Integrative analysis identifies activated anti-tumor immune microenvironment in lung metastasis of pancreatic cancer

Pulmonary metastases from pancreatic cancer have different clinico-radiological features compared with those from colorectal cancer

BACKGROUND

Although pulmonary metastasectomy is a commonly-performed procedure, data are lacking on the feasibility and oncological efficacy of removal of pulmonary metastases from pancreatic cancer. In this study, we retrospectively compared features of pulmonary metastases from pancreatic cancer versus colorectal cancer (CRC, patients with CRC being common candidates for pulmonary metastasectomy) and outcomes of removing such metastases, with our aim being to identify specific features of the former.

METHODS

Data on removal of 182 pulmonary metastases (29 from pancreatic and 153 from CRC) performed from January 2013 to April 2024 were included in this analysis. Radio-pathological findings were compared between these groups. The study cohort comprised 139 pulmonary metastasectomies in 119 patients (24 with pancreatic cancer and 95 with CRC) in whom R0 resection was achieved and follow-up data were available.

RESULTS

Atypical radiological findings of pulmonary metastases, including polygonal-shape (P < 0.001), spiculae (P < 0.001), air bronchogram (P = 0.012), peripheral ground-glass opacities (P < 0.001), and pleural tags (P < 0.001) were present more frequently in metastases from pancreatic cancer than from CRC. Furthermore, pleural lavage cytology was more frequently positive in pulmonary metastases from pancreatic cancer than in those from CRC (P < 0.001). Disease-free survival was significantly shorter after the removal of metastases from pancreatic than from CRC (P < 0.001).

CONCLUSIONS

Some pulmonary metastases from pancreatic cancer have atypical radiological features. Surgical interventions for these may enable diagnosis. The prognosis is significantly poorer after removing metastases from pancreatic cancer than from CRC. The therapeutic significance of our findings requires further investigation.

Isolated lung metastases from pancreatic ductal adenocarcinoma (PDAC): Diagnostic and therapeutic challenges of a different disease

Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis, mostly due to the high rate of distant dissemination. However, growing evidence shows that isolated lung recurrence or metastases (ILM) from PDAC are not only less common, but also correlated with a better prognosis. Lung-only recurrence after surgery occurs later in time and is associated with more favorable prognostic characteristics of the primary tumor. Moreover, recent findings suggest that this specific site of metastases is characterized by an immunologically "hot" microenvironment and a more favorable molecular profile that could possibly justify its clinical behavior. Thus, ILM from PDAC emerge as a distinct entity, that might also benefit from a different therapeutic approach, possibly with the integration of surgery and de-intensified chemotherapy regimens, especially in selected patients. In this review we delve into the current scientific evidence on the clinical and biological characteristics of isolated LM from PDAC, also focusing on concerns with their diagnostic process and the therapeutic options for the management of this subset of patients.

Clinical benefits of pulmonary resection for lung metastases from pancreatic cancer

PURPOSE

Systemic chemotherapy is generally used for metastatic pancreatic cancer; however, pulmonary resection may be a treatment option for lung oligometastases from pancreatic cancer. The current study aimed to clarify the oncological outcomes and clinical benefits of pulmonary resection for lung metastases.

METHODS

Of 510 patients who underwent pancreatic resection for pancreatic cancer, 44 patients with recurrence of isolated lung metastases and one patient with simultaneous lung metastases were evaluated.

RESULTS

Of the 45 patients, 20 patients were selected as candidates for pulmonary resection based on clinical factors such as recurrence-free interval (RFI) from pancreatectomy to lung metastases, number of lung metastases, and serum CA19-9 level. The post-recurrent survival of patients with pulmonary resection was significantly better than that of patients without pulmonary resection. Fourteen of the 20 patients with pulmonary resection developed tumor recurrence with a median disease-free survival (DFS) of 15 months. Univariate analyses revealed that an RFI from pancreatectomy to lung metastases of ≥28 months was associated with better DFS after pulmonary resection. Of the 14 patients with an RFI of ≥28 months, pulmonary resection resulted in prolonged chemotherapy-free interval in 12 patients. Furthermore, repeat pulmonary resection for recurrent tumors after pulmonary resection led to further cancer-free interval in some cases.

CONCLUSIONS

Although many patients had tumor recurrence after pulmonary resection, pulmonary resection for lung metastases from pancreatic cancer may provide prolonged cancer-free interval without the need for chemotherapy. Pulmonary resection should be performed for the patients with a long RFI from pancreatectomy to lung metastases.

Identification of Nectin Family Interactive Gene Panel and Stratification of Clinical Outcomes in Patients with Pancreatic Cancer

BACKGROUND

Although patient-risk stratification is important for selecting individualized treatment for pancreatic ductal adenocarcinoma (PDAC), predicting the oncologic outcomes after surgery remains a challenge. In this study, we identified a nectin family gene panel (NFGP) that can accurately stratify oncologic outcomes in patients with PDAC.

