Antitumor efficacy of viable tumor vaccine modified by heterogenetic ESAT-6 antigen and cytokine IL-21 in melanomatous mouse

Hacking the Immune Response to Solid Tumors: Harnessing the Anti-Cancer Capacities of Oncolytic Bacteria

Oncolytic bacteria are a classification of bacteria with a natural ability to specifically target solid tumors and, in the process, stimulate a potent immune response. Currently, these include species of Klebsiella, Listeria, Mycobacteria, Streptococcus/Serratia (Coley's Toxin), Proteus, Salmonella, and Clostridium. Advancements in techniques and methodology, including genetic engineering, create opportunities to "hijack" typical host-pathogen interactions and subsequently harness oncolytic capacities. Engineering, sometimes termed "domestication", of oncolytic bacterial species is especially beneficial when solid tumors are inaccessible or metastasize early in development. This review examines reported oncolytic bacteria-host immune interactions and details the known mechanisms of these interactions to the protein level. A synopsis of the presented membrane surface molecules that elicit particularly promising oncolytic capacities is paired with the stimulated localized and systemic immunogenic effects. In addition, oncolytic bacterial progression toward clinical translation through engineering efforts are discussed, with thorough attention given to strains that have accomplished Phase III clinical trial initiation. In addition to therapeutic mitigation after the tumor has formed, some bacterial species, referred to as "prophylactic", may even be able to prevent or "derail" tumor formation through anti-inflammatory capabilities. These promising species and their particularly favorable characteristics are summarized as well. A complete understanding of the bacteria-host interaction will likely be necessary to assess anti-cancer capacities and unlock the full cancer therapeutic potential of oncolytic bacteria.

Elevated IL-35 level and iTr35 subset increase the bacterial burden and lung lesions in Mycobacterium tuberculosis-infected mice

This study aimed to investigate the relationship between interleukin (IL)-35 level and IL-35-producing regulatory T cells (iTr35 subset) in Mycobacterium tuberculosis (Mtb)-infected mice. After the mice were injected with Mtb strain H37R via tail vein, the bacterial burden, lung lesions, and the impact of immune suppression on the infected mice were respectively assessed. The results, when compared with the control mice, showed that the mRNA expression levels of the p35 and Epstein-Barr virus-induced gene 3 of IL-35 were significantly increased in the Mtb-infected mouse spleen at 4 or 8 weeks post-infection and their protein expression levels were concurrently increased in the lungs of the mice, especially in 8 week infected mice. In addition, the levels of serum IL-35 and the iTr35 subset in the spleen of mice were also increased in 4 or 8 weeks post-infection compared with the control mice. Importantly, the high bacterial burden and lung lesions and the low mouse weight were found at 8 week post-infection. Therefore, the mice infected with Mtb resulted in elevating IL-35 level and iTr35 subset and increasing bacterial burden and lung lesions. The findings from the study suggest IL-35 and iTr35 cells may exert an immune suppression role in chronic Mtb-infected mice.

Effects of Mycobacterium bovis Calmette et Guérin (BCG) in oncotherapy: Bladder cancer and beyond

The Mycobacterium bovis Bacillus Calmette et Guérin (BCG) vaccine was generated in 1921 with the efforts of a team of investigators, Albert Calmette and Camille Guérin, dedicated to the determination to develop a vaccine against active tuberculosis (TB) disease. Since then, BCG vaccination is used globally for protection against childhood and disseminated TB; however, its efficacy at protecting against pulmonary TB in adult and aging populations is highly variable. Due to the BCG generated immunity, this vaccine later proved to have an antitumor activity; though the standing mechanisms behind are still unclear. Recent studies indicate that both innate and adaptive cell responses may play an important role in BCG eradication and prevention of bladder cancer. Thus, cells such as natural killer (NK) cells, macrophages, dendritic cells, neutrophils but also MHC-restricted CD4 and CD8 T cells and γδ T cells may play an important role and can be one the main effectors in BCG therapy. Here, we discuss the role of BCG therapy in bladder cancer and other cancers, including current strategies and their impact on the generation and sustainability of protective antitumor immunity against bladder cancer.

