Autophagic Markers in Chordomas: Immunohistochemical Analysis and Comparison with the Immune Microenvironment of Chordoma Tissues

Immune microenvironment and immunotherapy for chordoma

Chordoma, as a rare, low-grade malignant tumor that tends to occur in the midline of the body, grows slowly but often severely invades surrounding tissues and bones. Due to the severe invasion and damage to the surrounding tissues, chordoma is difficult to be gross totally resected in surgery, and the progression of the residual tumor is often unavoidable. Besides, the tumor is insensitive to conventional radiotherapy and chemotherapy, thus finding effective treatment methods for chordoma is urgent. Nowadays, immunotherapy has made a series of breakthroughs and shown good therapeutic effects in kinds of tumors, which brings new insights into tumors without effective treatment strategies. With the deepening of research on immunotherapy, some studies focused on the immune microenvironment of chordoma have been published, most of them concentrated on the infiltration of immune cells, the expression of tumor-specific antigen or the immune checkpoint expression. On this basis, a series of immunotherapy studies of chordoma are under way, some of which have shown encouraging results. In this review, we reviewed the research about immune microenvironment and immunotherapy for chordoma, combined with the existing clinical trials data, hoping to clarify the frontiers and limitations of chordoma immune research, and provide reference for follow-up immunotherapy research on chordoma.

The Presence of the Autophagic Markers LC3B and Sequestosome 1/p62 in the Hydatidiform Mole

Autophagy is implicated in normal pregnancy and various pathologic pregnancy conditions. Its presence in hydatidiform moles (HM) is unknown. We immunohistochemically studied 36 HM for LC3B and p62 to precisely determine their expression in the decidua, endometrium, and villi. Nineteen nonmolar pregnancies were also studied. LC3B was found in almost half of the villi and p62 was found in almost all villi. LC3B expression was significantly higher in complete HM than in partial HM. LC3B showed different expression patterns in trophoblast layers. LC3B and p62 expression was higher in molar than nonmolar pregnancies. Autophagic markers are present in HM and their expression differs between complete and partial moles.

Chordoma recruits and polarizes tumor-associated macrophages via secreting CCL5 to promote malignant progression

BACKGROUND

Chordoma is an extremely rare, locally aggressive malignant bone tumor originating from undifferentiated embryonic remnants. There are no effective therapeutic strategies for chordoma. Herein, we aimed to explore cellular interactions within the chordoma immune microenvironment and provide new therapeutic targets.

METHODS

Spectrum flow cytometry and multiplex immunofluorescence (IF) staining were used to investigate the immune microenvironment of chordoma. Cell Counting Kit-8, Edu, clone formation, Transwell, and healing assays were used to validate tumor functions. Flow cytometry and Transwell assays were used to analyze macrophage phenotype and chemotaxis alterations. Immunohistochemistry, IF, western blot, PCR, and ELISA assays were used to analyze molecular expression. An organoid model and a xenograft mouse model were constructed to investigate the efficacy of maraviroc (MVC).

RESULTS

The chordoma immune microenvironment landscape was characterized, and we observed that chordoma exhibits a typical immune exclusion phenotype. However, macrophages infiltrating the tumor zone were also noted. Through functional assays, we demonstrated that chordoma-secreted CCL5 significantly promoted malignancy progression, macrophage recruitment, and M2 polarization. In turn, M2 macrophages markedly enhanced the proliferation, invasion, and migration viability of chordoma. CCL5 knockdown and MVC (CCL5/CCR5 inhibitor) treatment both significantly inhibited chordoma malignant progression and M2 macrophage polarization. We established chordoma patient-derived organoids, wherein MVC exhibited antitumor effects, especially in patient 4, with robust killing effect. MVC inhibits chordoma growth and lung metastasis in vivo.

CONCLUSIONS

Our study implicates that the CCL5-CCR5 axis plays an important role in the malignant progression of chordoma and the regulation of macrophages, and that the CCL5-CCR5 axis is a potential therapeutic target in chordoma.

Loss of SMARCB1 promotes autophagy and facilitates tumour progression in chordoma by transcriptionally activating ATG5

OBJECTIVES

SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1 (SMARCB1) loss is associated with a poor prognosis in chordoma, while the mechanism remains largely unclear. Here, we aim to explore the function and regulatory mechanisms of SMARCB1 in chordoma.

MATERIALS AND METHODS

The effect of SMARCB1 on chordoma cells was investigated in vitro and in vivo. Chromatin immunoprecipitation (ChIP) sequencing was used to investigate the mechanisms of SMARCB1 in chordoma. The association between SMARCB1 and autophagy was validated by Western blot, immunofluorescence and transmission electron microscopy. In addition, the ATG5 expression in chordoma tissue was assessed using immunohistochemistry and correlated with patient survival.

RESULTS

SMARCB1 inhibited the malignant phenotype of chordoma cells in vitro and in vivo, supporting a tumour suppressor role of SMARCB1 in chordoma. ATG5-mediated autophagy was identified as a potential downstream pathway of SMARCB1. Mechanistically, SMARCB1 bound directly to the ATG5 promoter and epigenetically inhibited its transcription, which decreased ATG5 expression and impaired autophagy. Additionally, autophagy inhibitor chloroquine had a potential anti-cancer effect on chordoma cells in vitro. Moreover, high ATG5 expression was observed in recurrent chordoma patients, which independently correlated with adverse outcomes.

