Publications by authors named "Pan Juncheng"

6 Publications

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Cancer cell-autonomous overactivation of PARP1 compromises immunosurveillance in non-small cell lung cancer.

J Immunother Cancer 2022 06;10(6)

Equipe 11 labellisée par la Ligue contre le Cancer, Université de Paris Cité, Sorbonne Université, Centre de Recherche des Cordeliers, INSERM UMR1138, Paris, France

Background: High activity of poly(ADP-ribose) polymerase-1 (PARP1) in non-small cell lung cancer (NSCLC) cells leads to an increase in immunohistochemically detectable PAR, correlating with poor prognosis in patients with NSCLC, as well as reduced tumor infiltration by cytotoxic T lymphocytes (CTLs). Intrigued by this observation, we decided to determine whether PARP1 activity in NSCLC cells may cause an alteration of anticancer immunosurveillance.

Methods: Continuous culture of mouse NSCLC cells in the presence of cisplatin led to the generation of cisplatin-resistant PAR clones. As compared with their parental controls, such PAR cells formed tumors that were less infiltrated by CTLs when they were injected into immunocompetent mice, suggesting a causative link between high PARP1 activity and compromised immunosurveillance. To confirm this cause-and-effect relationship, we used CRISPR/Cas9 technology to knock out PARP1 in two PAR NSCLC mouse cell lines (Lewis lung cancer [LLC] and tissue culture number one [TC1]), showing that the removal of PARP1 indeed restored cisplatin-induced cell death responses.

Results: PARP1 knockout (PARP1) cells became largely resistant to the PARP inhibitor niraparib, meaning that they exhibited less cell death induction, reduced DNA damage response, attenuated metabolic shifts and no induction of PD-L1 and MHC class-I molecules that may affect their immunogenicity. PAR tumors implanted in mice responded to niraparib irrespective of the presence or absence of T lymphocytes, suggesting that cancer cell-autonomous effects of niraparib dominate over its possible immunomodulatory action. While PAR NSCLC mouse cell lines proliferated similarly in immunocompetent and T cell-deficient mice, PARP1 cells were strongly affected by the presence of T cells. PARP1 LLC tumors grew more quickly in immunodeficient than in immunocompetent mice, and PARP1 TC1 cells could only form tumors in T cell-deficient mice, not in immunocompetent controls. Importantly, as compared with PAR controls, the PARP1 LLC tumors exhibited signs of T cell activation in the immune infiltrate such as higher inducible costimulator (ICOS) expression and lower PD-1 expression on CTLs.

Conclusions: These results prove at the genetic level that PARP1 activity within malignant cells modulates the tumor microenvironment.
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http://dx.doi.org/10.1136/jitc-2021-004280DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9247697PMC
June 2022

Paradoxical implication of BAX/BAK in the persistence of tetraploid cells.

Cell Death Dis 2021 11 1;12(11):1039. Epub 2021 Nov 1.

Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université de Paris, Equipe 11 Labellisée par la Ligue Contre le Cancer, F-75006, Paris, France.

Pro-apoptotic multi-domain proteins of the BCL2 family such as BAX and BAK are well known for their important role in the induction of mitochondrial outer membrane permeabilization (MOMP), which is the rate-limiting step of the intrinsic pathway of apoptosis. Human or mouse cells lacking both BAX and BAK (due to a double knockout, DKO) are notoriously resistant to MOMP and cell death induction. Here we report the surprising finding that BAX/BAK DKO cells proliferate less than control cells expressing both BAX and BAK (or either BAX or BAK) when they are driven into tetraploidy by transient exposure to the microtubule inhibitor nocodazole. Mechanistically, in contrast to their BAX/BAK-sufficient controls, tetraploid DKO cells activate a senescent program, as indicated by the overexpression of several cyclin-dependent kinase inhibitors and the activation of β-galactosidase. Moreover, DKO cells manifest alterations in ionomycin-mobilizable endoplasmic reticulum (ER) Ca stores and store-operated Ca entry that are affected by tetraploidization. DKO cells manifested reduced expression of endogenous sarcoplasmic/endoplasmic reticulum Ca ATPase 2a (Serca2a) and transfection-enforced reintroduction of Serca2a, or reintroduction of an ER-targeted variant of BAK into DKO cells reestablished the same pattern of Ca fluxes as observed in BAX/BAK-sufficient control cells. Serca2a reexpression and ER-targeted BAK also abolished the tetraploidy-induced senescence of DKO cells, placing ER Ca fluxes downstream of the regulation of senescence by BAX/BAK. In conclusion, it appears that BAX/BAK prevent the induction of a tetraploidization-associated senescence program. Speculatively, this may contribute to the low incidence of cancers in BAX/BAK DKO mice and explain why human cancers rarely lose the expression of both BAX and BAK.
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http://dx.doi.org/10.1038/s41419-021-04321-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8560871PMC
November 2021

