Summary Immune checkpoint therapy to reverse natural killer (NK) and T cell exhaustion has emerged as a promising treatment in various cancers. While anti‐programmed cell death 1 (PD‐1) pembrolizumab has recently gained Food and Drug Administration (FDA) approval for use in recurrent or metastatic cervical cancer, other checkpoint molecules, such as T cell immunoreceptor with immunoglobulin (Ig) and immunoreceptor tyrosine‐based inhibition motif (ITIM) domains (TIGIT) and T cell immunoglobulin and mucin‐domain containing‐3 (Tim‐3), have yet to be fully explored in this disease. We report expression of TIGIT, Tim‐3 and PD‐1 on subsets of peripheral blood NK (CD56dim/negCD16bright/dim/neg and CD56brightCD16dim/neg) and T cells. The percentages of these cells were increased in women with cervical cancer and pre‐malignant lesions. PD‐1+ NK and T cells were likely to co‐express TIGIT and/or Tim‐3. These cells, with an apparently ‘exhausted’ phenotype, were augmented in patients. A subset of cells were also natural killer group 2 member D (NKG2D)‐ and DNAX accessory molecule 1 (DNAM‐1)‐positive. PD‐1int and PD‐1high T cells were notably increased in cervical cancer. Soluble programmed cell death ligand 1 (PD‐L1) was higher in cancer patient blood versus healthy donors and we observed a positive correlation between sPD‐L1 and PD‐1+ T cells in women with low‐grade lesions. Within the cancer group, there were no significant correlations between sPD‐L1 levels and cervical cancer stage. However, when comparing cancer versus healthy donors, we observed an inverse association between sPD‐L1 and total T cells and a correlation between sPD‐L1 and CD56dim NK cells. Our results may show an overview of the immune response towards pre‐cancerous lesions and cervical cancer, perhaps giving an early clue as to whom to administer blocking therapies. The increase of multiple checkpoint markers may aid in identifying patients uniquely responsive to combined antibody therapies.

BackgroundCervical cancer continues to be a major public health problem worldwide, and Cisplatin is used as first-line chemotherapy for this cancer; however, malignant cells exposed to CISplatin (CIS) become insensitive to the effects of this drug. PenToXifylline (PTX) is a xanthine that sensitizes several types of tumor cells to apoptosis induced by antitumor drugs, such as Adriamycin, Carboplatin, and CIS. The effects of PTX on tumor cells have been related to the disruption of the NF-κB pathway, thus preventing the activation of cell survival mechanisms such as the expression of anti-apoptotic genes, the secretion of proinflammatory interleukins, and growth factors.ObjectiveIn this work, we studied the antitumor proprieties of PTX in human SiHa cervical carcinoma cells resistant to CIS.Materials and MethodsSiHa and HeLa cervical cancer cells and their CIS-resistant derived cell lines (SiHaCIS-R and HeLaCIS-R, respectively) were used as in-vitro models. We studied the effects of PTX alone or in combination with CIS on cell viability, apoptosis, caspase-3, caspase-8, and caspase-9 activity, cleaved PARP-1, anti-apoptotic protein (Bcl-2 and Bcl-xL) levels, p65 phosphorylation, cadmium chloride (CdCl2) sensitivity, Platinum (Pt) accumulation, and glutathione (GSH) levels, as well as on the gene expression of GSH and drug transporters (influx and efflux).ResultsPTX sensitized SiHaCIS-R cells to the effects of CIS by inducing apoptosis, caspase activation, and PARP-1 cleavage. PTX treatment also decreased p65 phosphorylation, increased Pt levels, depleted GSH, and downregulated the expression of the ATP7A, ATP7B, GSR, and MGST1 genes.ConclusionPTX reverses the acquired phenotype of CIS resistance close to the sensitivity of parental SiHa cells.

