Tumor Eradication by Cisplatin Is Sustained by CD80/86-Mediated Costimulation of CD8+ T Cells

The role of cisplatin in modulating the tumor immune microenvironment and its combination therapy strategies: a new approach to enhance anti-tumor efficacy

Cisplatin is a platinum-based drug that is frequently used to treat multiple tumors. The anti-tumor effect of cisplatin is closely related to the tumor immune microenvironment (TIME), which includes several immune cell types, such as the tumor-associated macrophages (TAMs), cytotoxic T-lymphocytes (CTLs), dendritic cells (DCs), myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs), and natural killer (NK) cells. The interaction between these immune cells can promote tumor survival and chemoresistance, and decrease the efficacy of cisplatin monotherapy. Therefore, various combination treatment strategies have been devised to enhance patient responsiveness to cisplatin therapy. Cisplatin can augment anti-tumor immune responses in combination with immune checkpoint blockers (such as PD-1/PD-L1 or CTLA4 inhibitors), lipid metabolism disruptors (like FASN inhibitors and SCD inhibitors) and nanoparticles (NPs), resulting in better outcomes. Exploring the interaction between cisplatin and the TIME will help identify potential therapeutic targets for improving the treatment outcomes in cancer patients.

Tumor-derived extracellular vesicles: Hijacking T cell function through exhaustion

Extracellular vesicles (EVs) play a vital role in intercellular communication within the tumor microenvironment (TME). These vesicles, secreted by tumor cells, contain proteins, lipids, and nucleic acids that significantly influence immune responses, particularly impacting T-cell function. In cancer, T cell dysfunction and exhaustion-marked by reduced proliferation, diminished cytokine production, and impaired cytotoxic activity-are key barriers to effective immune responses. Tumor-derived extracellular vesicles (TEVs) contribute to this dysfunction by carrying immunosuppressive molecules, such as transforming growth factor-beta (TGF-β) and various microRNAs (miRNAs). These TEV-mediated mechanisms promote T cell exhaustion and foster a broader immunosuppressive environment, enabling tumor progression and immune evasion. Furthermore, TEVs have been implicated in resistance to cancer immunotherapies, including immune checkpoint inhibitors and T cell therapies. Understanding the molecular pathways and cargoes within TEVs that drive T cell dysfunction is crucial for developing novel therapeutic strategies aimed at reinvigorating exhausted T cells, enhancing anti-tumor immunity, and improving cancer treatment outcomes.

Efficacy of PD-1 blockade plus chemotherapy in patients with oncogenic-driven non-small-cell lung cancer

BACKGROUND

PD-1 blockade plus chemotherapy has become the first-line standard of care for patients with advanced non-small-cell lung cancer (NSCLC) without oncogenic drivers. Oncogenic-driven advanced NSCLC showed limited response to PD-1 blockade monotherapy or chemotherapy alone. Whether NSCLC patients with oncogenic drivers could benefit from PD-1 blockade plus chemotherapy remains undetermined.

METHODS

Three hundred twelve NSCLC patients with at least one oncogenic driver alteration received PD-1 plus chemotherapy or each monotherapy were retrospectively identified. Objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) were compared to evaluate the therapeutic outcomes differences among patients with different oncogenic drivers.

RESULTS

One hundred sixty-two patients received PD-1 blockade plus chemotherapy, 57 received PD-1 blockade monotherapy and 93 received chemotherapy alone were included. Oncogenic driver mutations including KRAS (31.4%), EGFR (28.8%), HER2 (14.7%), BRAF (10.6%), RET (7.4%), and other mutations (7.1%) were identified. Patients with oncogenic drivers who received PD-1 blockade plus chemotherapy had significantly better outcomes compared to those received PD-1 blockade or chemotherapy alone (ORR: 51% vs. 18% vs. 25%, P < 0.001; median PFS: 10.0 [95% CI: 8.9-12.6] vs. 3.7 [95% CI: 2.9-5.1] vs. 5.3 [95% CI: 4.5-6.2] months, P < 0.001; median OS: 26.0 [95% CI: 23.0-30.0] vs. 14.3 [95% CI: 9.6-19.8] vs. 16.1 [95% CI: 11.6-21.9] months, P < 0.001). The superior efficacy was consistently found in separate analyses for patients received first-line and second/third line treatments. Among individual gene alterations, patients with KRAS, EGFR, or BRAF mutations treated with PD-1 blockade plus chemotherapy achieved markedly improved PFS and OS than those received PD-1 blockade or chemotherapy alone. Multivariate Cox regression analysis revealed that PD-1 blockade plus chemotherapy was independently associated with better PFS and OS.

CONCLUSION

PD-1 blockade plus chemotherapy demonstrated superior efficacy than PD-1 blockade monotherapy or chemotherapy alone in patients with oncogenic-driven advanced NSCLC, particularly in KRAS, EGFR and BRAF subgroups. These findings suggest that PD-1 blockade plus chemotherapy may be considered as an optional treatment option for patients without available targeted therapies.

Optimal timing of anti-PD-1 antibody combined with chemotherapy administration in patients with NSCLC

BACKGROUND

Anti-programmed cell death 1 (PD-1) antibody combined with chemotherapy simultaneously is regarded as the standard treatment for patients with advanced non-small cell lung cancer (NSCLC) by current clinical guidelines. Different immune statuses induced by chemotherapy considerably affect the synergistic effects of the chemo-anti-PD-1 combination. Therefore, it is necessary to determine the optimal timing of combination treatment administration.

METHODS

The dynamic immune status induced by chemotherapy was observed in paired peripheral blood samples of patients with NSCLC using flow cytometry and RNA sequencing. Ex vivo studies and metastatic lung carcinoma mouse models were used to evaluate immune activity and explore the optimal combination timing. A multicenter prospective clinical study of 170 patients with advanced NSCLC was performed to assess clinical responses, and systemic immunity was assessed using omics approaches.

RESULTS

PD-1 expression on CD8+ T cells was downregulated on day 1 (D1) and D2, but recovered on D3 after chemotherapy administration, which is regulated by the calcium influx-P65 signaling pathway. Programmed cell death 1 ligand 1 expression in myeloid-derived suppressor cells was markedly reduced on D3. RNA sequencing analysis showed that T-cell function began to gradually recover on D3 rather than on D1. In addition, ex vivo and in vivo studies have shown that anti-PD-1 treatment on D3 after chemotherapy may enhance the antitumor response and considerably inhibit tumor growth. Finally, in clinical practice, a 3-day-delay sequential combination enhanced the objective response rate (ORR, 68%) and disease control rate (DCR, 98%) compared with the simultaneous combination (ORR=37%; DCR=81%), and prolonged progression-free survival to a greater extent than the simultaneous combination. The new T-cell receptor clones were effectively expanded, and CD8+ T-cell activity was similarly recovered.

CONCLUSIONS

A 3-day-delay sequential combination might increase antitumor responses and clinical benefits compared with the simultaneous combination.

Meta-analysis of platinum chemotherapy combinations with immunotherapy in metastatic urothelial carcinoma

The therapeutic landscape for metastatic urothelial carcinoma (mUC) has evolved significantly due to the development of innovative combination treatments, including enfortumab vedotin-pembrolizumab (EVP). Despite these advancements, the limited availability of EVP means that platinum-based chemotherapy regimens continue to serve as the primary treatment modality for many patients with mUC. We evaluated the effect of the type of platinum chemotherapy used in combination with immunotherapy (IO) on treatment outcomes in mUC. The meta-analysis showed that cisplatin-gemcitabine plus IO combination and carboplatin-gemcitabine plus IO combination improve progression-free survival compared to platinum-gemcitabine therapy (hazard ratio [HR] = 0.71, 95% CI: 0.62-0.82; P < .0001 and HR = 0.85, 95% CI: 0.73-0.98; P < .03, respectively). However, only the cisplatin-gemcitabine plus IO combination showed overall survival (OS) benefit (HR = 0.80, 95% CI: 0.69-0.93; P < .003). In comparison to the platinum-gemcitabine combination, neither the cisplatin-gemcitabine plus IO nor the carboplatin-gemcitabine plus IO combinations demonstrated an objective response rate (ORR) benefit. In summary, combining cisplatin-gemcitabine with immunotherapy offers significant overall survival benefits in mUC. The exact mechanisms-whether cisplatin's immunomodulatory effects or patient demographic differences-are yet to be determined, necessitating further research to understand these outcomes better.

