 11-7082, the inhibitor of NF-κB, suppressed the recombination IL-8 (rIL-8) induced upregulation of ABCB1. It confirmed that NF-κB is involved in IL-8-induced upregulation of ABCB1. rIL-8 also increased the phosphorylation of IKK-β, which can further activate NF-κB, while specific inhibitor of IKK-β (ACHP) can reverse rIL-8-induced phosphorylation of p65 and upregulation of MDR1. These results suggested that IL-8 regulates the Dox resistance of CRC cells via modulation of MDR1 through IKK-β/p65 signals. The targeted inhibition of IL-8 might be an important potential approach to overcome the clinical Dox resistance in CRC patients.

Cytokine-mediated therapeutic resistance in breast cancer

Therapeutic resistance leading to tumor relapse is a major challenge in breast cancer (BCa) treatment. Numerous factors involved in multiple mechanisms promote the development of tumor chemo/radio-resistance. Cytokines/chemokines are important inflammatory factors and highly related to tumorigenesis, metastasis and tumors responses to treatment. A large number of studies have demonstrated that the network of cytokines activates multiple cell signaling pathways to promote tumor cell survival, proliferation, invasion, and migration. Particularly in BCa, cytokines-enhanced the epithelial-mesenchymal transition (EMT) process plays a pivotal role in the progression of metastatic phenotypes and resistance to the traditional chemo/radio-therapy. Virtually, therapeutic resistance is not entirely determined by tumor cell intrinsic characteristics but also dependent upon synchronized effects by numerous of local microenvironmental factors. Emerging evidence highlighted that exosomes secreted from various types of cells promote intercellular communication by transferring bioactive molecules including miRNAs and cytokines, suggesting that exosomes are essential for sustentation of tumor progression and therapeutic resistance within the tumor microenvironment. In this review, we discuss the mechanisms by which cytokines promote therapeutic resistance of BCa and suggest a potential approach for improving BCa therapeutics by inhibition of exosome function.

HSP90 inhibition alters the chemotherapy-driven rearrangement of the oncogenic secretome

Adaptive resistance to therapy is a hallmark of cancer progression. To date, it is not entirely clear how microenvironmental stimuli would mediate emergence of therapy-resistant cell subpopulations, although a rearrangement of the cancer cell secretome following therapy-induced stress can be pivotal for such a process. Here, by using the highly chemoresistant malignant pleural mesothelioma (MPM) as an experimental model, we unveiled a key contribution of the chaperone HSP90 at assisting a chemotherapy-instigated Senescence-Associated-Secretory-Phenotype (SASP). Thus, administration of a clinical trial grade, HSP90, inhibitor blunted the release of several cytokines by the chemotherapy-treated MPM cells, including interleukin (IL)-8. Reduction of IL-8 levels hampered the FAK-AKT signaling and inhibited 3D growth and migration. This correlated with downregulation of key EMT and chemoresistance genes and affected the survival of chemoresistant ALDH^bright cell subpopulations. Altogether, inhibition of HSP90 provoked a switch from a pro-tumorigenic SASP to a pro-apoptotic senescence status, thus resulting in chemosensitizing effects. In mouse xenografts treated with first-line agents, inhibiting HSP90 blunted FAK activation and reduced the expression of ALDH1A3 and the levels of circulating human IL-8, these latter strongly correlating with the effect on tumor growth. We validated the above findings in primary mesothelioma cultures, a more clinically relevant model. We unveiled here a key contribution of the chaperone HSP90 at assisting the secretory stress in chemotherapy-treated cells, which may warrant further investigation in combinatorial therapeutic settings.