Liposomal paclitaxel induces apoptosis, cell death, inhibition of migration capacity and antitumoral activity in ovarian cancer

The main goal of this study is to evaluate the efficacy of the paclitaxel (PTX) drug formulated with a liposomal nanosystem (L-PTX) in a peritoneal carcinomatosis derived from ovarian cancer. In vitro cell viability studies with the human ovarian cancer line A2780 showed a 50% decrease in the inhibitory concentration for L-PTX compared to free PTX. A2780 cells treated with the L-PTX formulation demonstrated a reduced capacity to form colonies in comparison to those treated with PTX. Cell death following L-PTX administration hinted at apoptosis, with most cells undergoing initial apoptosis. A2780 cells exhibited an inhibitory migration profile when analyzed by Wound Healing and real-time cell analysis (xCELLigence) methods after L-PTX administration. This inhibition was related to decreased expression of the zinc finger E-box-binding homeobox 1 (ZEB1) and transforming growth factor 2 (TGF-β2) genes. In vivoL-PTX administration strongly inhibited tumor cell proliferation in ovarian peritoneal carcinomatosis derived from ovarian cancer, indicating higher antitumor activity than PTX. L-PTX formulation did not show toxicity in the mice model. This study demonstrated that liposomal paclitaxel formulations are less toxic to normal tissues than free paclitaxel and are more effective in inhibiting tumor cell proliferation/migration and inducing ZEB1/TGF-β2 gene expression.

Mycobacteria-Based Vaccines as Immunotherapy for Non-urological Cancers

The arsenal against different types of cancers has increased impressively in the last decade. The detailed knowledge of the tumor microenvironment enables it to be manipulated in order to help the immune system fight against tumor cells by using specific checkpoint inhibitors, cell-based treatments, targeted antibodies, and immune stimulants. In fact, it is widely known that the first immunotherapeutic tools as immune stimulants for cancer treatment were bacteria and still are; specifically, the use of Mycobacterium bovis bacillus Calmette-Guérin (BCG) continues to be the treatment of choice for preventing cancer recurrence and progression in non-invasive bladder cancer. BCG and also other mycobacteria or their components are currently under study for the immunotherapeutic treatment of different malignancies. This review focuses on the preclinical and clinical assays using mycobacteria to treat non-urological cancers, providing a wide knowledge of the beneficial applications of these microorganisms to manipulate the tumor microenvironment aiming at tumor clearance.

Decreasing Microtubule Actin Cross-Linking Factor 1 Inhibits Melanoma Metastasis by Decreasing Epithelial to Mesenchymal Transition

Background

The microtubule actin cross-linking factor 1 (MACF1) is involved in cellular migration, adhesion, and invasion processes. Its abnormal expression initiates tumor cell proliferation and metastasis in numerous cancer types.

Methods

In this study, we utilized short hair-pin RNA interference of MACF1 to assess the inhibitory effects on the metastatic potential of B16F10 melanoma cells both in vitro and in vivo a mouse model.

Results

The MACF1 expression was increased in B16F10 cells-induced tumor tissues; while the down-regulation of MACF1 impacted the B16F10 melanoma cell metastatic behavior by decreasing the ability of colony formation and invasion in vitro as well as inhibiting B16F10 cells-induced tumor growth and lung metastasis in vivo. The results of Western blot and immunohistochemistry indicated that the expression of E-cadherin and Smad-7 was significantly increased whereas the expression of N-cadherin and TGF-β1 was significantly decreased in tumor tissue of mice challenged with the B16F10/MACF1-RNAi cells when compared with the B16F10 cells challenged mice.

Conclusion

The data presented in this study demonstrated that down-regulated MACF1 expression decreased B16F10 melanoma metastasis in mice by inhibiting the epithelial to mesenchymal transition program. Thus, MACF1 may be a novel target for melanoma therapy.

Diagnostic and therapeutic applications of miRNA-based strategies to cancer immunotherapy

Cancer immunotherapy has shown impressive clinical results in the last decade, improving both solid and hematologic cancer patients' overall survival. Nevertheless, most of the molecular aspects underlying the response to this approach are still under investigation. miRNAs in particular have been described as regulators of a plethora of different immunologic processes and thus have the potential to be key in the future developments of immunotherapy. In this review, we summarize and discuss the emerging role of miRNAs in the diagnosis and therapeutics of the four principal cancer immunotherapy approaches: immune checkpoint blockade, adoptive cell therapy, cancer vaccines, and cytokine therapy. In particular, this review is focused on potential roles for miRNAs to be adjuvants in soluble factor- and cell-based therapies, with the aim of helping to increase specificity and decrease toxicity, and on the potential for rationally identified miRNA-based diagnostic approaches to aid in precision clinical immunooncology.