Targeting Dectin-1 and or VISTA enhances anti-tumor immunity in melanoma but not colorectal cancer model

PURPOSE

Acquired resistance to immune checkpoint blockers (ICBs) is a major barrier in cancer treatment, emphasizing the need for innovative strategies. Dectin-1 (gene Clec7a) is a C-type lectin receptor best known for its ability to recognize β-glucan-rich structures in fungal cell walls. While Dectin-1 is expressed in myeloid cells and tumor cells, its significance in cancer remains the subject of controversy.

METHODS

Using Celc7a-/- mice and curdlan administration to stimulate Dectin-1 signaling, we explored its impact. VISTA KO mice were employed to assess VISTA's role, and bulk RNAseq analyzed curdlan effects on neutrophils.

RESULTS

Our findings reveal myeloid cells as primary Dectin-1 expressing cells in the tumor microenvironment (TME), displaying an activated phenotype. Strong Dectin-1 co-expression/co-localization with VISTA and PD-L1 in TME myeloid cells was observed. While Dectin-1 deletion lacked protective effects, curdlan stimulation significantly curtailed B16-F10 tumor progression. RNAseq and pathway analyses supported curdlan's role in triggering a cascade of events leading to increased production of pro-inflammatory mediators, potentially resulting in the recruitment and activation of immune cells. Moreover, we identified a heterogeneous subset of Dectin-1+ effector T cells in the TME. Similar to mice, human myeloid cells are the prominent cells expressing Dectin-1 in cancer patients.

CONCLUSION

Our study proposes Dectin-1 as a potential adjunctive target with ICBs, orchestrating a comprehensive engagement of innate and adaptive immune responses in melanoma. This innovative approach holds promise for overcoming acquired resistance to ICBs in cancer treatment, offering avenues for further exploration and development.

Platinum-Based Chemotherapy Induces Opposing Effects on Immunotherapy Response-Related Spatial and Stromal Biomarkers in the Bladder Cancer Microenvironment

PURPOSE

Platinum-based chemotherapy and immune checkpoint inhibitors are key components of systemic treatment for muscle-invasive and advanced urothelial cancer. The ideal integration of these two treatment modalities remains unclear as clinical trials have led to inconsistent results. Modulation of the tumor-immune microenvironment by chemotherapy is poorly characterized. We aimed to investigate this modulation, focusing on potential clinical implications for immune checkpoint inhibitor response.

EXPERIMENTAL DESIGN

We assessed immune cell densities, spatial relations, and tumor/stromal components from 116 patients with urothelial bladder cancer (paired data for 95 patients) before and after platinum-based chemotherapy.

RESULTS

Several published biomarkers for immunotherapy response changed upon chemotherapy treatment. The intratumoral CD8+ T-cell percentage increased after treatment and was associated with increased TNFα-via-NF-κB signaling. The percentage of PDL1+ immune cells was higher after chemotherapy. An increase in chemo-induced changes that potentially inhibit an antitumor immune response was also observed, including increased fibroblast-based TGFβ signaling and distances from immune cells to the nearest cancer cell. The latter two parameters correlated significantly in posttreatment samples, suggesting that TGFβ signaling in fibroblasts may play a role in spatially separating immune cells from cancer cells. We examined specific chemotherapy regimens and found that treatment with methotrexate, vinblastine, doxorubicin, and cisplatin was associated with an increase in the macrophage cell percentage. Gemcitabine-containing chemotherapy was associated with upregulation of fibroblast TGFβ signaling.

CONCLUSIONS

The opposing effects of platinum-based chemotherapy on the immune cell composition and stromal context of the tumor-immune microenvironment may explain the inconsistent results of clinical trials investigating chemotherapy and immune checkpoint inhibitor combinations in bladder cancer.

Upgrading Melanoma Treatment: Promising Immunotherapies Combinations in the Preclinical Mouse Model

Background:

Melanoma, known for its high metastatic potential, does not respond well to existing treatments in advanced stages. As a solution, immunotherapy-based treatments, including anti-PD-1/L1 and anti-CTLA-4, have been developed and evaluated in preclinical mouse models to overcome resistance. Although these treatments display the potential to suppress tumor growth, there remains a crucial requirement for a thorough assessment of long-term efficacy in preventing metastasis or recurrence and improving survival rates.

Methods:

From 2016 onwards, a thorough examination of combined immunotherapies for the treatment of cutaneous melanoma in preclinical mouse models was conducted. The search was conducted using MeSH Terms algorithms in PubMed®, resulting in the identification of forty-five studies that met the rigorous inclusion criteria for screening.

Results:

The C57 mouse model bearing B16-melanoma has been widely utilized to assess the efficacy of immunotherapies. The combination of therapies has demonstrated a synergistic impact, leading to potent antitumor activity. One extensively studied method for establishing metastatic models involves the intravenous administration of malignant cells, with several combined therapies under investigation. The primary focus of evaluation has been on combined immunotherapies utilizing PD- 1/L1 and CTLA-4 blockade, although alternative immunotherapies not involving PD-1/L1 and CTLA-4 blockade have also been identified. Additionally, the review provides detailed treatment regimens for each combined approach.

Conclusion:

The identification of techniques for generating simulated models of metastatic melanoma and investigating various therapeutic combinations will greatly aid in evaluating the overall systemic efficacy of immunotherapy. This will be especially valuable for conducting short-term preclinical experiments that have the potential for clinical studies.

Combining cisplatin with Pinellia pedatisecta Schott lipid-soluble extract induces tumor immunogenic cell death in cervical cancer

BACKGROUND

Pinellia pedatisecta Schott extract (PE) is extracted from Pinellia pedatisecta Schott (PPS), a traditional Chinese medicinal plant with the potential for direct anticancer effects or eliciting an anti-tumor response by activating the immune system.

PURPOSE

To explore PE's ability and mechanism to reconstruct cisplatin's immunogenicity.

METHODS

Cervical cancer cells were treated with cisplatin (CDDP) and/or PE. The exposure of calreticulin (CRT) on cell membrane was investigated by flow cytometry. The extracellular of ATP and HMGB1 was investigated by Western blot analysis, immunofluorescence and ELISA assay. Changes in immune profiles were using flow cytometry in vaccination and anti-tumor assays in vivo. Lastly, the mechanism of PE influenced the ROS/ERS pathway was examined by ROS assay kit, flow cytometry and Western blotting.

RESULTS

PE treatment induced translocation of CRT from the endoplasmic reticulum to the cell membrane of tumor cells, concomitantly triggering immunogenic cell death (ICD). In terms of mechanisms, endoplasmic reticulum (ER) stress relievers could impede the ability of PE to induce immunogenicity. This indicates that PE is activated by ER stress, leading to subsequent induction of ICD. Upon analyzing RNA-seq data, it was observed that PE primarily induces programmed cell death in tumors by impeding upstream antioxidant mechanisms. Additionally, it transforms dying tumor cells into vaccines, activating a series of immune responses.

CONCLUSIONS

This study observed for the first time that PE-induced CRT exposure on the membrane of cervical cancer cells compensates for the defect of nonimmunogenic cell death inducer CDDP thereby stimulating potent ICD. This ability restores the immunogenicity of CDDP through ER stress induced by the ROS signal. ROS played a role in PE's ability to induce ICD, leading to increased expression of ER stress-related proteins, including ATF3 and IRE-1α. PE exerted anti-cancer effects by increasing the ROS levels, and ROS/ERS signaling may be a potential avenue for cervical cancer treatment. Hence, the synergistic use of PE and CDDP holds potential for enhancing immunochemotherapy in cancer treatment.

Bioinformatics analysis and validation of genes related to paclitaxel's anti-breast cancer effect through immunogenic cell death

Research indicated that Paclitaxel (PTX) can induce immunogenic cell death (ICD) through immunogenic modulation. However, the combination of PTX and ICD has not been extensively studied in breast cancer (BRCA). The TCGA-BRCA and GSE20685 datasets were enrolled in this study. Samples from the TCGA-BRCA dataset were consistently clustered based on selected immunogenic cell death-related genes (ICD-RGs). Next, candidate genes were obtained by overlapping differentially expressed genes (DEGs) between BRCA and normal groups, intersecting genes common to DEGs between cluster1 and cluster2 and hub module genes, and target genes of PTX from five databases. The univariate Cox algorithm and the least absolute shrinkage and selection operator (LASSO) were performed to obtain biomarkers and build a risk model. Following observing the immune microenvironment in differential risk subgroups, single-gene gene set enrichment analysis (GSEA) was carried out in all biomarkers. Finally, the expression of biomarkers was analyzed. Enrichment analysis showed that 626 intersecting genes were linked with inflammatory response. Further five biomarkers (CHI3L1, IL18, PAPLN, SH2D2A, and UBE2L6) were identified and a risk model was built. The model's performance was validated using GSE20685 dataset. Furthermore, the biomarkers were enriched with adaptive immune response. Lastly, the experimental results indicated that the alterations in IL18, SH2D2A, and CHI3L1 expression after treatment matched those in the public database. In this study, Five PTX-ICD-related biomarkers (CHI3L1, IL18, PAPLN, SH2D2A, and UBE2L6) were identified to aid in predicting BRCA treatment outcomes.