CCAR2 negatively regulates IL-8 production in cervical cancer cells

Cell cycle and apoptosis regulator 2 (CCAR2) is a multifaceted protein that controls diverse cellular functions; however, its function in cancer is unclear. To better understand its potential role in cancer, we examined gene expression patterns regulated by CCAR2 in cervical cancer cells. Cytokine and chemokine production by CCAR2-deficient cells increased under oxidative conditions. In particular, H₂O₂-treated CCAR2-depleted cells showed a significant increase in interleukin-8 (IL-8) production, indicating a negative regulation of IL-8 by CCAR2. Upregulation of IL-8 expression in CCAR2-deficient cells occurred via activation of transcription factor AP-1. The negative correlation between CCAR2 and IL-8 expression was confirmed by examining mRNA and protein levels in tissues from cervical cancer patients. Furthermore, CCAR2-regulated IL-8 expression is associated with a shorter survival of cervical cancer patients. Overall, the data suggest that CCAR2 plays a critical role in controlling both the cancer secretome and cancer progression.

Cancer vaccines and immunotherapeutic approaches in hepatobiliary and pancreatic cancers

Hepatobiliary and pancreatic cancers along with other gastrointestinal malignancies remain the leading cause of cancer-related deaths worldwide. Strategies developed in the recent years on immunotherapy and cancer vaccines in the setting of primary liver cancer as well as in pancreatic cancer are the scope of this review. Significance of orthotopic and autochthonous animal models which mimic and/or closely reflect human malignancies allowing for a prompt and trustworthy analysis of new therapeutics is underlined. Combinational approaches that on one hand, specifically target a defined cancer-driving pathway, and on the other hand, restore the functions of immune cells, which effector functions are often suppressed by a tumor milieu, are shown to have the strongest perspectives and future directions. Among combinational immunotherapeutic approaches a personalized- and individual cancer case-based therapy is of special importance.

Involvement of soluble B7-H3 in combination with the serum inflammatory cytokines interleukin-17, -8 and -6 in the diagnosis of hepatocellular carcinoma

Previous studies have demonstrated that B7-H3, and the inflammatory cytokines interleukin (IL)-17, IL-8 and IL-6, are involved in the development of a variety of tumors. The objectives of the present study were: i) To investigate the association between soluble B7-H3 (sB7-H3) and cytokine levels of IL-17, IL-8 and IL-6 in the serum of patients with hepatocellular carcinoma (HCC); and ii) to determine their potential value for use in HCC diagnosis. Serum sB7-H3, IL-17, IL-8 and IL-6 levels in the HCC patients and healthy control subjects were measured using ELISA. The accuracy of each of these biomarkers in HCC diagnosis was compared using a receiver operating characteristic curve and the area under the curve (AUC). A logistic regression model was used to investigate the accuracy of diagnosing HCC when evaluated using combined determinations of sB7-H3, IL-17, IL-8 and IL-6 levels. The data demonstrated that serum levels of sB7-H3, IL-17, IL-8 and IL-6 were significantly increased in HCC patients compared with those in the healthy control group. Serum sB7-H3 levels were positively associated with serum IL-17, whereas serum IL-8 levels were negatively correlated with serum IL-17 levels. The AUC values for sB7-H3, IL-17, IL-8 and IL-6 were 83.2, 65.7, 95.3 and 97.0%, respectively, and indicated that all four biomarkers exhibited a statistically significant capacity for diagnosing HCC. Using the logistic regression model, the AUC value, sensitivity and specificity, as determined for the combination of the four biomarkers, were 99.2, 96.67 and 97.14%, respectively. This was significantly greater than that achieved when any single biomarker was used alone in the logistic regression model to assess their accuracy in HCC diagnosis. The optimum cutoff value of the predicted probability obtained by the combination of sB7-H3, IL-17, IL-8 and IL-6 in the regression model was 0.5745. To conclude, the present study revealed that there exists a positive association between serum sB7-H3 and IL-17 levels in HCC patients. Determinations involving the combination of serum sB7-H3, IL-17, IL-8 and IL-6 levels demonstrate great potential for use in HCC diagnosis.