Effective tumor immunity to melanoma mediated by B16F10 cancer stem cell vaccine

Although tumor vaccines have been considered a promising immunotherapy approach, therapeutic tumor vaccines are mostly disappointing in the clinic due to vaccine weak immunogenicity. Cancer stem cells (CSCs) may broaden the antigenic breadth and effectively induce the immune responses against autologous cancer cells. Here we report on the development of the B16F10 CD133⁺CD44⁺CSCs (B16F10 CSCs) vaccine to induce tumor immunity to melanoma in mice. Efficacy of against melanoma was evaluated by analysis of tumor growth and mouse survival. Immunogenicity was assessed by ELISA and flow cytometric assays, including serum cytokines, cytotoxic activity of NK cells and splenocytes in the immunized mice. The results showed that the B16F10 CSC vaccine resulted in tumor shrinkage and mouse lifespan extension. The cytotoxic activity and IFN-γ level were significantly increased in mice immunized with B16F10 CSC vaccine compared with the mice immunized with control vaccines. Additionally, New York esophageal squamous cell carcinoma-1, an efficient tumor associated antigen over-expressed by B16F10 CSCs, was markedly reduced in expression in melanoma tissue, suggesting decrease of CSC subpopulation due to B16F10 CSC vaccination. Collectively, the findings may represent a new powerful approach for treatment of melanoma by B16F10 CSC vaccination.

Combining TGF-β1 knockdown and miR200c administration to optimize antitumor efficacy of B16F10/GPI-IL-21 vaccine

TGF-β1 secreted abundantly by tumors cells as well as present in the local microenvironment promotes neoplasm invasion and metastasis by triggering the epithelial to mesenchymal transition (EMT). MiR200c has been shown to suppress EMT and to regulate the cellular epithelial and interstitial state conversion, whereas the tumor vaccines are intended to specifically initiate or amplify a host response against evolving tumor cells. Our study aimed at optimizing the antitumor effects of the B16F10/glycosylphosphatidylinositol-interleukin 21 (B16F10/GPI-IL-21) tumor vaccine on melanoma bearing mice by combining the TGF-β1 knockdown and the administration of miR200c agomir. The mice were subcutaneously vaccinated with inactivated B16F10/GPI-IL-21 vaccine and challenged by B16F10 cells transfected with shTGF-β1 (B16F10/shTGF-β1 cells) or B16F10/shTGF-β1 cells with the administration of miR200c agomir. The later combination showed that, when compared with the mice in the control group that received no vaccination, vaccinated mice significantly increased NK and CTL activities, enhanced levels of IFN-γ, and reduced expression of TGF-β1, N-cadherin, Vimentin, Gli1/2, P-Smad2/3 and others involved in promoting expression of EMT-related molecules in tumor areas, and inhibited the melanoma metastasis in lungs and lymph nodes. Altogether, our findings demonstrate that this synergistic anti-cancer regimen effectively induces strong immune response and diminishes the melanoma progression.

Reinforcing B16F10/GPI-IL-21 vaccine efficacy against melanoma by injecting mice with shZEB1 plasmid or miR200c agomir

In this study, we hypothesized that the inhibition of epithelial to mesenchymal transition (EMT) program by knockdown of Zinc-finger E-box binding homeobox 1 (ZEB1) or administration of miR200c agomir would strengthen the B16F10 cells transfected with GPI-anchored IL-21 (B16F10/GPI-IL-21) vaccine efficacy in inhibiting the melanoma metastasis. Our findings from the current study indicated that, when compared with the mice immunized with the B16F10/GPI-IL-21 vaccine alone, the mice immunized with B16F10/GPI-IL-21 vaccine combined with injection of shZEB1 plasmid or miR200c agomir not only meaningfully inhibited EMT of melanoma, reduced the EMT characteristic molecular expression in tumor tissues, but also significantly decreased the Treg cells and TGF-β1, enhanced the cytotoxicities of NK cells and cytotoxic T lymphocytes and the IFN-γ level. Furthermore, the immunotherapeutic combination resulted in inhibiting the melanoma growth and lung metastasis. Our study demonstrated that using the B16F10/GPI-IL-21 vaccine in combination with the down-regulated ZEB1 or miR200c administration effectively elicited anti-tumor immunity and reduced melanoma metastasis by inhibiting the EMT program in the B16F10 melanoma-bearing mice.

