The dynamin-related protein Opa1 is localized to the mitochondrial intermembrane space, where it facilitates fusion between mitochondria. Apoptosis causes Opa1 release into the cytosol and causes ...mitochondria to fragment. Loss of mitochondrial membrane potential also causes mitochondrial fragmentation but not Opa1 release into the cytosol. Both conditions induce the proteolytic cleavage of Opa1, suggesting that mitochondrial fragmentation is triggered by Opa1 inactivation. The opposite effect was observed with knockdown of the mitochondrial intermembrane space protease Yme1. Knockdown of Yme1 prevents the constitutive cleavage of a subset of Opa1 splice variants but does not affect carbonyl cyanide m-chlorophenyl hydrazone or apoptosis-induced cleavage. Knockdown of Yme1 also increases mitochondrial connectivity, but this effect is independent of Opa1 because it also occurs in Opa1 knockdown cells. We conclude that Yme1 constitutively regulates a subset of Opa1 isoforms and an unknown mitochondrial morphology protein, whereas the loss of membrane potential induces the further proteolysis of Opa1.
Bacterial flora has clinical significance for the host. The metabolic environment created by this flora influences immunotherapy in urothelial carcinoma. However, there are no reports on the clinical ...significance of bacterial flora in the host bloodstream. We aimed to clarify the correlation between extracellular vesicle (EV)-derived blood microflora information and tumor immunological status in urothelial carcinoma (UC) patients. Serum samples were collected from 20 healthy donors, 50 patients with localized UC, and 31 patients with metastatic UC (mUC) who had undergone pembrolizumab treatment. Bacterial DNA in EVs was extracted from each sample. Metagenomic sequencing was performed after amplification of the V1–V2 region of the bacterial 16S rRNA gene. Using the matched tumor tissue and serum samples, we revealed that the smaller amount of peripheral EVs carrying Firmicutes DNA was significantly correlated with the higher number of infiltrating T cells within tumor tissues (CD3;
p
= 0.015, CD4;
p
= 0.039, CD8;
p
= 0.0084) and the higher expression of activation markers on their surface (ICOS on both CD4;
p
= 0.0013 and CD8 T cells;
p
= 0.016 and 4-1BB on CD4 T cells;
p
= 0.016). In terms of circulating metabolic information,
l
-Ser and
l
-Pro levels, which play important roles in T cell expansion and proliferation, were significantly higher in the Firmicutes-low group (
p
= 0.010). All of the patients with higher Firmicutes abundance had disease progression without any clinical response (
p
= 0.026) and significantly inferior prognosis for pembrolizumab therapy (
p
= 0.035). This is the first study on the importance of peripheral bacterial EVs in cancer patients treated with cancer immunotherapy.
Robust induction of cancer-antigen-specific CD8
T cells is essential for the success of cancer peptide vaccines, which are composed of a peptide derived from a cancer-specific antigen and an ...immune-potentiating adjuvant, such as a Toll-like receptor (TLR) agonist. Efficient delivery of a vaccine antigen and an adjuvant to antigen-presenting cells in the draining lymph nodes (LNs) holds key to maximize vaccine efficacy. Here, we developed S-540956, a novel TLR9-agonistic adjuvant consisting of B-type CpG ODN2006 (also known as CpG7909), annealed to its complementary sequence oligodeoxynucleotide (ODN) conjugated to a lipid; it could target both a cancer peptide antigen and a CpG-adjuvant in the draining LNs. S-540956 accumulation in the draining LNs and activation of plasmacytoid dendritic cells (pDCs) were significantly higher than that of ODN2006. Mechanistic analysis revealed that S-540956 enhanced the induction of MHC class I peptide-specific CD8
T cell responses
TLR9 in a CD4
T cell-independent manner. In mice, the therapeutic effect of S-540956-adjuvanted with a human papillomavirus (HPV)-E7 peptide vaccine against HPV-E7-expressing TC-1 tumors was significantly better than that of an ODN2006-adjuvanted vaccine. Our findings demonstrate a novel adjuvant discovery with the complementary strand conjugated to a lipid, which enabled draining LN targeting and increased ODN2006 accumulation in draining LNs, thereby enhancing the adjuvant effect. Our findings imply that S-540956 is a promising adjuvant for cancer peptide vaccines and has a high potential for applications in various vaccines, including recombinant protein vaccines.