Knockdown of HIF-1α and IL-8 induced apoptosis of hepatocellular carcinoma triggers apoptosis of vascular endothelial cells

A local hypoxic microenvironment is one of the most important characteristics of solid tumors. Hypoxia inducible factor-1α (HIF-1α) and Interleukin-8 (IL-8) activate tumor survival from hypoxic-induced apoptosis in each pathway. This study aimed to evaluate whether knockdown of HIF-1α and IL-8 induced apoptosis of the hepatocellular carcinoma (HCC) and endothelial cell lines. HCC cell lines were infected with adenovirus-expressing shRNA for HIF-1α and IL-8 and maintained under hypoxic conditions (1% O2, 24 h). The expression levels of HIF-1α and both apoptotic and growth factors were examined by real-time quantitative PCR and western blot. We also investigated apoptosis by TUNEL assay (FACS and Immunofluorescence) and measured the concentration of cytochrome C. Inhibition of HIF-1α and IL-8 up-regulated the expression of apoptotic factors while downregulating anti-apoptotic factors simultaneously. Knockdown of HIF-1α and IL-8 increased the concentration of cytochrome C and enhanced DNA fragmentation in HCC cell lines. Moreover, culture supernatant collected from the knockdown of HIF-1α and IL-8 in HCC cell lines induced apoptosis in human umbilical vein endothelial cells under hypoxia, and the expression of variable apoptotic ligand increased from HCC cell lines, time-dependently. These data suggest that adenovirus-mediated knockdown of HIF-1α and IL-8 induced apoptosis in HCC cells and triggered apoptosis of vascular endothelial cells.

17β-estradiol exerts anticancer effects in anoikis-resistant hepatocellular carcinoma cell lines by targeting IL-6/STAT3 signaling

17β-Estradiol (E2) has been proven to exert protective effects against HCC; however, its mechanism on HCC proliferation and suppression of invasion remains to be further explored. Because HCC up-regulates serum Interleukin-6 (IL-6) levels and Signal Transducer and Activator of Transcription 3 (STAT3), molecular agents that attenuate IL-6/STAT3 signaling can potentially suppress HCC development. In this study, we examined involvement of E2 in anoikis resistance that induces invasion capacities and chemo-resistance. Huh-BAT and HepG2 cells grown under anchorage-independent condition were selected. The anoikis-resistant (AR) cells showed stronger chemo-resistance against sorafenib, doxorubicin, 5-fluorouracil and cisplatin compared to adherent HCC cells. AR HCC cells exhibited decreased expression of E-cadherin and increased expression of the N-cadherin and vimentin compared to adherent HCC cells. We then demonstrated that E2 suppressed cell proliferation in AR HCC cells. IL-6 treatment enhanced invasive characteristics, and E2 reversed it. Regarding mechanism of E2, it decreased in the phosphorylation of STAT3 that overexpressed on AR HCC cells. The inhibitory effect of E2 on cell growth was accompanied with cell cycle arrest at G2/M phase and caspase-3/9/PARP activation through c-Jun N-terminal Kinase (JNK) phosphorylation. Taken together, these findings suggested that E2 inhibited the proliferation of AR HCC cells through down-regulation of IL-6/STAT3 signaling. Thus, E2 can be a potential therapeutic drug for treatment of metastatic or chemo-resistant HCC.

IL-8 confers resistance to EGFR inhibitors by inducing stem cell properties in lung cancer