RNA is a pro-apoptotic target of cisplatin in cancer cell lines and C. elegans

Cisplatin not only targets DNA but also RNA. However, it is largely unknown whether platinated RNA (Pt-RNA) causes apoptosis and thus contributes to the cytotoxic effects of cisplatin. Consequently, cellular RNA was isolated from HepG2 and LS180 cells, exposed to cisplatin, and the resulting Pt-RNA (20 ng Pt/µg RNA) was transfected into these cancer cell lines or used to treat an apoptosis reporter Caenorhabditis elegans (C. elegans) strain (MD701, expressing CED-1::GFP). Cellular and molecular effects of Pt-RNA were evaluated by luminogenic caspase 3/7 assays, PCR array analysis, and fluorescence microscopy-based quantification of apoptosis in C. elegans gonads. Assuming RNA cross-linking (pseudo double-stranded RNA), the contribution of the Toll-like receptor 3 (TLR3, a sensor of double-stranded RNA) to apoptosis induction in cancer cell lines was investigated by pharmacological TLR3 inhibition and overexpression. In contrast to controls, Pt-RNA significantly enhanced apoptosis in C. elegans (2-fold) and in the cancer cell lines (2-fold to 4-fold). TLR3 overexpression significantly enhanced the pro-apoptotic effects of Pt-RNA in HepG2 cells. TLR3 inhibition reduced the pro-apoptotic effects of Pt-RNA and cisplatin, but not of paclitaxel (off-target control). Gene expression analysis showed that Pt-RNA (but not RNA) significantly enhanced the mRNA levels of nuclear factor kappa B subunit 2 and interleukin-8 in HepG2 cells, suggesting that Pt-RNA is a damage-associated molecular pattern that additionally causes pro-inflammatory responses. Together, this data suggests that not only DNA but also cellular RNA is a functionally relevant target of cisplatin, leading to pro-apoptotic and immunogenic effects.

Peritumoral administration of immunomodulatory antibodies as a triple combination suppresses skin tumor growth without systemic toxicity

BACKGROUND

Skin cancers, particularly keratinocyte cancers, are the most commonly diagnosed tumors. Although surgery is often effective in early-stage disease, skin tumors are not always easily accessible, can reoccur and have the ability to metastasize. More recently, immunotherapies, including intravenously administered checkpoint inhibitors, have been shown to control some skin cancers, but with off-target toxicities when used in combination. Our study investigated whether peritumoral administration of an antibody combination targeting PD-1, 4-1BB (CD137) and VISTA might control skin tumors and lead to circulating antitumor immunity without off-target toxicity.

METHODS

The efficacy of combination immunotherapy administered peritumorally or intravenously was tested using transplantable tumor models injected into mouse ears (primary tumors) or subcutaneously in flank skin (secondary tumors). Changes to the tumor microenvironment were tracked using flow cytometry while tumor-specific, CD8 T cells were identified through enzyme-linked immunospot (ELISPOT) assays. Off-target toxicity of the combination immunotherapy was assessed via serum alanine aminotransferase ELISA and histological analysis of liver sections.

RESULTS

The data showed that local administration of antibody therapy eliminated syngeneic murine tumors transplanted in the ear skin at a lower dose than required intravenously, and without measured hepatic toxicity. Tumor elimination was dependent on CD8 T cells and was associated with an increased percentage of CD8 T cells expressing granzyme B, KLRG1 and Eomes, and a decreased population of CD4 T cells including CD4+FoxP3+ cells in the treated tumor microenvironment. Importantly, untreated, distal tumors regressed following antibody treatment of a primary tumor, and immune memory prevented growth of subcutaneous flank tumors administered 50 days after regression of a primary tumor.

CONCLUSIONS

Together, these data suggest that peritumoral immunotherapy for skin tumors offers advantages over conventional intravenous delivery, allowing antibody dose sparing, improved safety and inducing long-term systemic memory. Future clinical trials of immunotherapy for primary skin cancer should focus on peritumoral delivery of combinations of immune checkpoint antibodies.

Delayed vaccine-induced CD8+ T cell expansion by topoisomerase I inhibition mediates enhanced CD70-dependent tumor eradication

BACKGROUND

The survival of patients with cervical cancer who are treated with cisplatin in conjunction with the topoisomerase I inhibitor topotecan is enhanced when compared with patients treated with only one of these chemotherapeutics. Moreover, cisplatin-based and T cell-based immunotherapy have been shown to synergize, resulting in stronger antitumor responses. Here, we interrogated whether topotecan could further enhance the synergy of cisplatin with T cell-based cancer immunotherapy.

METHODS

Mice bearing human papilloma virus 16 (HPV16) E6/E7-expressing TC-1 tumors were vaccinated with HPV16 E7 long peptides and additionally received chemotherapy consisting of cisplatin and topotecan. We performed an in-depth study of this combinatorial chemoimmunotherapy on the effector function and expansion/contraction kinetics of vaccine-induced CD8+ T cells in the peripheral blood and tumor microenvironment (TME). In addition, we interrogated the particular role of chemotherapy-induced upregulation of costimulatory ligands by tumor-infiltrated myeloid cells on T cell proliferation and survival.

RESULTS

We show that E7 long peptide vaccination combined with cisplatin and topotecan, results in CD8+ T cell-dependent durable rejection of established tumors and 94% long-term survival. Although topotecan initially repressed the expansion of vaccine-induced CD8+ T cells, these cells eventually expanded vigorously, which was followed by delayed contraction. These effects associated with the induction of the proliferation marker Ki-67 and the antiapoptosis molecule Bcl-2 by intratumoral tumor-specific CD8+ T cells, which was regulated by topotecan-mediated upregulation of the costimulatory ligand CD70 on myeloid cells in the TME.

CONCLUSIONS

Taken together, our data show that although treatment with cisplatin, topotecan and vaccination initially delays T cell expansion, this combinatorial therapy results eventually in a more robust T cell-mediated tumor eradication due to enhancement of costimulatory molecules in the TME.

Immunotherapies landscape and associated inhibitors for the treatment of cervical cancer

Cervical cancer ranks as the fourth most common form of cancer worldwide. There is a large number of situations that may be examined in the developing world. The risk of contracting HPV (Human Papillomavirus) due to poor sanitation and sexual activity is mostly to blame for the disease's alarming rate of expansion. Immunotherapy is widely regarded as one of the most effective medicines available. The immunotherapy used to treat cervical cancer cells relies on inhibitors that block the immune checkpoint. The poly adenosine diphosphate ribose polymer inhibited cervical cancer cells by activating both the programmed death 1 (PD-1) and programmed death ligand 1 (CTLA-1) checkpoints, a strategy that has been shown to have impressive effects. Yet, immunotherapy directed towards tumors that have already been invaded by lymphocytes leaves a positive imprint on the healing process. Immunotherapy is used in conjunction with other treatments, including chemotherapy and radiation, to provide faster and more effective outcomes. In this combination therapy, several medications such as Pembrolizumab, Durvalumab, Atezolizumab, and so on are employed in clinical trials. Recent developments and future predictions suggest that vaccinations will soon be developed with the dual goal of reducing the patient's susceptibility to illness while simultaneously strengthening their immune system. Many clinical and preclinical studies are now investigating the effectiveness of immunotherapy in slowing the progression of cervical cancer. The field of immunotherapy is expected to witness more progress toward improving outcomes. Immunotherapies landscape and associated inhibitors for the treatment of Cervical Cancer.

Anti-tumor effect of Crocus sativus petals polysaccharides by reconstructing tumor microenvironment

Two polysaccharides from Crocus sativus petals (PCSPs), PCSPA and PCSPB have been previously reported to possess the immunopotentiation activity and improve innate immunity in mice. In this study, PCSPB was evaluated for the anti-tumor activity and explored its immunological mechanisms based on tumor microenvironment (TME) using S180 sarcoma-bearing mice. Although PCSPB showed the lower toxicity to a series of tumor cells, it significantly and dose-dependently suppressed the growth of S180 sarcomas transplanted in mice. HE staining, immunohistochemical analysis, and TUNEL assay revealed that PCSPB significantly induced tumor cell necrosis, apoptosis, and vessel disruption in sarcoma tissues. Meanwhile, PCSPB markedly decreased the levels of inflammatory factors TGF-β, IFN-γ, IL-10 and TNF-α and down-regulated the mRNA expression levels of TGF-β and TNF-α in tumor tissues. Flow cytometric analysis showed that PCSPB significantly increased the proportion of CD8+ T cells and NK cells, but decreased that of regulatory T cells (Tregs), total myeloid-derived suppressor cells (MDSCs), and tumor-associated macrophages (TAMs) in sarcoma tissues. Furthermore, immunofluorescence assay demonstrated that PCSPB noteworthily reprogrammed TAMs from a tumorigenic M2 towards an antitumorigenic M1 phenotype in S180 tissues. These findings demonstrated that PCSPB might exert the anti-tumor activity by reconstructing TME and could act as an anti-tumor candidate with low toxicity.