Novel Antitumor Strategy Utilizing a Plasmid Expressing a Mycobacterium tuberculosis Antigen as a "Danger Signal" to Block Immune Escape of Tumor Cells

Immune escape of tumor cells is one of the main obstacles hindering the effectiveness of cancer immunotherapy. We developed a novel strategy to block immune escape by transfecting tumor cells in vivo with genes of pathogenic antigens from Mycobacterium tuberculosis (TB). This induces presentation of the TB antigen on tumor cell surfaces, which can be recognized by antigen presenting cells (APCs) as a “danger signal” to stimulate antitumor immune response. This strategy is also expected to amplify the immune response against tumor-associated antigens, and block immune escape of the tumor. DNA/PEI/chondroitin sulfate ternary complex is a highly effective non-viral gene vector system for in vivo transfection. A therapeutic complex was prepared using a plasmid encoding the TB antigen, early secretory antigenic target-6 (ESAT-6). This was injected intratumorally into syngeneic tumor-bearing mice, and induced significant tumor growth suppression comparable to or higher than similar complexes expressing cytokines such as interleukin-2 (IL-2) and interleukin-12 (IL-12). Co-transfection of the cytokine-genes and the ESAT-6-gene enhanced the antitumor efficacy of either treatment alone. In addition, complete tumor regression was achieved with the combination of ESAT-6 and IL-2 genes.

Downregulated lincRNA HOTAIR expression in ovarian cancer stem cells decreases its tumorgeniesis and metastasis by inhibiting epithelial-mesenchymal transition

Background

Emerging evidence indicates that dysregulated long intervening non-coding RNA (lincRNA) HOTAIR correlates highly with tumor invasion and metastasis but a link between the high expression of HOTAIR and the metastatic cascade of cancer stem cells (CSCs) needs to be further studied. The purpose of this study was to investigate the effect of down-regulated HOTAIR expression on tumorgeniesis and metastasis of epithelial ovarian cancer (EOC) CSCs. CD117⁺CD44⁺CSCs were isolated from human EOC SKOV3 cell line by using a magnetic-activated cell sorting system, and were then transfected with the expression vector-based small hairpin RNA targeting HOTAIR; the stably transfected cells were selected for the study. Colony-forming, wound-healing, cellular metastasis and tumorigenicity assays were performed.

Results

The results demonstrated that the HOTAIR expression in clinical EOC tissues and SKOV3 CD117⁺CD44⁺CSCs was higher than in SKOV3 tumor tissues and non-CD117⁺CD44⁺CSCs. The CD117⁺CD44⁺-shHOTAIR showed an inhibited HOTAIR expression, reduced cell migration and invasion than CD117⁺CD44⁺- scramble, suggesting the inhibition of an epithelial-mesenchymal transition. Moreover, the downregulated HOTAIR expression in CD117⁺CD44⁺ CSCs significantly decreased the tumor growth and lung metastasis in xenograft mice.

Conclusion

Our findings demonstrated the shHOTAIR-mediated down-regulation of the HOTAIR expression in CD117⁺CD44⁺ CSCs can be a promising new opportunity for future clinical trials.

Observation of ovarian cancer stem cell behavior and investigation of potential mechanisms of drug resistance in three-dimensional cell culture

Cancer cells behave differently in a three-dimensional (3D) cell culture compared with in the conventional two-dimensional (2D) one. Accumulated evidences indicate that the characteristics of cancer stem cells (CSCs) are different from common cancer cells due to their ability to produce tumors and resist chemoradiation. The objective of this work was to observe CSC behavior and investigate the potential mechanisms of CSC drug resistance in 3D versus 2D in vitro environment. We first demonstrated that the CD44(+)CD117(+)cells isolated from the human epithelial ovarian cancer HO8910 cell line have the properties of CSCs that revealed faster growth, larger tumorsphere and stronger survival potential in the hypoxic environment in 3D cell culture as well as more powerful tumorigenicity in a xenograft mice than the HO8910 cells. The CD44(+)CD117(+)CSCs also exhibited high chemoresistance to anticancer drugs when the cells were incubated with 5-fluorouracil, cisplatin and carboplatin, respectively in 3D versus 2D environment. This might be associated with the high expression of ABCG2, ABCB1 and the high expression of MMP-2 and MMP-9 in CD44(+)CD117(+)CSCs. Overall, these results suggest the advantages of using 3D culture model to accurately display CSC behavior in vitro. 3D model may improve the efficacy of screening anticancer drugs for treatment of ovarian CSCs.