Epidermal growth factor receptor (EGFR)-targeted strategy is limited by resistance. We identify the potential genes involved in EGFR TKI (tyrosine kinase inhibitor) resistance and study the therapeutic mechanism in the non-small cell lung cancers. Potential genes involved in resistance were examined by analyzing datasets from a pair of EGFR TKI-sensitive (PC9) and TKI-resistant cells (PC9/gef). Blood specimens from patients taking EGFR TKI as first-line treatment were used to examine the correlation between drug's efficacy and IL-8 level. The effects of IL-8 on gefitinib-induced apoptosis, stemness, and in vivo tumorigenicity were investigated using established cell lines. We identified IL-8 was up-regulated in gefitinib-resistant cells, and high plasma IL-8 level was correlated with shorter progression-free-survival time. IL-8 overexpression suppressed gefitinib-induced apoptosis in gefitinib-sensitive cells. By contrast, suppression of IL-8 enhanced gefitinib-induced cell death in gefitinib-resistant cells. IL-8 also increased stem-like characteristics including aldehyde dehydrogenase activity, expression of stemness-related genes, clonogenic activity, side-population, and in vivo tumorigenicity. Consistently, knockdown of IL-8 leads to loss of stem cell-like characteristics in gefitinib-resistant cells. Our study demonstrates an important role for IL-8, and suggests IL-8 is a potential therapeutic target for overcoming EGFR TKI resistance.

Glioblastoma Stem Cells Microenvironment: The Paracrine Roles of the Niche in Drug and Radioresistance

Among all solid tumors, the high-grade glioma appears to be the most vascularized one. In fact, "microvascular hyperplasia" is a hallmark of GBM. An altered vascular network determines irregular blood flow, so that tumor cells spread rapidly beyond the diffusion distance of oxygen in the tissue, with the consequent formation of hypoxic or anoxic areas, where the bulk of glioblastoma stem cells (GSCs) reside. The response to this event is the induction of angiogenesis, a process mediated by hypoxia inducible factors. However, this new capillary network is not efficient in maintaining a proper oxygen supply to the tumor mass, thereby causing an oxygen gradient within the neoplastic zone. This microenvironment helps GSCs to remain in a "quiescent" state preserving their potential to proliferate and differentiate, thus protecting them by the effects of chemo- and radiotherapy. Recent evidences suggest that responses of glioblastoma to standard therapies are determined by the microenvironment of the niche, where the GSCs reside, allowing a variety of mechanisms that contribute to the chemo- and radioresistance, by preserving GSCs. It is, therefore, crucial to investigate the components/factors of the niche in order to formulate new adjuvant therapies rendering more efficiently the gold standard therapies for this neoplasm.

CCL21 Facilitates Chemoresistance and Cancer Stem Cell-Like Properties of Colorectal Cancer Cells through AKT/GSK-3β/Snail Signals

Some evidence indicated that chemoresistance associates with the acquisition of cancer stem-like properties. Recent studies suggested that chemokines can promote the chemoresistance and stem cell properties in various cancer cells, while the underling mechanism is still not completely illustrated. In our study, we found that CCL21 can upregulate the expression of P-glycoprotein (P-gp) and stem cell property markers such as Bmi-1, Nanog, and OCT-4 in colorectal cancer (CRC) HCT116 cells and then improve the cell survival rate and mammosphere formation. Our results suggested that Snail was crucial for CCL21-mediated chemoresistance and cancer stem cell property in CRC cells. Further, we observed that CCL21 treatment increased the protein but not mRNA levels of Snail, which suggested that CCL21 upregulates Snail via posttranscriptional ways. The downstream signals AKT/GSK-3β mediated CCL21 induced the upregulation of Snail due to the fact that CCL21 treatment can obviously phosphorylate both AKT and GSK-3β. The inhibitor of PI3K/Akt, LY294002 significantly abolished CCL21 induced chemoresistance and mammosphere formation of HCT116 cells. Collectively, our results in the present study revealed that CCL21 can facilitate chemoresistance and stem cell property of CRC cells via the upregulation of P-gp, Bmi-1, Nanog, and OCT-4 through AKT/GSK-3β/Snail signals, which suggested a potential therapeutic approach to CRC patients.