It is important to evaluate the clinical importance of both CD8 T cells and CD4 T cells expression simultaneously because they have crucial networks in tumour targeting immune responses. In 97 RCC ...patients, RNA sequencing and gene set enrichment analysis of both CD8 and CD4 T cells based on the expression levels of PD-1 and TIM-3 implied that the populations of PD-1+TIM-3+ CD8 T cells and PD-1lowTIM-3 + CD4 T cells were characterized as exhausted CD8 T cells and regulatory CD4 T cells, respectively. These populations of CD4 and CD8 T cells were significantly upregulated in the patients with RCC of higher WHO/ISUP grade (grades 3, 4) (P < 0.001). Moreover, the cytokine productivities of each population in both CD4 and CD8 T cells of the higher-grade patients were significantly lower than those of the lower-grade patients (P < 0.05). Multivariate analysis showed the prognosis of patients with metastatic RCC of higher WHO/ISUP grade treated by nivolumab to be significantly worse than that of patients with lower grade (P = 0.026). This study showed that tumour grade significantly correlated with dysfunction of both CD4+ and CD8+ TILs and the efficacy of nivolumab treatment.
Monopolar spindle 1 (Mps1) is an attractive oncology target due to its high expression level in cancer cells as well as the correlation of its expression levels with histological grades of cancers. ...An imidazo1,2-apyrazine 10a was identified during an HTS campaign. Although 10a exhibited good biochemical activity, its moderate cellular as well as antiproliferative activities needed to be improved. The cocrystal structure of an analogue of 10a guided our lead optimization to introduce substituents at the 6-position of the scaffold, giving the 6-aryl substituted 21b which had improved cellular activity but no oral bioavailability in rat. Property-based optimization at the 6-position and a scaffold change led to the discovery of the imidazo1,2-bpyridazine-based 27f, an extremely potent (cellular Mps1 IC50 = 0.70 nM, A549 IC50 = 6.0 nM), selective Mps1 inhibitor over 192 kinases, which could be orally administered and was active in vivo. This 27f demonstrated remarkable antiproliferative activity in the nanomolar range against various tissue cancer cell lines.
Immune checkpoint inhibitors (ICIs) exert beneficial effects in non-small cell lung cancer (NSCLC) patients. However, ICIs are only advantageous for a limited population of NSCLC patients. Therefore ...to enhance their effects, combination therapies with ICIs have been developed. To identify preferable chemotherapy to combine with ICIs against lung cancer, we examined immunological effects of docetaxel compared with epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI). We found no difference in peripheral lymphocyte counts and ratio of their subpopulations in lung cancer patients before and after both treatments. On the other hand, plasma levels of high-mobility group box 1 (HMGB1), a damage-associated molecular pattern (DAMP) protein, showed significant increase after docetaxel treatment. Furthermore, we investigated effects of HMGB1 on tumor-infiltrating immune cells obtained from surgically resected tumor tissue from NSCLC patients. When the tumor infiltrating cells were stimulated with HMGB1, CD11c+ cells showed increased expression of activation markers. These findings imply that docetaxel could be involved in anti-tumor immunity via HMGB1. Therefore docetaxel might be a candidate for combination treatment with ICIs.
CD4+CD8+ T cells are a prognostic marker for renal cell carcinoma
Abstract
Objective
CD4+CD8+ T cells are expressed in some cancer patients including those with renal cell carcinoma (RCC). However, ...no reports have mentioned the clinical importance of this expression. We evaluated the expression of CD4+CD8+ T cells in patients with various cancer types to clarify clinical characteristics and prognostic importance significantly correlating with these T cells.
Methods
Expression of CD4+CD8+ T cells was evaluated using flowcytometry in tissue-infiltrating lymphocytes extracted from 260 cancer tissues including 104 RCC samples. RNA sequencing and characterization and regression (Citrus) was used to determine characteristics. The prognostic importance of CD4+CD8+ T cells was evaluated by Cox regression analysis.
Results
Among eight cancer types, expression of CD4+CD8+ T cells was significantly highest in RCC patients. According to the expression of CD4+CD8+ T cells in adjacent normal tissue-infiltrating lymphocytes, 24 patients (23.1%) were defined as being positive for CD4+CD8+ with an expression higher than 9.29% in RCC patients. Citrus showed CD8+PD-1+TIM-3+CD103− T cells to be a specific subpopulation of CD4+CD8+ T cells. RNA sequencing revealed that CD4+CD8+ T cells had significantly lower diversity than the other T cells and shared most T-cell receptor clones with CD8+ not CD4+ T cells. Expression of CD4+CD8+ T cells was identified as an independent predictor of overall survival (hazard ratio: 0.11, 95% confidence interval: 0.01–0.86, P = 0.035) in multivariate analysis.