Regulation gene expression of miR200c and ZEB1 positively enhances effect of tumor vaccine B16F10/GPI-IL-21 on inhibition of melanoma growth and metastasis

Background

Genetically modified cells have been shown to be one of the most effective tumor vaccine strategies. However, in many cases, such as in melanoma, induction of a potent immune responses against the disease still remains a major challenge. Thus, novel strategies to reinforce tumor vaccine efficacy are needed. Using microRNA (miR) and Zinc-finger E-box binding homeobox (ZEB) have received much attention for potentially regulating tumor progression. To elicit a potent antitumor efficacy against melanoma, we used tumor vaccine in combination with miR200c overexpression or ZEB1 knockdown to assess the efficacy of treatment of murine melanoma.

Methods

B16F10 cell vaccine expressing interleukin 21 (IL-21) in the glycosylpho- sphatidylinositol (GPI)-anchored form (B16F10/GPI-IL-21) were developed. The vaccine was immunized into mice challenged by B16F10 cells or B16F10 cells stably transduced with lentiviral-miR200c (B16F10/miR200c) or transfected with the ZEB1-shRNA recombinant (B16F10/shZEB1) or the B16F10/GPI-IL-21 vaccine. The immune responses, tumorigenicity and lung metastasis in mice were evaluated, respectively.

Results

The vaccination with B16F10/GPI-IL-21 markedly increased the serum cytokine levels of IFN-γ, TNF-α, IL-4 and decreased TGF-β level as well as augmented the cytotoxicity of splenocytes in immunized mice compared with control mice. In addition, the tumor vaccine B16F10/GPI-IL-21 significantly inhibited the tumor growth and reduced counts of lung metastases in mice challenged by B16F10/GPI-IL-21, B16F10/shZEB1 and B16F10/miR200c respectively compared with the control mice challenged by B16F10 cells. The efficacy mechanisms may involve in reinforcing immune responses, increasing expression of miR200c, E-cadherin and SMAD-7 and decreasing expression of TGF-β, ZEB1, Vimentin and N-cadherin in tumor tissues from the immunized mice.

Conclusions

These results indicate that the tumor vaccine B16F10/GPI-IL-21 in combination with miR200c overexpression or ZEB1 knockdown effectively inhibited melanoma growth and metastasis a murine model. Such a strategy may, therefore, be used for the clinical trials.

ESAT-6-gpi DNA vaccine augmented the specific antitumour efficacy induced by the tumour vaccine B16F10-ESAT-6-gpi/IL-21 in a mouse model

In this study, we hypothesized that the mice immunized with the glycosylphosphatidylinositol (GPI) anchored 6-kDa early-secreted antigenic target (ESAT-6) DNA vaccine (ESAT-6-gpi) and the tumour vaccine B16F10-ESAT-6-gpi/IL-21 might significantly enhance immune responses and antimelanoma efficacy. Our experimental results indicated that the anti-ESAT-6 antibody induced by the DNA vaccine ESAT-6-gpi bound ESAT-6 to the surface of tumour vaccine to activate a complement classical pathway and resulted in the B16F10 tumour cell lysis and apoptosis, which served as a potential trigger for breaking melanomatous immune tolerance to elicit an initiation of natural antimelanoma immunity. Our innovative approach of using the DNA vaccine ESAT-6-gpi priming and the tumour vaccine B16F10-ESAT-6-gpi/IL-21 boosting induced strong antimelanoma immunity that inhibited melanomatous growth. These findings highlighted the DNA vaccine ESAT-6-gpi as an immune enhancer to augment the immune efficacy of the tumour vaccine B16F10-ESAT -6-gpi/IL-21 against melanoma in a mouse model.

MicroRNA-200c overexpression inhibits tumorigenicity and metastasis of CD117+CD44+ ovarian cancer stem cells by regulating epithelial-mesenchymal transition

Background

Cancer stem cells (CSCs) are believed to be ‘seed cell’ in cancer recurrence and metastasis. MicroRNAs (miRNAs) can play an important role in the progression of primary tumor towards metastasis by regulating the epithelial-mesenchymal transition (EMT). The goal of this study was to investigate the effect of miRNA-200c overexpression on the EMT, tumorigenicity and metastasis of epithelial ovarian cancer (EOC) CSCs.

Methods

The EOC CD117⁺CD44⁺CSCs were isolated from the human ovarian cancer cell line SKOV3 by using a magnetic-activated cell sorting system, and the lentivirus miR-200c transduced CSCs were then selected for the study. The assays of colony forming, wound healing, cellular migration in vitro and tumor progression in vivo were performed.