Unleashing the efficacy of immune checkpoint inhibitors for advanced hepatocellular carcinoma: factors, strategies, and ongoing trials

Hepatocellular carcinoma (HCC) is a prevalent primary liver cancer, representing approximately 85% of cases. The diagnosis is often made in the middle and late stages, necessitating systemic treatment as the primary therapeutic option. Despite sorafenib being the established standard of care for advanced HCC in the past decade, the efficacy of systemic therapy remains unsatisfactory, highlighting the need for novel treatment modalities. Recent breakthroughs in immunotherapy have shown promise in HCC treatment, particularly with immune checkpoint inhibitors (ICIs). However, the response rate to ICIs is currently limited to approximately 15%-20% of HCC patients. Recently, ICIs demonstrated greater efficacy in "hot" tumors, highlighting the urgency to devise more effective approaches to transform "cold" tumors into "hot" tumors, thereby enhancing the therapeutic potential of ICIs. This review presented an updated summary of the factors influencing the effectiveness of immunotherapy in HCC treatment, identified potential combination therapies that may improve patient response rates to ICIs, and offered an overview of ongoing clinical trials focusing on ICI-based combination therapy.

Macrophage's role in solid tumors: two edges of a sword

The tumor microenvironment is overwhelmingly dictated by macrophages, intimately affiliated with tumors, exercising pivotal roles in multiple processes, including angiogenesis, extracellular matrix reconfiguration, cellular proliferation, metastasis, and immunosuppression. They further exhibit resilience to chemotherapy and immunotherapy via meticulous checkpoint blockades. When appropriately stimulated, macrophages can morph into a potent bidirectional component of the immune system, engulfing malignant cells and annihilating them with cytotoxic substances, thus rendering them intriguing candidates for therapeutic targets. As myelomonocytic cells relentlessly amass within tumor tissues, macrophages rise as prime contenders for cell therapy upon the development of chimeric antigen receptor effector cells. Given the significant incidence of macrophage infiltration correlated with an unfavorable prognosis and heightened resistance to chemotherapy in solid tumors, we delve into the intricate role of macrophages in cancer propagation and their promising potential in confronting four formidable cancer variants-namely, melanoma, colon, glioma, and breast cancers.

Chemotherapy postimmunotherapy for recurrent metastatic head and neck squamous cell carcinoma

PURPOSE OF REVIEW

Clinical data on salvage chemotherapy used after checkpoints inhibitors in oncology are reviewed, with a special focus on recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC).

RECENT FINDINGS

Converging evidence is emerging about high response and/or disease control rates associated with salvage chemotherapy after immunotherapy failure in advanced solid tumours. This phenomenon is mainly reported in retrospective studies for "hot tumours" such as R/M HNSCC, melanoma, lung, urothelial or gastric cancers, but also in haematological malignancies. Some physiopathological hypotheses have been raised.

SUMMARY

Several independent series show increased response rates associated with postimmuno chemotherapy when compared with retrospective series in similar settings. Several mechanisms could be involved such as a "carry-over" allowed by a persistence of the checkpoint inhibitor, a modulation of tumour microenvironment components but also an intrinsic immunomodulatory effect of chemotherapy, increased by a specific immunologic state induced by the therapeutic pressure of checkpoint inhibitors. These data establish a rationale for prospectively evaluating the features of postimmunotherapy salvage chemotherapy.

Combination immunotherapy with synthetic long peptides and chemotherapy or PD-1 blocker for cancers caused by human papilloma virus type 16

Therapeutic vaccination of premalignant conditions and of different stages of cancer can be accomplished with several platforms including DNA vaccines, RNA vaccines, synthetic long peptides (SLP), and recombinant viruses. We successfully used a therapeutic vaccine composed of SLP covering the complete sequence of the two oncogenic proteins E6 and E7 of human papillomavirus type 16 (HPV16) as monotherapy in patients with premalignant disease. However, combination treatment might be required in patients with (advanced) cancer because of the hostile cancer microenvironment for T cells in established HPV16+ cancer, often associated with systemic immunosuppression. In patients with late-stage recurrent or metastatic HPV16+ cancers, we have therefore combined treatment with the SLP vaccine, called ISA101b, with either standard-of-care chemotherapy or with immune checkpoint inhibition with anti-PD-1 monoclonal antibody. A strong vaccine-induced interferon gamma-producing T cell response to HPV16 E6/E7 was associated with significantly better survival. In a second phase 1/2 study, patients with recurrent or metastatic HPV16+ oropharyngeal cancer were treated with the combination of ISA101b and anti-PD-1 (nivolumab). In this trial, the clinical overall response rate (ORR) in 22 patients was 36%, twice the ORR in the nivolumab registration trial for this category of patients, and 2/22 patients had a complete clinical response that is ongoing after 4 1/2 years. Other promising strategies for late-stage cancer recipients are the infusion of expanded tumor-infiltrating lymphocytes or the infusion of T cell receptor transduced T cells, both directed against HPV16.

Efficacy and Synergy with Cisplatin of an Adenovirus Vectored Therapeutic E1E2E6E7 Vaccine against HPV Genome-Positive C3 Cancers in Mice

Human papillomavirus (HPV) infections are the main cause of cervical and oropharyngeal cancers. As prophylactic vaccines have no curative effect, an efficient therapy would be highly desired. Most therapeutic vaccine candidates target only a small subset of HPV regulatory proteins, namely, E6 and E7, and are therefore restricted in the breadth of their immune response. However, research has suggested E1 and E2 as promising targets to fight HPV+ cancer. Here, we report the design of adenoviral vectors efficiently expressing HPV16 E1 and E2 in addition to transformation-deficient E6 and E7. Vaccination elicited vigorous CD4+ and CD8+ T-cell responses against all encoded HPV16 proteins in outbred mice and against E1 and E7 in C57BL/6 mice. Therapeutic vaccination of C3 tumor-bearing mice led to significantly reduced tumor growth and enhanced survival for both small and established tumors. Tumor biopsies revealed increased numbers of tumor-infiltrating CD8+ T cells in treated mice. Cisplatin enhanced the effect of therapeutic vaccination, accompanied by enhanced infiltration of dendritic cells into the tumor. CD8+ T cells were identified as effector cells in T-cell depletion assays, seemingly under regulation by FoxP3+CD4+ regulatory T cells. Finally, therapeutic vaccination with Ad-Ii-E1E2E6E7 exhibited significantly enhanced survival compared with vaccination with two peptides each harboring a known E6/E7 epitope. We hypothesize that this difference could be due to the induction of additional T-cell responses against E1. These results support the use of this novel vaccine candidate targeting an extended set of antigens (Ad-Ii-E1E2E6E7), in combination with cisplatin, as an advanced strategy to combat HPV+ cancers.

Necroptosis-dependent Immunogenicity of Cisplatin: Implications for Enhancing the Radiation-induced Abscopal Effect

PURPOSE

Cisplatin is increasingly used in chemoimmunotherapy and may enhance the T cell-dependent radiation-induced abscopal effect, but how it promotes antitumor immunity is poorly understood. We investigated whether and why cisplatin is immunogenic, and the implications for the cisplatin-enhanced abscopal effect.

EXPERIMENTAL DESIGN

Cisplatin, carboplatin, and the well-known immunogenic cell death (ICD) inducer oxaliplatin were compared for their potency to enhance the abscopal effect and induce type I IFN (IFN-I) and extracellular ATP, danger signals of ICD. The hypothetical role of necroptosis and associated damage-associated molecular patterns for cisplatin-induced ICD was investigated by inhibitors and knockout cells in vitro and in two tumor models in mice. A novel necroptosis signature for tumor immune cell infiltration and therapy response was developed.