CONCLUSIONS

Taken together, our results revealed that the SMARCB1/ATG5 axis is a promising therapeutic target for chordoma and autophagy inhibitors may be effective agents for chordoma treatment.

Primary central nervous system lymphomas express immunohistochemical factors of autophagy

Primary central nervous system lymphoma (PCNSL) is an aggressive and rare disease. Autophagy is a catabolic mechanism boosting various tumors, including lymphomas; its inhibition is thus a promising therapeutic target. Its presence has never been studied in PCNSLs. We conducted a retrospective immunohistochemical study of 25 PCNSLs for LC3B, p62, and M6PR, comparing it with clinicopathological characteristics. Fourteen (56%) and eleven (44%) PCNSLs were of low and high LC3B expression, respectively. p62 expression was present in most tumors (n = 21, 84%). M6PR was present in all tumors, with 14 (56%) and 11 (44%) cases being of low and high M6PR expression, respectively. LC3B expression was correlated with the performance status (PS) (p = 0.04). No association was found with other clinical parameters, such as deep structure invasion, multiple lesions, complete response, and recurrence after response. p62 showed a strong positive association with MUM1 expression (p = 0.0005). M6PR expression showed a positive correlation (p = 0.04) with PD-L1 expression. No association was found with p53, Ki67, CD8, BCL2, BCL6, or double MYC/BLC2 co-expressors. No association of LC3B, p62, and M6PR expression with survival was found. Our findings provide evidence for the possible presence of autophagic markers in PCNSLs and, thus, for possible treatment targets.

PD-L1 Status in Gastric Cancers, Association with the Transcriptional, Growth Factors, AKT/mTOR Components Change, and Autophagy Initiation

Introduction: The programmed death receptor ligand 1 (PD-L1) immunohistochemistry (IHC) assay is a widely used selection method for pembrolizumab treatment in gastric cancer (GC) patients. PD-L1 is the main regulator of immunity in oncogenesis. Material and methods: The study included 38 patients with GC. The combined treatment consisted of neoadjuvant FOLFOX6, or FLOT, chemotherapy and surgery. PD-L1 + tumor status was recorded in 12 patients (CPS > 5), with a negative status recorded in 26 patients. RT-PCR determined the expression of molecular markers. The level of LC3B protein was detected by Western Blotting analysis. Results: An overexpression of PD-1, PD-L2 in the tumor is associated with AKT/mTOR mRNA profile change and autophagy initiation in IHC PD-L1 positive GCs. NACT influences these biological features, modifying the expression of AKT/mTOR components and autophagic flux. In PD-L1 positive cancers, the effect of NACT and molecular markers rearrangements are essential compared to the PD-L1 negative cancers. Conclusion: The IHC PD-L1 status in gastric cancers is the significant marker of cancer progression, recovering the multiple inner mechanisms of cancer spreading and leading to ineffective therapy. Autophagy induction and angiogenesis are found in PD-L1 positive gastric cancers.

Autophagy and immune microenvironment in craniopharyngioma and ameloblastoma

BACKGROUND

Craniopharyngiomas and ameloblastomas show remarkable histologic and molecular similarities. The immune microenvironment of craniopharyngiomas has been recently studied showing interesting findings, while its composition in ameloblastomas is unknown. Similarly, some evidence of autophagic activity, a process of cellular constituents' degradation has been found in ameloblastomas, but no studies exist in craniopharyngiomas. Thus, the aim of the study is to compare factors of the immune microenvironment and the autophagic apparatus between these two tumor types.

METHODS

26 craniopharyngiomas and 14 ameloblastomas were immunohistochemically studied for PD-L1, CD8, CD20, S100, CD163, MECA-79, LC3B and p62.

RESULTS

Craniopharyngiomas showed higher LC3B tumor cell expression, higher CD8+ T cells and higher CD163+ macrophages in comparison to ameloblastomas. LC3B tumor cell expression was associated with overall survival in craniopharyngioma patients and p62 nuclear expression was associated with overall survival in ameloblastoma patients.

CONCLUSION

This is the first study showing the presence of autophagic markers in craniopharyngiomas and describing the immune microenvironment of ameloblastomas.

Autophagy in cardiac myxoma: An important puzzle piece in understanding its inflammatory environment

BACKGROUND

Cardiac myxomas are rare, predominantly sporadic tumors that can cause heart failure and systematic inflammatory symptoms, and increase the risk of emboli. Their pathophysiology remains poorly understood, but intra-tumoral inflammation and senescence seem to be implicated in it. One of the principal cellular mechanisms implicated in tumor progression is autophagy, largely unknown in myxomas. Thus, our study aimed to investigate the presence of autophagic markers in myxomas and to correlate it with their immune microenvironment.

METHODS

Twenty-five cardiac myxomas were studied for the autophagic markers LC3B and p62/sequestosome 1 and were compared with markers of the immune microenvironment.

RESULTS

Most myxomas showed expression of both autophagic markers. We found a positive correlation between LC3B and PD-L1, as well as CD163, and a negative correlation between LC3B and CD8, CD20, CD138, and CD117 infiltration.

CONCLUSION

Our data not only confirm the presence of autophagic markers within cardiac myxomas but also suggest a possible association with their immune microenvironment.