Pyridoxal kinase and poly(ADP-ribose) affect the immune microenvironment of locally advanced cancers.

Oncoimmunology 2021 8;10(1):1950954. Epub 2021 Jul 8.

Equipe 11 labellisée par la Ligue contre le Cancer, Université de Paris, Sorbonne Université, INSERM U1138, Centre de Recherche des Cordeliers, Paris, France.

Malignant cells adapt to the hostile tumor microenvironment by escaping from, or actively suppressing, anticancer immune responses. In the past, we reported that reduced synthesis of active vitamin B6 (due to downregulation of pyridoxal kinase) or overactivation of poly(ADP-ribose) polymerase confers resistance to chemotherapy with cisplatin. Recently, we found that these prognostically adverse alterations in oncometabolism also correlate with the rarefaction of immune effectors in the tumor bed.
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http://dx.doi.org/10.1080/2162402X.2021.1950954DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8274443PMC
August 2021

Metabolic features of cancer cells impact immunosurveillance.

J Immunother Cancer 2021 06;9(6)

Equipe 11 labellisée par la Ligue contre le Cancer, Université de Paris, Sorbonne Université, INSERM U1138, Centre de Recherche des Cordeliers, INSERM, Paris, France

Background: Tumors rewire their metabolism to achieve robust anabolism and resistance against therapeutic interventions like cisplatin treatment. For example, a prolonged exposure to cisplatin causes downregulation of pyridoxal kinase (PDXK), the enzyme that generates the active vitamin B6, and upregulation of poly ADP-ribose (PAR) polymerase-1 (PARP1) activity that requires a supply of nicotinamide (vitamin B3) adenine dinucleotide. We investigated the impact of the levels of PDXK and PAR on the local immunosurveillance (ie, density of the antigen presenting cells and adaptive immune response by CD8 T lymphocytes) in two different tumor types.

Methods: Tumors from patients with locally advanced cervical carcinoma (LACC) and non-small cell lung cancer (NSCLC) were stained for PAR, PDXK, dendritic cell lysosomal associated membrane glycoprotein (DC-LAMP) and CD8 T cell infiltration. Their correlations and prognostic impact were assessed. Cisplatin-resistant NSCLC cell clones isolated from Lewis-lung cancer (LLC) cells were evaluated for PAR levels by immunoblot. Parental (PAR) and cisplatin-resistant (PAR) clones were subcutaneously injected into the flank of C57BL/6 mice. Tumors were harvested to evaluate their immune infiltration by flow cytometry.

Results: The infiltration of tumors by CD8 T and DC-LAMP cells was associated with a favorable overall survival in patients with LACC (p=0.006 and p=0.008, respectively) and NSCLC (p<0.001 for both CD8 T and DC-LAMP cells). We observed a positive correlation between PDXK expression and the infiltration by DC-LAMP (R=0.44, p=0.02 in LACC, R=0.14, p=0.057 in NSCLC), and a negative correlation between PAR levels and CD8 T lymphocytes (R=-0.39, p=0.034 in LACC, R=-0.18, p=0.017 in NSCLC). PARP1 is constitutively hyperactivated in cisplatin-resistant LLC cells manifesting elevated intracellular levels of poly(ADP-ribosyl)ated proteins (PAR). Tumors formed by such cancer cells injected into immunocompetent mice were scarcely infiltrated by CD8 T (p=0.028) and antigen presenting cells (p=0.086).