RESULTS

Cisplatin enhanced the abscopal effect more strongly than oxaliplatin or carboplatin. This correlated with higher induction of IFN-I and extracellular ATP by cisplatin, in a necroptosis-dependent manner. Cisplatin triggered receptor-interacting protein kinase 3 (RIPK3)-dependent tumor cell necroptosis causing cytosolic mitochondrial DNA (mtDNA) release, initiating the cyclic GMP-AMP synthase-stimulator of interferon genes pathway and IFN-I secretion promoting T-cell cross-priming by dendritic cells (DC). Accordingly, tumor cell RIPK3 or mtDNA deficiency and loss of IFN-I or ATP signaling diminished the cisplatin-enhanced abscopal effect. Cisplatin-treated tumor cells were immunogenic in vaccination experiments, depending on RIPK3 and mtDNA. In human tumor transcriptome analysis, necroptotic features correlated with abundant CD8+ T cells/DCs, sparse immunosuppressive cells, and immunotherapy response.

CONCLUSIONS

Cisplatin induces antitumor immunity through necroptosis-mediated ICD. Our findings may help explain the benefits of cisplatin in chemo(radio)immunotherapies and develop clinical trials to investigate whether cisplatin enhances the abscopal effect in patients.

Chemotherapeutics Used for High-Risk Neuroblastoma Therapy Improve the Efficacy of Anti-GD2 Antibody Dinutuximab Beta in Preclinical Spheroid Models

Anti-disialoganglioside GD2 antibody ch14.18/CHO (dinutuximab beta, DB) improved the outcome of patients with high-risk neuroblastoma (HR-NB) in the maintenance phase. We investigated chemotherapeutic compounds used in newly diagnosed patients in combination with DB. Vincristine, etoposide, carboplatin, cisplatin, and cyclophosphamide, as well as DB, were used at concentrations achieved in pediatric clinical trials. The effects on stress ligand and checkpoint expression by neuroblastoma cells and on activation receptors of NK cells were determined by using flow cytometry. NK-cell activity was measured with a CD107a/IFN-γ assay. Long-term cytotoxicity was analyzed in three spheroid models derived from GD2-positive neuroblastoma cell lines (LAN-1, CHLA 20, and CHLA 136) expressing a fluorescent near-infrared protein. Chemotherapeutics combined with DB in the presence of immune cells improved cytotoxic efficacy up to 17-fold compared to in the controls, and the effect was GD2-specific. The activating stress and inhibitory checkpoint ligands on neuroblastoma cells were upregulated by the chemotherapeutics up to 9- and 5-fold, respectively, and activation receptors on NK cells were not affected. The CD107a/IFN-γ assay revealed no additional activation of NK cells by the chemotherapeutics. The synergistic effect of DB with chemotherapeutics seems primarily attributed to the combined toxicity of antibody-dependent cellular cytotoxicity and chemotherapy, which supports further clinical evaluation in frontline induction therapy.

IL-5-producing CD4+ T cells and eosinophils cooperate to enhance response to immune checkpoint blockade in breast cancer

Immune checkpoint blockade (ICB) has heralded a new era in cancer therapy. Research into the mechanisms underlying response to ICB has predominantly focused on T cells; however, effective immune responses require tightly regulated crosstalk between innate and adaptive immune cells. Here, we combine unbiased analysis of blood and tumors from metastatic breast cancer patients treated with ICB with mechanistic studies in mouse models of breast cancer. We observe an increase in systemic and intratumoral eosinophils in patients and mice responding to ICB treatment. Mechanistically, ICB increased IL-5 production by CD4⁺ T cells, stimulating elevated eosinophil production from the bone marrow, leading to systemic eosinophil expansion. Additional induction of IL-33 by ICB-cisplatin combination or recombinant IL-33 promotes intratumoral eosinophil infiltration and eosinophil-dependent CD8⁺ T cell activation to enhance ICB response. This work demonstrates the critical role of eosinophils in ICB response and provides proof-of-principle for eosinophil engagement to enhance ICB efficacy.

Conversion therapy from unresectable stage IIIC non-small-cell lung cancer to radical surgery via anti-PD-1 immunotherapy combined with chemotherapy and anti-angiogenesis: A case report and literature review

The prognosis of patients with stage IIIC non-small-cell lung cancer (NSCLC) is poor due to the loss of surgical treatment opportunities. Improving the prognosis of these patients with IIIC NSCLC urgently needs to be addressed. Here, we report a stage IIIC (T4N3M0 IIIC (AJCC 8th)) NSCLC patient treated with 2 cycles of anti-PD-1 immunotherapy combined with chemotherapy and anti-angiogenesis therapy; after two cycles of treatment, the patient achieved a partial response and obtained the opportunity for surgical treatment. After the operation, the patient achieved a pathological complete response and successfully transformed from unresectable stage IIIC lung cancer to radical surgery (ypT0N0M0). Our study is expected to provide new ideas for treating patients with unresectable stage IIIC NSCLC in the future.

Maximizing the value of phase III trials in immuno-oncology: A checklist from the Society for Immunotherapy of Cancer (SITC)

The broad activity of agents blocking the programmed cell death protein 1 and its ligand (the PD-(L)1 axis) revolutionized oncology, offering long-term benefit to patients and even curative responses for tumors that were once associated with dismal prognosis. However, only a minority of patients experience durable clinical benefit with immune checkpoint inhibitor monotherapy in most disease settings. Spurred by preclinical and correlative studies to understand mechanisms of non-response to the PD-(L)1 antagonists and by combination studies in animal tumor models, many drug development programs were designed to combine anti-PD-(L)1 with a variety of approved and investigational chemotherapies, tumor-targeted therapies, antiangiogenic therapies, and other immunotherapies. Several immunotherapy combinations improved survival outcomes in a variety of indications including melanoma, lung, kidney, and liver cancer, among others. This immunotherapy renaissance, however, has led to many combinations being advanced to late-stage development without definitive predictive biomarkers, limited phase I and phase II data, or clinical trial designs that are not optimized for demonstrating the unique attributes of immune-related antitumor activity-for example, landmark progression-free survival and overall survival. The decision to activate a study at an individual site is investigator-driven, and generalized frameworks to evaluate the potential for phase III trials in immuno-oncology to yield positive data, particularly to increase the number of curative responses or otherwise advance the field have thus far been lacking. To assist in evaluating the potential value to patients and the immunotherapy field of phase III trials, the Society for Immunotherapy of Cancer (SITC) has developed a checklist for investigators, described in this manuscript. Although the checklist focuses on anti-PD-(L)1-based combinations, it may be applied to any regimen in which immune modulation is an important component of the antitumor effect.

The immune modifying effects of chemotherapy and advances in chemo-immunotherapy

Immune checkpoint inhibitors (ICIs) have transformed the treatment paradigm for several malignancies. While the use of single-agent or combined ICIs has achieved acceptable disease control rates in a variety of solid tumors, such approaches have yet to show substantial therapeutic efficacy in select difficult-to-treat cancer types. Recently, select chemotherapy regimens are emerging as extensive modifiers of the tumor microenvironment, leading to the reprogramming of local immune responses. Accordingly, data is now emerging to suggest that certain anti-neoplastic agents modulate various immune cell processes, most notably the cross-presentation of tumor antigens, leukocyte trafficking, and cytokine biosynthesis. As such, the combination of ICIs and cytotoxic chemotherapy are beginning to show promise in many cancers that have long been considered poorly responsive to ICI-based immunotherapy. Here, we discuss past and present attempts to advance chemo-immunotherapy in these difficult-to-treat cancer histologies, mechanisms through which select chemotherapies modify tumor immunogenicity, as well as important considerations when designing such approaches to maximize efficacy and improve therapeutic response rates.

Cancer chemotherapy: insights into cellular and tumor microenvironmental mechanisms of action

Chemotherapy has historically been the mainstay of cancer treatment, but our understanding of what drives a successful therapeutic response remains limited. The diverse response of cancer patients to chemotherapy has been attributed principally to differences in the proliferation rate of the tumor cells, but there is actually very little experimental data supporting this hypothesis. Instead, other mechanisms at the cellular level and the composition of the tumor microenvironment appear to drive chemotherapy sensitivity. In particular, the immune system is a critical determinant of chemotherapy response with the depletion or knock-out of key immune cell populations or immunological mediators completely abrogating the benefits of chemotherapy in pre-clinical models. In this perspective, we review the literature regarding the known mechanisms of action of cytotoxic chemotherapy agents and the determinants of response to chemotherapy from the level of individual cells to the composition of the tumor microenvironment. We then summarize current work toward the development of dynamic biomarkers for response and propose a model for a chemotherapy sensitive tumor microenvironment.