Significant biomarkers for the management of hepatocellular carcinoma

Surveillance of hepatocellular carcinoma (HCC) is important for early detection. Imaging tests including computed tomography, magnetic resonance imaging and ultrasonography with or without various kinds of contrast medium are important options for detecting HCC. In addition to the imaging tests, various kinds of biomarkers including alpha-fetoprotein (AFP), lectin-bound AFP (AFP-L3) and protein induced by vitamin K absence or antagonist II (PIVKA-II) have been widely used to detect HCC and analyze treatment response. Recently, various kinds of novel biomarkers (proteins and miRNA) have been found to predict the malignancy potential of HCC and treatment response to specific therapies. Moreover, various combinations of well-established biomarkers and novel biomarkers have been tested to improve sensitivity and specificity. In practical terms, biomarkers that can be analyzed using peripheral blood samples might be more useful than immunohistochemical techniques. It has been reported that quantification of cytokines in peripheral blood and the analysis of peripheral immune subsets could be good biomarkers for managing HCC. Here, we describe the usefulness of and update well-established and novel biomarkers for the management of HCC.

Differentially expressed gene profiles of intrahepatic cholangiocarcinoma, hepatocellular carcinoma, and combined hepatocellular-cholangiocarcinoma by integrated microarray analysis

Intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC) are common primary liver cancers worldwide. However, the survival and prognosis of ICC are much poorer than those of HCC, indicating the different molecular characteristics and mechanisms between ICC and HCC. To identify differentially expressed (DE) genes between ICC and HCC or combined hepatocellular-cholangiocarcinoma (CHC), we performed integrated analysis of publicly available microarray Gene Expression Omnibus (GEO) datasets by MetaOmics. Three GEO datasets comprising 32 ICC biochips, 77 HCC biochips, and 34 CHC biochips were available for the data integration. We identified 7313 DE genes between ICC and HCC, including 3650 upregulated genes and 3663 downregulated genes. The S100 family members on chromosome 1q21 were extensively upregulated in ICC, and S100A11 had the greatest degree of upregulation in ICC. Based on the DE genes, combined gene ontology and Kyoto Encyclopedia of Genes and Genomes analysis showed the enhanced pathways of local adhesion, ECM-receptor interaction, and regulation of action cytoskeleton, suggesting the enhanced communication between ICC and the microenvironment. Additionally, development-related genes and development-related pathways, including the Notch, Wnt, and TGF-β signaling pathways, were shown to be active prominently in ICC. Taken together, we identified the characteristically upregulated or downregulated DE genes and pathways in ICC compared with HCC or CHC. These DE genes and pathways supply new transcriptomics evidence for ICC and could help identify new therapeutic targets.

Mesenchymal stem cell-induced doxorubicin resistance in triple negative breast cancer

Triple negative breast cancer (TNBC) is an aggressive histological subtype with limited treatment options and a worse clinical outcome compared with other breast cancer subtypes. Doxorubicin is considered to be one of the most effective agents in the treatment of TNBC. Unfortunately, resistance to this agent is common. In some drug-resistant cells, drug efflux is mediated by adenosine triphosphate-dependent membrane transporter termed adenosine triphosphate-binding cassette (ABC) transporter, which can drive the substrates across membranes against concentration gradient. In the tumor microenvironment, upon interaction with mesenchymal stem cells (MSCs), tumor cells exhibit altered biological functions of certain gene clusters, hence increasing stemness of tumor cells, migration ability, angiogenesis, and drug resistance. In our present study, we investigated the mechanism of TNBC drug resistance induced by adipose-derived MSCs. Upon exposure of TNBC to MSC-secreted conditioned medium (CM), noticeable drug resistance against doxorubicin with markedly increased BCRP protein expression was observed. Intracellular doxorubicin accumulation of TNBC was also decreased by MSC-secreted CM. Furthermore, we found that doxorubicin resistance of TNBC was mediated by IL-8 presented in the MSC-secreted CM. These findings may enrich the list of potential targets for overcoming drug resistance induced by MSCs in TNBC patients.