Conclusions
The expression of CD4+CD8+ T cells was significantly up-regulated in RCC patients and correlated significantly with prognostic importance in surgically treated RCC patients.
Monopolar spindle 1 (Mps1) is essential for centrosome duplication, the spindle assembly check point, and the maintenance of chromosomal instability. Mps1 is highly expressed in cancer cells, and its ...expression levels correlate with the histological grades of cancers. Thus, selective Mps1 inhibitors offer an attractive opportunity for the development of novel cancer therapies. To design novel Mps1 inhibitors, we utilized the pan-kinase inhibitor anthrapyrazolone (4, SP600125) and its crystal structure bound to JNK1. Our design efforts led to the identification of indazole-based lead 6 with an Mps1 IC50 value of 498 nM. Optimization of the 3- and 6-positions on the indazole core of 6 resulted in 23c with improved Mps1 activity (IC50 = 3.06 nM). Finally, application of structure-based design using the X-ray structure of 23d bound to Mps1 culminated in the discovery of 32a and 32b with improved potency for cellular Mps1 and A549 lung cancer cells. Moreover, 32a and 32b exhibited reasonable selectivities over 120 and 166 kinases, respectively.
The C. elegans eat-3 gene encodes a mitochondrial dynamin family member homologous to Opa1 in humans and Mgm1 in yeast. We find that mutations in the C. elegans eat-3 locus cause mitochondria to ...fragment in agreement with the mutant phenotypes observed in yeast and mammalian cells. Electron microscopy shows that the matrices of fragmented mitochondria in eat-3 mutants are divided by inner membrane septae, suggestive of a specific defect in fusion of the mitochondrial inner membrane. In addition, we find that C. elegans eat-3 mutant animals are smaller, grow slower, and have smaller broodsizes than C. elegans mutants with defects in other mitochondrial fission and fusion proteins. Although mammalian Opa1 is antiapoptotic, mutations in the canonical C. elegans cell death genes ced-3 and ced-4 do not suppress the slow growth and small broodsize phenotypes of eat-3 mutants. Instead, the phenotypes of eat-3 mutants are consistent with defects in oxidative phosphorylation. Moreover, eat-3 mutants are hypersensitive to paraquat, which promotes damage by free radicals, and they are sensitive to loss of the mitochondrial superoxide dismutase sod-2. We conclude that free radicals contribute to the pathology of C. elegans eat-3 mutants.
There are no previous reports directly evaluating immunologic conditions in tumor microenvironment including both bladder cancer (BCa) and upper urinary tract carcinoma (UTUC). In this study, we ...aimed to clarify the difference of immunity status and its clinical significance depending on the tumor site in urothelial carcinoma.
Tumor tissue–infiltrating lymphocytes were extracted from 70 urothelial cancer patients who underwent surgical resection (52 cases of BCa and 18 cases of UTUC). The immunologic classification was established by unsupervised clustering analysis according to the expression ratio of 9 extracellular surface markers measured by flow cytometry, and we examined the relationship between immunologic classification and clinical importance such as pathologic status and prognosis (progression-free survival and cancer-specific survival).
The immunologic condition was classified into 2 groups. Group 1 (n = 41) comprised the CD4 T-cell–dominant group and group 2 (n = 29) the immunologically activated group. This immunologic classification was significantly correlated with tumor grade (P = .020) but not tumor location in multivariate analysis. In invasive BCa patients (n = 33), progression-free survival and cancer-specific survival of group 2 were significantly worse than those of group 1 (P = .021 and P = .022, respectively), while there was no significant difference between groups 1 and 2 in patients with invasive UTUC (n = 17).
Although there was no difference in the local immunologic condition of urothelial carcinoma between BCa and UTUC, its significance as a prognostic predictor might vary depending on tumor site.
To clarify the difference of immunity status and its clinical significance depending on the tumor site in urothelial carcinoma, we extracted 70 tumor tissue–infiltrating lymphocytes and analyzed them according to expression of surface molecules. Although there was no significant difference depending on tumor location, the results may have significance for prognosis. We should consider primary site when immunotherapy is considered for urothelial carcinoma.
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