Translational Learnings in the Development of Chemo-Immunotherapy Combination to Bypass the Cold Tumor Microenvironment in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal cancers, with a 5-year relative survival rate of 5%. The desmoplastic stroma found in the tumor microenvironment of PDAC is suggested to be partly responsible for the resistance to most therapeutic strategies. This review outlines the clinical results obtained with an immune checkpoint inhibitor in PDAC and discusses the rationale to use a combination of chemotherapy and immune checkpoint therapy. Moreover, essential parameters to take into account in designing an efficient combination have been highlighted.

Serum Proteomics in Patients with Head and Neck Cancer: Peripheral Blood Immune Response to Treatment

In this real-world study, the aims were to prospectively evaluate the expression of inflammatory proteins in serum collected from head and neck cancer patients before and after treatment, and to assess whether there were differences in expression associated with treatment modalities. The mixed study cohort consisted of 180 patients with head and neck cancer. The most common tumor sites were the oropharynx (n = 81), the oral cavity (n = 53), and the larynx (n = 22). Blood tests for proteomics analysis were carried out before treatment, 7 weeks after the start of treatment, and 3 and 12 months after the termination of treatment. Sera were analyzed for 83 proteins using an immuno-oncology biomarker panel (Olink, Uppsala, Sweden). Patients were divided into four treatment groups: surgery alone (Surg group, n = 24), radiotherapy with or without surgery (RT group, n = 94), radiotherapy with concomitant cisplatin (CRT group, n = 47), and radiotherapy with concomitant targeted therapy (RT Cetux group, n = 15). For the overall cohort, the expression levels of 15 of the 83 proteins changed significantly between the pretreatment sample and the sample taken 7 weeks after the start of treatment. At 7 weeks after the start of treatment, 13 proteins showed lower expression in the CRT group compared to the RT group. The majority of the inflammatory proteins had returned to their pretreatment levels after 12 months. It was clearly demonstrated that cisplatin-based chemoradiation has immunological effects in patients with head and neck cancer. This analysis draws attention to several inflammatory proteins that are of interest for further studies.

Photodynamic therapy using mannose-conjugated chlorin e6 increases cell surface calreticulin in cancer cells and promotes macrophage phagocytosis

Photodynamic therapy (PDT) damages cancer cells via photosensitization using harmless laser irradiation. We synthesized a new photosensitizer, mannose-conjugated-chlorin e6 (M-chlorin e6), which targets mannose receptors that are highly expressed on M2-like tumor-associated macrophages (M2-TAMs) and cancer cells. In our previous study, we demonstrated that M-chlorin e6 PDT reduces tumor volume and decreases the proportion of M2-TAMs. Whether M-chlorin e6 PDT-treated cancer cells activate tumor immunity remains unclear, although the decrease in M2-TAMs is thought to be a direct injurious effect of M-chlorin e6 PDT. Calreticulin (CRT) is exposed at the surface of the membrane of cancer cells in response to treatment with chemotherapeutic agents such as anthracycline and oxaliplatin. Surface-exposed CRT induces phagocytosis of CRT receptor-positive cells, including macrophages, inducing anticancer immune responses. In the present study, we found that M-chlorin e6 PDT increases CRT on the surface of cancer cells, leading to macrophage phagocytosis of cancer cells. Furthermore, M-chlorin e6 PDT increases CD80⁺CD86⁺ macrophages. These results suggest that M-chlorin e6 PDT exerts anti-tumor effects by both enhancing the phagocytosis of cancer cells and strengthening the anti-tumor phenotype of macrophages.

MMP9 Expression Correlates With Cisplatin Resistance in Small Cell Lung Cancer Patients

Background: Cisplatin is the basis of the primary treatment for SCLC chemotherapy. However, the limited objective response rate and definite drug resistance greatly restrict the clinical potential and therapeutic benefits of cisplatin use. Therefore, it is essential to identify biomarkers that can discern the sensitivity of SCLC patients to cisplatin treatment.

Methods: We collected two SCLC cohorts treated with cisplatin that included mutation data, prognosis data and expression data. The sensitivity of cisplatin was evaluated by the pRRophetic algorithm. MCPcounter, quanTIseq, and xCell algorithms were used to evaluate immune cell score. GSEA and ssGSEA algorithms were used to calculate immune-related pathway scores. Univariate and multivariate Cox regression models were employed, and survival analysis was used to evaluate the prognostic value of the candidate genes.

Results: MMP9-High is related to improved clinical prognoses of patients with SCLC (HR = 0.425, p = 0.0085; HR = 0.365, p = 0.0219). Multivariate results showed that MMP-High could be used as an independent predictor of the prognosis of SCLC after cisplatin treatment (HR = 0.216, p = 0.00153; HR = 0.352; p = 0.0199). In addition, MMP9-High displayed a significantly lower IC50 value of cisplatin and higher immunogenicity than MMP9-Low SCLC. Compared with MMP9-Low SCLC, MMP9-High included significantly increased levels of T-cells, cytoxic lymphocytes, B-cells, NK-cells, and dense cells (DCS). Similarly, the activity of cytokine binding, B-cell, NK-cell mediated immune response chemokine binding, and antigen presentation pathways in MMP9-High was significantly higher than that in MMP9-Low.

Conclusion: In this study, we identified that MMP9-High could be potentially considered a novel biomarker used to ascertain the improved prognosis of SCLC patients after cisplatin treatment. Furthermore, we indicated that the tumor immune microenvironment of MMP9-High SCLC is mainly characterized by a large number of infiltrated activated immune cells as well as activated immune-related pathways.

Immunological control of ovarian carcinoma by chemotherapy and targeted anticancer agents

At odds with other solid tumors, epithelial ovarian cancer (EOC) is poorly sensitive to immune checkpoint inhibitors (ICIs), largely reflecting active immunosuppression despite CD8⁺ T cell infiltration at baseline. Accumulating evidence indicates that both conventional chemotherapeutics and targeted anticancer agents commonly used in the clinical management of EOC not only mediate a cytostatic and cytotoxic activity against malignant cells, but also drive therapeutically relevant immunostimulatory or immunosuppressive effects. Here, we discuss such an immunomodulatory activity, with a specific focus on molecular and cellular pathways that can be harnessed to develop superior combinatorial regimens for clinical EOC care.

Identification of an ACK1/TNK2-based prognostic signature for colon cancer to predict survival and inflammatory landscapes

Activated Cdc42-associated kinase 1 (ACK1), a kind of tyrosine kinase, is considered to be an oncogene in many cancers, and it is likely to become a potential target for cancer treatment. We found that the expression of the ACK1 gene in colon cancer was higher than that in normal tissues adjacent to cancer, and high expression of the ACK1 gene was associated with poor prognosis of patients. We assessed the prognosis of colon cancer based on ACK1-related genes and constructed a model that can predict the prognosis of colon cancer patients in colon cancer data from The Cancer Genome Atlas (TCGA) database. We then explored the relationship between ACK1 and the immune microenvironment of colon cancer. The overexpression of ACK1 might hinder the function of antigen-presenting cells. The colon cancer prognosis prediction model we constructed has certain significance for clinicians to judge the prognosis of patients with colon cancer. The expression of the ACK1 gene might affect the infiltration level of a variety of immune cells and immunomodulators in the immune microenvironment.

Infiltrating T lymphocytes in the tumor microenvironment of small cell lung cancer: a state of knowledge review

Immune checkpoint inhibitors (ICIs) have brought new hope for the treatment of patients with small cell lung cancer (SCLC) over the past decades. However, the overall response rate is limited, and is lower than that in non-small cell lung cancer (NSCLC). This is in part because of the lack of pre-existing tumor-infiltrating T lymphocytes (TITLs), especially cytotoxic T cells (CTLs), in the SCLC tumor microenvironment (TME), resulting in insufficient anti-tumor immune response. To unleash the full potential of ICIs, the trafficking and infiltration of TITLs to the tumor is necessary and tightly regulated, the highly immunosuppressive tumor microenvironment blunts the infiltration and function of TITLs that reach the tumor in SCLC. Here, we review the characteristics of TITLs, the effects of various factors on T cell infiltration, and possible strategies to restore or promote T cell infiltration in the TME of SCLC.

