CXCL8 Facilitates the Survival and Paclitaxel-Resistance of Triple-Negative Breast Cancers

Additional expression of T-cell engager in clinically tested oncolytic adeno-immunotherapy redirects tumor-infiltrated, irrelevant T cells against cancer cells to enhance antitumor immunity

BACKGROUND

Oncolytic adenoviruses (OAds) are the most clinically tested viral vectors for solid tumors. However, most clinically tested "Armed" OAds show limited antitumor effects in patients with various solid tumors even with increased dosages and multiple injections. We developed a binary oncolytic/helper-dependent adenovirus system (CAdVEC), in which tumors are coinfected with an OAd and a non-replicating helper-dependent Ad (HDAd). We recently demonstrated that a single low-dose CAdVEC expressing interleukin-12, programmed death-ligand 1 blocker, and HSV thymidine kinase safety switch (CAdTrio) induces significant antitumor effects in patients, including complete response. Similar to previous OAd studies, all patients primarily amplified Ad-specific T cells after treatment however, CAdVEC was still able to induce clinical responses even given at a 100-fold lower dose.

METHODS

To address the mechanisms of CAdTrio-mediated antitumor effect in patients, we analyzed patients' samples using Enzyme-linked immunosorbent spot (ELISpot) to measure T-cell specificity and quantitative polymerase chain reaction (qPCR) to measure CAdVEC viral genome copies at tumor sites. We then evaluated potential mechanisms of CAdVEC efficacy in vitro using live-cell imaging. Based on those results, we developed a new CAdVEC additionally expressing a T-cell engager molecule targeting CD44v6 to redirect tumor-infiltrating irrelevant T cells against cancer stem cell populations (CAdTetra) for further improvement of local CAdVEC treatment. We tested its efficacy against different cancer types both in vitro and in vivo including Ad pre-immunized humanized mice.

RESULTS

We found that HDAd-infected cells escape Ad-specific T-cell recognition with enhanced tumor-specific T-cell activity through immunomodulatory transgenes. Since CAdVEC treatment initially amplified Ad-specific T cells in patients, we re-direct these virus-specific T cells to target tumor cells by additionally expressing CD44v6.BiTE from CAdTetra. CAdTetra significantly controlled tumor growth, repolarizing local and systemic responses against cancer cells in both immunologically "hot" and "cold" tumor models and also induced immunologic memory against rechallenged tumors.

CONCLUSIONS

Our results indicate that CAdTetra effectively induces adaptive T-cell responses against cancer cells by using tumor-infiltrating irrelevant T cells.

Immunosuppressive SOX9-AS1 Resists Triple-Negative Breast Cancer Senescence Via Regulating Wnt Signalling Pathway

Long noncoding RNAs (lncRNAs) are involved in the regulation of triple-negative breast cancer (TNBC) senescence, while pro-carcinogenic lncRNAs resist senescence onset leading to the failure of therapy-induced senescence (TIS) strategy, urgently identifying the key senescence-related lncRNAs (SRlncRNAs). We mined seven SRlncRNAs (SOX9-AS1, LINC01152, AC005152.3, RP11-161 M6.2, RP5-968 J1.1, RP11-351 J23.1 and RP11-666A20.3) by bioinformatics, of which SOX9-AS1 was reported to be pro-carcinogenic. In vitro experiments revealed the highest expression of SOX9-AS1 in MDA-MD-231 cells. SOX9-AS1 knockdown inhibited cell growth (proliferation, cycle and apoptosis) and malignant phenotypes (migration and invasion), while SOX9-AS1 overexpression rescued these effects. Additionally, SOX9-AS1 knockdown facilitated tamoxifen-induced cellular senescence and the transcription of senescence-associated secretory phenotype (SASP) factors (IL-1α, IL-1β, IL-6 and IL-8) mechanistically by resisting senescence-induced Wnt signal (GSK-3β/β-catenin) activation. Immune infiltration analysis revealed that low SOX9-AS1 expression was accompanied by a high infiltration of naïve B cells, CD8+ T cells and γδ T cells. In conclusion, SOX9-AS1 resists TNBC senescence via regulating the Wnt signalling pathway and inhibits immune infiltration. Targeted inhibition of SOX9-AS1 enhances SASP and thus mobilises immune infiltration to adjunct TIS strategy.

Bioinformatics approach combined with experimental verification reveals OAS3 gene implicated in paclitaxel resistance in head and neck cancer

BACKGROUND

This study aimed to identify a candidate gene associated with paclitaxel (PTX) resistance and to evaluate functionally its biological role in the PTX-resistant head and neck squamous cell carcinoma (HNSCC) cell lines and clinical specimens.

METHODS

Microarray data series containing samples of different types of cancers resistant to PTX were analyzed and then a candidate gene associated with PTX resistance was identified using various bioinformatics tools. After the suppression of the target gene expression, changes in cell viability and colony-forming ability were evaluated in PTX-resistant FaDu and SCC-9 cell lines.

RESULTS

Bioinformatics analyses of upregulated genes in PTX-resistant cancer cells indicated that OAS3 was associated with PTX resistance. The downregulation of OAS3 expression significantly reduced the viability and colony-forming capacity of PTX-resistant SCC-9 cells by inducing apoptosis and cell cycle arrest at G0/G1 phase.

CONCLUSIONS

The therapeutic targeting of OAS3 may resensitize PTX-resistant HNSCC cells with high OAS3 expression to PTX treatment.