Breast cancer is the most frequent cancer in women worldwide, and drug resistance is common in all breast cancer types. The combination of natural products with chemotherapies has attracted attention, as it was found that natural compounds enhance the effects of standard cancer chemotherapeutic drugs and protect from side effects. Into the different natural products, garlic has been recognized for its antitumor properties. It is suggested that its anticancer effects are associated with its organo‐sulfur compounds, especially alliin and allicin. Here, we evaluated the effects of both molecules on cell death, senescence, and their senolytic potential in luminal A and triple‐negative breast cancer cells. MCF‐7 (luminal A) and HCC‐70 (triple‐negative) cells were cultured and treated with different concentrations of alliin or allicin. Then, cell viability was determined using the WST‐1 reagent. Apoptosis and caspase activity were evaluated by flow cytometry; ΔΨm was assessed using a JC‐10 fluorometric assay kit. Apoptosis‐related genes were evaluated by RT‐PCR. Proliferation was measured using bromodeoxyuridine incorporation. We also evaluated clonogenicity, senescence (β‐Galactosidase Staining), and the senolytic effect of the compounds. Our results showed that allicin has antiproliferative, anticlonogenic, and senolytic effects. In addition, allicin decreased cell viability and induced apoptosis by loss of ΔΨm, caspase‐3, caspase‐8, and caspase‐9 activation, upregulation of NOXA, P21, and BAK, as well as downregulation of BCL‐XL expression. Contrary to allicin, alliin promoted clonogenicity, induced senescence, and did not exhibit pro‐apoptotic effects in breast cancer cells.

Prostate cancer (PCa) is a key public health problem worldwide; at diagnosis, a high percentage of patients exhibit tumor cell invasion of adjacent tissue. STAT-3, IL-6 receptor (R) and IL-6 serum levels are associated with enhanced PCa migratory, invasive, clonogenic and metastatic ability. Inhibiting the STAT-3 pathway at different levels (cytokines, receptors, and kinases) exhibits relative success in cancer. The present study investigated the effect of Stattic (Stt) + Tocilizumab (Tcz) on proliferative, clonogenic, migratory and invasive ability of human metastatic PCa (assessed by colony formation, wound healing and migration assay). RWPE-1 (epithelial prostate immortalized cells), 22Rv1 (Tumor cells), LNCaP (Metastatic cells) and DU-145 (metastatic, castration-resistant prostate cells) cells were used in vitro to evaluate levels of cytokines, chemokines, growth factors (Cytometric Bead Array), STAT-3, phosphorylated STAT-3 (In-Cell Western), IL-6R, vimentin and epithelial (E-) cadherin (Western Blot). The effect of inhibition of STAT-3 (expressed constitutively in DU-145 cells) with Stt and/or Tcz on expression levels of vimentin, VEGF, and E-cadherin, as well as proliferative, clonogenic, migratory and invasive capacity of metastatic PCa cells was assessed. The expression levels of IL-6, C-X-C chemokine ligand 8, VEGF and vimentin, as well as proliferation and migration, were increased in metastatic PCa cells. Treatment with Stt or Tcz decreased vimentin and VEGF and increased E-cadherin expression levels and inhibited proliferative, clonogenic, migratory and invasive capacity of DU-145 cells; addition of IL-6 decreased this inhibitory effect. However, Stt + Tcz maintained inhibition even in the present of high concentrations of IL-6. Stt + Tcz decreased expression of vimentin and VEGF and inhibited the proliferative, clonogenic, migratory and invasive capacity of metastatic PCa cells. To the best of our knowledge, the present study is the first to combine Stt, a STAT-3 inhibitor, with Tcz, an antibody against IL-6R, to target tumor cells.

Background Although great progress has been made in treatment regimens, cervical cancer remains as one of the most common cancer in women worldwide. Studies focusing on molecules that regulate carcinogenesis may provide potential therapeutic strategies for cervical cancer. B7-H6, an activating immunoligand expressed by several tumor cells, is known to activate NK cell-mediated cytotoxicity once engaged with its natural receptor NKp30. However, the opposite, that is, the effects in the tumor cell triggered by B7-H6 after interacting with NKp30 has not yet been well explored. Methods In this study, we evaluated the surface expression of B7-H6 by flow cytometry. Later, we stimulated B7-H6 positive cervical cancer derived-cell lines (HeLa and SiHa) with recombinant soluble NKp30 (sNKp30) protein and evaluated biological effects using the impedance RTCA system for cell proliferation, the scratch method for cell migration, and flow cytometry for apoptosis. Cellular localization of B7-H6 was determined using confocal microscopy. Results Notably, we observed that the addition of sNKp30 to the cervical cancer cell lines decreased tumor cell proliferation and migration rate, but had no effect on apoptosis. We also found that B7-H6 is selectively maintained in tumor cell lines, and that efforts to sort and purify B7-H6 negative or positive cells were futile, as negative cells, when cultured, regained the expression of B7-H6 and B7-H6 positive cells, when sorted and cultivated, lost a percentage of B7-H6 expression. Conclusions Our results suggest that B7-H6 has an important, as of yet undescribed, role in the biology of the cervical tumor cells themselves, suggesting that this protein might be a promising target for anti-tumor therapy in the future.