Active immunization combined with cisplatin confers enhanced therapeutic protection and prevents relapses of HPV-induced tumors at different anatomical sites

The active immunotherapy concept relies on the use of vaccines that are capable of inducing antitumor immunity, reversion of the suppressive immunological environment, and long-term memory responses. Previously, antitumor vaccines based on a recombinant plasmid (pgDE7h) or a purified protein (gDE7) led to regression of early-established human papillomavirus (HPV)-associated tumors in a preclinical model. In this work, the anticancer vaccines were combined with cisplatin to treat HPV-induced tumors at advanced growth stages. The antitumor effects were evaluated in terms of tumor regression, induction of specific CD8⁺ T cells, and immune modulation of the tumor microenvironment. Acute toxicity induced by the treatment was measured by weight loss and histological alterations in the liver and kidneys. Our results revealed that the combination of cisplatin with either one of the tested immunotherapies (pgDE7h or gDE7) led to complete tumor regression in mice. Also, the combined treatment resulted in synergistic effects, particularly among mice immunized with gDE7, including activation of systemic and tumor-infiltrating E7-specific CD8⁺ T cells, tumor infiltration of macrophages and dendritic cells, and prevention of tumor relapses at different anatomical sites. Furthermore, the protocol allowed the reduction of cisplatin dosage and its intrinsic toxic effects, without reducing antitumor outcomes. These results expand our knowledge of active immunotherapy protocols and open perspectives for alternative treatments of HPV-associated tumors.

Spatial and Temporal Heterogeneity of Tumor-Infiltrating Lymphocytes in Advanced Urothelial Cancer

Checkpoint inhibitors targeting PD-(L)1 induce objective responses in 20% of patients with metastatic urothelial cancer (UC). CD8+ T cell infiltration has been proposed as a putative biomarker for response to checkpoint inhibitors. Nevertheless, data on spatial and temporal heterogeneity of tumor-infiltrating lymphocytes in advanced UC are lacking. The major aims of this study were to explore spatial heterogeneity for lymphocyte infiltration and to investigate how the immune landscape changes during the disease course. We performed multiplex immunohistochemistry to assess the density of intratumoral and stromal CD3+, CD8+, FoxP3+ and CD20+ immune cells in longitudinally collected samples of 49 UC patients. Within these samples, spatial heterogeneity for lymphocyte infiltration was observed. Regions the size of a 0.6 tissue microarray core (0.28 mm2) provided a representative sample in 60.6 to 71.6% of cases, depending on the cell type of interest. Regions of 3.30 mm2, the median tumor surface area in our biopsies, were representative in 58.8 to 73.8% of cases. Immune cell densities did not significantly differ between untreated primary tumors and metachronous distant metastases. Interestingly, CD3+, CD8+ and FoxP3+ T cell densities decreased during chemotherapy in two small cohorts of patients treated with neoadjuvant or palliative platinum-based chemotherapy. In conclusion, spatial heterogeneity in advanced UC challenges the use of immune cell infiltration in biopsies as biomarker for response prediction. Our data also suggests a decrease in tumor-infiltrating T cells during platinum-based chemotherapy.

Exploring the clinical value of tumor microenvironment in platinum-resistant ovarian cancer

Platinum resistance in epithelial ovarian cancer (OvCa) is rising at an alarming rate, with recurrence of chemo-resistant high grade serous OvCa (HGSC) in roughly 75 % of all patients. Additionally, HGSC has an abysmal five-year survival rate, standing at 39 % and 17 % for FIGO stages III and IV, respectively. Herein we review the crucial cellular interactions between HGSC cells and the cellular and non-cellular components of the unique peritoneal tumor microenvironment (TME). We highlight the role of the extracellular matrix (ECM), ascitic fluid as well as the mesothelial cells, tumor associated macrophages, neutrophils, adipocytes and fibroblasts in platinum-resistance. Moreover, we underscore the importance of other immune-cell players in conferring resistance, including natural killer cells, myeloid-derived suppressive cells (MDSCs) and T-regulatory cells. We show the clinical relevance of the key platinum-resistant markers and their correlation with the major pathways perturbed in OvCa. In parallel, we discuss the effect of immunotherapies in re-sensitizing platinum-resistant patients to platinum-based drugs. Through detailed analysis of platinum-resistance in HGSC, we hope to advance the development of more effective therapy options for this aggressive disease.

Dual Targeting of Cancer Cells and MMPs with Self-Assembly Hybrid Nanoparticles for Combination Therapy in Combating Cancer

The co-delivery of chemotherapeutic agents and immune modulators to their targets remains to be a great challenge for nanocarriers. Here, we developed a hybrid thermosensitive nanoparticle (TMNP) which could co-deliver paclitaxel-loaded transferrin (PTX@TF) and marimastat-loaded thermosensitive liposomes (MMST/LTSLs) for the dual targeting of cancer cells and the microenvironment. TMNPs could rapidly release the two payloads triggered by the hyperthermia treatment at the site of tumor. The released PTX@TF entered cancer cells via transferrin-receptor-mediated endocytosis and inhibited the survival of tumor cells. MMST was intelligently employed as an immunomodulator to improve immunotherapy by inhibiting matrix metalloproteinases to reduce chemokine degradation and recruit T cells. The TMNPs promoted the tumor infiltration of CD3+ T cells by 2-fold, including memory/effector CD8+ T cells (4.2-fold) and CD4+ (1.7-fold), but not regulatory T cells. Our in vivo anti-tumor experiment suggested that TMNPs possessed the highest tumor growth inhibitory rate (80.86%) compared with the control group. We demonstrated that the nanoplatform could effectively inhibit the growth of tumors and enhance T cell recruitment through the co-delivery of paclitaxel and marimastat, which could be a promising strategy for the combination of chemotherapy and immunotherapy for cancer treatment.

Gold Compounds and the Anticancer Immune Response

Gold compounds are not only well-explored for cytotoxic effects on tumors, but are also known to interact with the cancer immune system. The immune system deploys innate and adaptive mechanisms to protect against pathogens and prevent malignant transformation. The combined action of gold compounds with the activated immune system has shown promising results in cancer therapy through in vivo and in vitro experiments. Gold compounds are known to induce innate immune responses; however, these responses may contribute to adaptive immune responses. Gold compounds play the role of a major hapten that acts synergistically in innate immunity. Gold compounds support cancer cell antigenicity and promote anti-tumor immune response by inducing the release of CRT, ATP, HMGB1, HSP, and NKG2D to enhance immunogenicity. Gold compounds affect various immune cells (including suppressor regulatory T cells), inhibit myeloid derived suppressor cells, and enhance the function and number of dendritic cells. Gold nanoparticles (AuNPs) have potential for improving the effect of immunotherapy and reducing the toxicity and side effects of the treatment process. Thus, AuNPs provide an ideal opportunity for exploring the combination of anticancer gold compounds and immunotherapeutic interventions.

Immunotherapy for HPV Malignancies

Owing to the presence of known tumor-specific viral antigens, human papillomavirus (HPV)-associated cancers are well suited for treatment with immunotherapy designed to unleash, amplify or replace the T cell arm of the adaptive immune system. Immune checkpoint blockade designed to unleash existing T cell immunity is currently Food and Drug Administration approved for certain HPV-associated cancers. More specific immunotherapies such as therapeutic vaccines and T cell receptor-engineered cellular therapy are currently in clinical development. Such therapies may offer more specific immune activation against viral tumor antigens and decrease the risk of immune-related adverse events. Current and planned clinical study of these treatments will determine their utility in the treatment of patients with newly diagnosed advanced stage or relapsed HPV-associated cancer.

Targeting MDSC for Immune-Checkpoint Blockade in Cancer Immunotherapy: Current Progress and New Prospects

Immune-checkpoint blockade (ICB) demonstrated inspiring effect and great promise in anti-cancer therapy. However, many obstacles, such as drug resistance and difficulty in patient selection, limited the efficacy of ICB therapy and awaited to be overcome. By timely identification and intervention of the key immune-suppressive promotors in the tumor microenvironment (TME), we may better understand the mechanisms of cancer immune-escape and use novel strategies to enhance the therapeutic effect of ICB. Myeloid-derived suppressor cell (MDSC) is recognized as a major immune suppressor in the TME. In this review, we summarized the roles MDSC played in the cancer context, focusing on its negative biologic functions in ICB therapy, discussed the strategies targeted on MDSC to optimize the diagnosis and therapy process of ICB and improve the efficacy of ICB therapy against malignancies.

Investigating Optimal Chemotherapy Options for Osteosarcoma Patients through a Mathematical Model

Simple Summary

Osteosarcoma is a rare type of cancer with poor prognoses. However, to the best of our knowledge, there are no mathematical models that study the impact of chemotherapy treatments on the osteosarcoma microenvironment. In this study, we developed a data driven mathematical model to analyze the dynamics of the important players in three groups of osteosarcoma tumors with distinct immune patterns in the presence of the most common chemotherapy drugs. The results indicate that the treatments’ start times and optimal dosages depend on the unique growth rate of the tumor, which implies the necessity of personalized medicine. Furthermore, the developed model can be extended by others to build models that can recommend individual-specific optimal dosages.