Conclusions: Oncometabolic features can impact local immunosurveillance, providing new functional links between cisplatin resistance and therapeutic failure.
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http://dx.doi.org/10.1136/jitc-2021-002362DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8231002PMC
June 2021

Transcriptomic changes associated with DKK4 overexpression in pancreatic cancer cells detected by RNA-Seq.

Tumour Biol 2016 Aug 15;37(8):10827-38. Epub 2016 Feb 15.

Institute of Hepatopancreatobiliary Surgery, Southwest Hospital, Third Military Medical University, Chongqing, 400038, People's Republic of China.

The promotion of tumor development by Dickkopf 4 (DKK4) is receiving increased attention. However, the association between DKK4 and pancreatic cancer remains unclear. DKK4 expression was measured in pancreatic ductal adenocarcinoma tissues using qRT-PCR and immunohistochemistry. A DKK4-overexpressing pancreatic cancer cell line was established, and the differentially expressed genes (DEGs) that were induced by DKK4 were identified using transcriptome sequencing. The association between the identified DEGs and pancreatic cancer was assessed using gene ontology (GO), pathway analysis, pathway interaction networks, differentially expressed gene interaction network analysis, and co-expression gene networks. Finally, the accuracy of the analyses was validated using serial paraffin and frozen sections of clinical samples. DKK4 is highly expressed in pancreatic cancer tissues. DEGs of overexpression DKK4 of PANC-1 are mostly upregulated. GO and pathway analysis showed that DKK4 are associated with tumor and organ development and immune inflammation. The mitogen-activated protein kinase (MAPK) signaling pathway was the main signal transduction pathway that showed significant enrichment in overexpression DKK4 of PANC-1. The results of GO, pathway analyses, and differentially expressed gene interaction network identified genes that are closely associated with tumor development, including MAPK3, PIK3R3, VAV3, JAG1, and Notch3. The immunohistochemistry and immunofluorescence results suggested that DKK4 is co-expressed with MAPK3 and VAV3 in pancreatic cancer tissues. The results presented here show for the first time that DKK4 is highly expressed in pancreatic cancer tissues. Bioinformatics analysis of a DKK4-overexpressing of PANC-1 identified several oncogenes that are closely associated with tumors, and the MAPK signaling pathway is the core signal transduction pathway. DKK4 can be co-expressed with MAPK3 and VAV3 in pancreatic ductal adenocarcinoma tissues. Thus, DKK4 may have function on the development and progression of pancreatic cancer.
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http://dx.doi.org/10.1007/s13277-015-4379-xDOI Listing
August 2016

Specific expression of the human voltage-gated proton channel Hv1 in highly metastatic breast cancer cells, promotes tumor progression and metastasis.

Biochem Biophys Res Commun 2011 Aug 29;412(2):353-9. Epub 2011 Jul 29.

The Key Laboratory of Bioactive Materials, Ministry of Education, School of Physics Science, Nankai University, Tianjin 300071, PR China.

The newly discovered human voltage-gated proton channel Hv1 is essential for proton transfer, which contains a voltage sensor domain (VSD) without a pore domain. We report here for the first time that Hv1 is specifically expressed in the highly metastatic human breast tumor tissues, but not in poorly metastatic breast cancer tissues, detected by immunohistochemistry. Meanwhile, real-time RT-PCR and immunocytochemistry showed that the expression levels of Hv1 have significant differences among breast cancer cell lines, MCF-7, MDA-MB-231, MDA-MB-468, MDA-MB-453, T-47D and SK-BR-3, in which Hv1 is expressed at a high level in highly metastatic human breast cancer cell line MDA-MB-231, but at a very low level in poorly metastatic human breast cancer cell line MCF-7. Inhibition of Hv1 expression in the highly metastatic MDA-MB-231 cells by small interfering RNA (siRNA) significantly decreases the invasion and migration of the cells. The intracellular pH of MDA-MB-231 cells down-regulated Hv1 expression by siRNA is obviously decreased compared with MDA-MB-231 with the scrambled siRNA. The expression of matrix metalloproteinase-2 and gelatinase activity in MDA-MB-231 cells suppressed Hv1 by siRNA were reduced. Our results strongly suggest that Hv1 regulates breast cancer intracellular pH and exacerbates the migratory ability of metastatic cells.
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http://dx.doi.org/10.1016/j.bbrc.2011.07.102DOI Listing
August 2011
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