Cancer stem cell-mediated drug resistance: A comprehensive gene expression profile analysis in breast cancer

Breast cancer is the most frequently diagnosed malignancy in women and a major public health concern. In the current report, differential expression of the breast cancer resistance promoting genes with a focus on breast cancer stem cell related elements as well as the correlation of their mRNAs with various clinicopathologic characteristics, including molecular subtypes, tumor grade/stage, and methylation status, have been investigated using METABRIC and TCGA datasets. To achieve this goal, we downloaded gene expression data of breast cancer patients from TCGA and METABRIC. Then, statistical analyses were used to assess the correlation between the expression levels of stem cell related drug resistant genes and methylation status, tumor grades, various molecular subtypes, and some cancer hallmark gene sets such as immune evasion, metastasis, and angiogenesis. According to the results of this study, a number of stem cell related drug resistant genes are deregulated in breast cancer patients. Furthermore, we observe negative correlations between methylation of resistance genes and mRNA expression. There is a significant difference in the expression of resistance-promoting genes between different molecular subtypes. As mRNA expression and DNA methylation are clearly related, DNA methylation might be a mechanism that regulates these genes in breast cancer cells. As indicated by the differential expression of resistance-promoting genes among various breast cancer molecular subtypes, these genes may function differently in different subtypes of breast cancer. In conclusion, significant deregulation of resistance-promoting factors indicates that these genes may play a significant role in the development of breast cancer.

Paclitaxel and docetaxel resistance in prostate cancer: Molecular mechanisms and possible therapeutic strategies

Prostate cancer is among most malignant tumors around the world and this urological tumor can be developed as result of genomic mutations and their accumulation during progression towards advanced stage. Due to lack of specific symptoms in early stages of prostate cancer, most cancer patients are diagnosed in advanced stages that tumor cells display low response to chemotherapy. Furthermore, genomic mutations in prostate cancer enhance the aggressiveness of tumor cells. Docetaxel and paclitaxel are suggested as well-known compounds for chemotherapy of prostate tumor and they possess a similar function in cancer therapy that is based on inhibiting depolymerization of microtubules, impairing balance of microtubules and subsequent delay in cell cycle progression. The aim of current review is to highlight mechanisms of paclitaxel and docetaxel resistance in prostate cancer. When oncogenic factors such as CD133 display upregulation and PTEN as tumor-suppressor shows decrease in expression, malignancy of prostate tumor cells enhances and they can induce drug resistance. Furthermore, phytochemicals as anti-tumor compounds have been utilized in suppressing chemoresistance in prostate cancer. Naringenin and lovastatin are among the anti-tumor compounds that have been used for impairing progression of prostate tumor and enhancing drug sensitivity. Moreover, nanostructures such as polymeric micelles and nanobubbles have been utilized in delivery of anti-tumor compounds and decreasing risk of chemoresistance development. These subjects are highlighted in current review to provide new insight for reversing drug resistance in prostate cancer.

Exploring the Characteristics of Monkeypox-Related Genes in Pan-Cancer

Monkeypox, an infectious virus that is a member of the Poxviridae family, has raised great threats to humans. Compared to the known oncoviruses, the relationship between monkeypox and cancer still remains obscure. Hence, in this study, we analyzed the multi-omics data from the Cancer Genome Atlas (TCGA) database by using genomic and transcriptomic approaches to comprehensively assess the monkeypox-related genes (MRGs) in tumor samples from 33 types of cancers. Based on the results, the expression of MRGs was highly correlated with the immune infiltration and could be further utilized to predict survival in cancer patients. Furthermore, it was shown that tumorigenesis and patient survival were frequently associated with the genomic alterations of MRGs. Moreover, pathway analysis showed that MRGs participated in the regulation of apoptosis, cell cycle, Epithelial to Mesenchymal Transition (EMT), DNA damage, and hormone androgen receptor (AR), as well as RAS/MAPK and RTK signaling pathways. Besides, we also developed the prognostic features and consensus clustering clusters of MRGs in cancers. Lastly, by mining the cancer drug sensitivity genomics database, we further identified a series of candidate drugs that may target MRGs. Collectively, this study revealed genomic alterations and clinical features of MRGs, which may provide new hints to explore the potential molecular mechanisms between viruses and cancers as well as to provide new clinical guidance of cancer patients who also face the threats during the monkeypox epidemic.

Chemokines in the Landscape of Cancer Immunotherapy: How They and Their Receptors Can Be Used to Turn Cold Tumors into Hot Ones?

Over the last decade, monoclonal antibodies to immune checkpoint inhibitors (ICI), also known as immune checkpoint blockers (ICB), have been the most successful approach for cancer therapy. Starting with mAb to cytotoxic T lymphocyte antigen 4 (CTLA-4) inhibitors in metastatic melanoma and continuing with blockers of the interactions between program cell death 1 (PD-1) and its ligand program cell death ligand 1 (PDL-1) or program cell death ligand 2 (PDL-2), that have been approved for about 20 different indications. Yet for many cancers, ICI shows limited success. Several lines of evidence imply that the limited success in cancer immunotherapy is associated with attempts to treat patients with "cold tumors" that either lack effector T cells, or in which these cells are markedly suppressed by regulatory T cells (Tregs). Chemokines are a well-defined group of proteins that were so named due to their chemotactic properties. The current review focuses on key chemokines that not only attract leukocytes but also shape their biological properties. CXCR3 is a chemokine receptor with 3 ligands. We suggest using Ig-based fusion proteins of two of them: CXL9 and CXCL10, to enhance anti-tumor immunity and perhaps transform cold tumors into hot tumors. Potential differences between CXCL9 and CXCL10 regarding ICI are discussed. We also discuss the possibility of targeting the function or deleting a key subset of Tregs that are CCR8+ by monoclonal antibodies to CCR8. These cells are preferentially abundant in several tumors and are likely to be the key drivers in suppressing anti-cancer immune reactivity.