Abstract

Since all tumors are unique, they may respond differently to the same treatments. Therefore, it is necessary to study their characteristics individually to find their best treatment options. We built a mathematical model for the interactions between the most common chemotherapy drugs and the osteosarcoma microenvironments of three clusters of tumors with unique immune profiles. We then investigated the effects of chemotherapy with different treatment regimens and various treatment start times on the behaviors of immune and cancer cells in each cluster. Saliently, we suggest the optimal drug dosages for the tumors in each cluster. The results show that abundances of dendritic cells and HMGB1 increase when drugs are given and decrease when drugs are absent. Populations of helper T cells, cytotoxic cells, and IFN-γ grow, and populations of cancer cells and other immune cells shrink during treatment. According to the model, the MAP regimen does a good job at killing cancer, and is more effective than doxorubicin and cisplatin combined or methotrexate alone. The results also indicate that it is important to consider the tumor’s unique growth rate when deciding the treatment details, as fast growing tumors need early treatment start times and high dosages.

Tumor-Associated Macrophages (TAMs) in Colorectal Cancer (CRC): From Mechanism to Therapy and Prognosis

Colorectal cancer (CRC) is a malignant tumor in the digestive system whose incidence and mortality is high-ranking among tumors worldwide. The initiation and progression of CRC is a complex process involving genetic alterations in cancer cells and multiple factors from the surrounding tumor cell microenvironment. As accumulating evidence has shown, tumor-associated macrophages (TAMs)—as abundant and active infiltrated inflammatory cells in the tumor microenvironment (TME)—play a crucial role in CRC. This review focuses on the different mechanisms of TAM in CRC, including switching of phenotypical subtypes; promoting tumor proliferation, invasion, and migration; facilitating angiogenesis; mediating immunosuppression; regulating metabolism; and interacting with the microbiota. Although controversy remains in clinical evidence regarding the role of TAMs in CRC, clarifying their significance in therapy and the prognosis of CRC may shed new light on the optimization of TAM-centered approaches in clinical care.

Novel immunomodulatory properties of low dose cytarabine entrapped in a mannosylated cationic liposome

Cancer treatment remains unsatisfactory with high rates of recurrence and metastasis. Immunomodulatory agents capable of promoting cellular antitumor immunity while inhibiting the local immunosuppressive tumor microenvironment could greatly improve cancer treatment. We have developed a multi-targeted mannosylated cationic liposome delivery system containing muramyl dipeptide (DS) and low doses of the chemotherapeutic agent cytarabine (Ara-C). Immunomodulation of primary immune cells and immortalized cancer cell lines by Ara-C/DS was assessed by measuring cytokine levels and surface marker expression. As a proof of concept, the generation of targeted cellular immunity was investigated in the context of responses to viral antigens. This report is the first demonstrating that Ara-C combined with DS can modulate immune responses and revert immunosuppression as evidenced by increased IFN-γ and IL-12p40 without changes in IL-10 in peripheral blood mononuclear cells, and increased CD80 and decreased CD163 on immunosuppressive macrophages. Furthermore, Ara-C/DS increased MHC class I expression on cancer cells while increasing the production of antigen-specific IFN-γ⁺ CD8⁺ T cells in viral peptide-challenged lymphocytes from both humans and vaccinated mice. Taken together, these results are the first to document immunomodulatory properties of Ara-C linked with recognition of antigens and potentially the generation of antitumor immune memory.

Intra-arterial infusion chemotherapy utilizing cisplatin inhibits bladder cancer by decreasing the fibrocytic myeloid-derived suppressor cells in an m6A-dependent manner

Intra-arterial infusion chemotherapy (IAIC), using immunomodulatory cisplatin, is a novel treatment for bladder cancer (BC) that allows the delivery of specific drugs to the local malignant lesion. To explore the immunomodulatory effect of cisplatin during IAIC, we detected the proportion of immunosuppressed cells in BC tissue from eight BC patients, with the reduction of myeloid-derived suppressor cells (MDSCs), more specifically fibrocytic-MDSCs (f-MDSCs). Further, we demonstrated that cisplatin inhibits their proliferation and immunosuppressive activity. f-MDSCs promote tumor proliferation and metastasis in the BC immune environment. Then, we analyzed the genetic differences detected in samples before and after chemotherapy and found that granulocyte colony-stimulating factors (G-CSF) decreased after IAIC. Furthermore, G-CSF methylation decreased following treatment with cisplatin. Specifically, treatment with cisplatin decreased the methylase (METTL3) levels in BC cells, which is important for G-CSF production. Collectively, cisplatin decreased the number of f-MDSCs during IAIC, by blocking G-CSF methylation via targeting METTL3.

Strong vaccine responses during chemotherapy are associated with prolonged cancer survival

Therapeutic cancer vaccines have effectively induced durable regressions of premalignant oncogenic human papilloma virus type 16 (HPV16)-induced anogenital lesions. However, the treatment of HPV16-induced cancers requires appropriate countermeasures to overcome cancer-induced immune suppression. We previously showed that standard-of-care carboplatin/paclitaxel chemotherapy can reduce abnormally high numbers of immunosuppressive myeloid cells in patients, allowing the development of much stronger therapeutic HPV16 vaccine (ISA101)-induced tumor immunity. We now show the clinical effects of ISA101 vaccination during chemotherapy in 77 patients with advanced, recurrent, or metastatic cervical cancer in a dose assessment study of ISA101. Tumor regressions were observed in 43% of 72 evaluable patients. The depletion of myeloid suppressive cells by carboplatin/paclitaxel was associated with detection of low frequency of spontaneous HPV16-specific immunity in 21 of 62 tested patients. Patients mounted type 1 T cell responses to the vaccine across all doses. The group of patients with higher than median vaccine-induced immune responses lived longer, with a flat tail on the survival curve. This demonstrates that chemoimmunotherapy can be exploited to the benefit of patients with advanced cancer based on a defined mode of action.

Avelumab first-line maintenance in locally advanced or metastatic urothelial carcinoma: Applying clinical trial findings to clinical practice

Although urothelial carcinoma (UC) is considered a chemotherapy-sensitive tumor, progression-free survival and overall survival (OS) are typically short following standard first-line (1L) platinum-containing chemotherapy in patients with locally advanced or metastatic disease. Immune checkpoint inhibitors (ICIs) have antitumor activity in UC and favorable safety profiles compared with chemotherapy; however, trials of 1L ICI monotherapy or chemotherapy + ICI combinations have not yet shown improved OS vs chemotherapy alone. In addition to direct cytotoxicity, chemotherapy has potential immunogenic effects, providing a rationale for assessing ICIs as switch-maintenance therapy. In the JAVELIN Bladder 100 phase 3 trial, avelumab administered as 1L maintenance with best supportive care (BSC) significantly prolonged OS vs BSC alone in patients with locally advanced or metastatic UC that had not progressed with 1L platinum-containing chemotherapy (median OS, 21.4 vs 14.3 months; hazard ratio, 0.69 [95% CI, 0.56-0.86]; P = 0.001). Efficacy benefits were seen across various subgroups, including recipients of 1L cisplatin- or carboplatin-based chemotherapy, patients with PD-L1+ or PD-L1- tumors, and patients with diverse characteristics. Results from JAVELIN Bladder 100 led to the approval of avelumab as 1L maintenance therapy for patients with locally advanced or metastatic UC that has not progressed with platinum-containing chemotherapy. Avelumab 1L maintenance is also included as a standard of care in treatment guidelines for advanced UC with level 1 evidence. This review summarizes the data that supported these developments and discusses practical considerations for administering avelumab maintenance in clinical practice, including patient selection and treatment management.

Resistance to Immune Checkpoint Blockade in Uterine Leiomyosarcoma: What Can We Learn from Other Cancer Types?

The onset of immune checkpoint blockade (ICB) therapy over the last decade has transformed the therapeutic landscape in oncology. ICB has shown unprecedented clinical activity and durable responses in a variety of difficult-to-treat cancers. However, despite these promising long-term responses, a majority of patients fail to respond to single-agent therapy, demonstrating primary or acquired resistance. Uterine leiomyosarcoma (uLMS) is a rare high-risk gynecological cancer with very limited treatment options. Despite research indicating a strong potential for ICB in uLMS, a clinical trial assessing the response to immunotherapy with single-agent nivolumab in advanced-stage uLMS showed no clinical benefit. Many mechanisms of resistance to ICB have been characterized in a variety of tumor types, and many more continue to be uncovered. However, the mechanisms of resistance to ICB in uLMS remain largely unexplored. By elucidating and targeting mechanisms of resistance, treatments can be tailored to improve clinical outcomes. Therefore, in this review we will explore what is known about the immunosuppressive microenvironment of uLMS, link these data to possible resistance mechanisms extrapolated from other cancer types, and discuss potential therapeutic strategies to overcome resistance.