Results

The miR-200c expression was reduced in the CD117⁺CD44⁺CSCs compared with the non-CD117⁺CD44⁺CSCs. However, the stable overexpression of the miR-200c in the CD117⁺CD44⁺CSCs resulted in a significant down-regulation of ZEB-1 and the Vimentin expression, an upregulation of the E-cadherin expression as well as a decrease of colony forming, migratory and invasion in vitro. Importantly, the miR-200c overexpression significantly inhibited the CD117⁺CD44⁺CSCs xenograft growth and lung metastasis in vivo in nude mice by inhibition of the EMT. In addition, the down-regulation of ZEB-1 showed the same efficacy as the miR-200c overexpression in the CD117⁺CD44⁺CSCs.

Conclusion

These findings from this study suggest that the miR-200c overexpression may be considered a critical approach for the EOC CD117⁺CD44⁺CSCs in clinical trials.

Paclitaxel-Fe3O4 nanoparticles inhibit growth of CD138(-) CD34(-) tumor stem-like cells in multiple myeloma-bearing mice

BACKGROUND

There is growing evidence that CD138(-) CD34(-) cells may actually be tumor stem cells responsible for initiation and relapse of multiple myeloma. However, effective drugs targeted at CD138(-) CD34(-) tumor stem cells are yet to be developed. The purpose of this study was to investigate the inhibitory effect of paclitaxel-loaded Fe3O4 nanoparticles (PTX-NPs) on CD138(-) CD34(-) tumor stem cells in multiple myeloma-bearing mice.

METHODS

CD138(-) CD34(-) cells were isolated from a human U266 multiple myeloma cell line using an immune magnetic bead sorting method and then subcutaneously injected into mice with nonobese diabetic/severe combined immunodeficiency to develop a multiple myeloma-bearing mouse model. The mice were treated with Fe3O4 nanoparticles 2 mg/kg, paclitaxel 4.8 mg/kg, and PTX-NPs 0.64 mg/kg for 2 weeks. Tumor growth, pathological changes, serum and urinary interleukin-6 levels, and molecular expression of caspase-3, caspase-8, and caspase-9 were evaluated.

RESULTS

CD138(-) CD34(-) cells were found to have tumor stem cell characteristics. All the mice developed tumors in 40 days after injection of 1 × 10(6) CD138(-) CD34(-) tumor stem cells. Tumor growth in mice treated with PTX-NPs was significantly inhibited compared with the controls (P < 0.005), and the groups that received nanoparticles alone (P < 0.005) or paclitaxel alone (P < 0.05). In addition, the PTX-NPs markedly inhibited interleukin-6 secretion, increased caspase-8, caspase-9, and caspase-3 expression, and induced apoptosis of tumor cells in the treated mice.

CONCLUSION

PTX-NPs proved to be a potent anticancer treatment strategy that may contribute to targeted therapy for multiple myeloma tumor stem cells in future clinical trials.

Anti-cancer versus cancer-promoting effects of the interleukin-17-producing T helper cells

Research on T helper 17 (Th17) cells with regard to immunoediting has revealed elusive results. Whereas enhanced Th17 response and related molecules such as interleukin (IL)-17, IL-21, IL-22, IL-23 and STAT3 accompanied tumor induction and progression, finding that tumor growth/stage was negatively correlated with increased infiltration of Th17 cells in the tumor mass has prompted elucidation of various antitumor mechanisms elicited by Th17 and their related molecules. The pro-tumor efficacy of Th17 response included promotion of neutrophilia and induction of angiogenic (e.g. VEGF, MMP2 and MMP9) and anti-apoptotic factors (e.g. Bcl-XL), as well as expansion and activation of myeloid-derived suppressor cells, which facilitate generation of tumor-specific regulatory T cells. Other tumor immunogenic settings revealed anti-tumor pathways including induction of cytotoxic activity, expression of MHC antigens, the ability Th17 cells to reside within the tumor, and to convert into IFN-γ producers. Notably, Th17 cell related molecules exert indirect pro- or anti-tumor effects via inducing viral persistence or mediating protective mechanisms against bacterial and viral infection. Herein, the recent literature revealing such immunoediting events mediated by Th17 cells and their associated molecules as delivered by various experimental regimens and observed in cancer patient are revised, with a focus on some proposed anti-cancer therapies.