STUDY DESIGN

Comprehensive analysis of the expression of 9 nectin family genes identified the NFGP, which was assessed for predictive performance in 2 independent public cohorts (The Cancer Genome Atlas [TCGA] n = 176; International Cancer Genome Consortium [ICGC] n = 89). It was subsequently trained and validated for the in-house training cohort without neo-adjuvant therapy (NAT, n = 213) and the validation cohort with NAT (n = 307).

RESULTS

Using the Cox regression model, NFGP derived from 9 nectin family genes accurately stratified overall survival (OS) in TCGA (p = 0.038) and ICGC (p = 0.005). We subsequently optimized NFGP, which robustly discriminated postoperative prognosis, OS (p = 0.014) and relapse-free survival ([RFS] p = 0.006) in the training cohort. The NFGP was successfully validated in an independent validation cohort (OS: p < 0.001; RFS: p = 0.004). Multivariate analysis demonstrated the NFGP was an independent prognostic factor for OS and RFS in the training (p = 0.028 and 0.008, respectively) and validation (p < 0.001 and 0.013, respectively) cohorts. The subcohort analyses showed that the predictive performance of NFGP is applicable to the patients' subcohort according to resectability or adjuvant therapy status. Additionally, a combination model of NFGP score and CA19-9 level emerged with improved accuracy for predicting prognosis.

CONCLUSIONS

This study established the predictive significance of NFGP for oncologic outcomes after surgery in PDAC. Our data demonstrate its clinical impact as a potent biomarker for optimal patient selection for individualized treatment strategies.

Interpretations of the Role of Plasma Albumin in Prognostic Indices: A Literature Review

This review assesses how publications interpret factors that influence the serum or plasma albumin (PA) level in prognostic indices, focusing on inflammation and nutrition. On PubMed, a search for "albumin AND prognosis" yielded 23,919 results. From these records, prognostic indices were retrieved, and their names were used as search strings on PubMed. Indices found in 10 or more original research articles were included. The same search strings, restricted to "Review" or "Systematic review", retrieved yielded on the indices. The data comprised the 10 latest original research articles and up to 10 of the latest reviews. Thirty indices had 294 original research articles (6 covering two indices) and 131 reviews, most of which were from recent years. A total of 106 articles related the PA level to inflammation, and 136 related the PA level to nutrition. For the reviews, the equivalent numbers were 54 and 65. In conclusion, more publications mention the PA level as a marker of nutrition rather than inflammation. This is in contrast to several general reviews on albumin and nutritional guidelines, which state that the PA level is a marker of inflammation but not nutrition. Hypoalbuminemia should prompt clinicians to focus on the inflammatory aspects in their patients.

NLRP3 inflammasome-induced pyroptosis in digestive system tumors

Programmed cell death (PCD) refers to cell death in a manner that depends on specific genes encoding signals or activities. PCD includes apoptosis, pyroptosis, autophagy and necrosis (programmed necrosis). Among these mechanisms, pyroptosis is mediated by the gasdermin family and is accompanied by inflammatory and immune responses. When pathogens or other danger signals are detected, cytokine action and inflammasomes (cytoplasmic multiprotein complexes) lead to pyroptosis. The relationship between pyroptosis and cancer is complex and the effect of pyroptosis on cancer varies in different tissue and genetic backgrounds. On the one hand, pyroptosis can inhibit tumorigenesis and progression; on the other hand, pyroptosis, as a pro-inflammatory death, can promote tumor growth by creating a microenvironment suitable for tumor cell growth. Indeed, the NLRP3 inflammasome is known to mediate pyroptosis in digestive system tumors, such as gastric cancer, pancreatic ductal adenocarcinoma, gallbladder cancer, oral squamous cell carcinoma, esophageal squamous cell carcinoma, in which a pyroptosis-induced cellular inflammatory response inhibits tumor development. The same process occurs in hepatocellular carcinoma and some colorectal cancers. The current review summarizes mechanisms and pathways of pyroptosis, outlining the involvement of NLRP3 inflammasome-mediated pyroptosis in digestive system tumors.

Essential updates 2021/2022: Surgical outcomes of oligometastasis in pancreatic ductal adenocarcinoma

Oligometastatic disease has been proposed as an intermediate state between localized and polymetastatic disease that can benefit from multimodal treatment, including surgery. There is a growing concern about performing surgery for oligometastatic pancreatic ductal adenocarcinoma, although there is still little evidence. We reviewed articles published between 2021 and 2022, focusing mainly on surgical outcomes. Furthermore, we summarized the current status of surgery in the multidisciplinary treatment of oligometastatic pancreatic cancer and discuss future perspectives. In liver oligometastasis, multimodal treatment including surgery achieved favorable long-term survival, especially in patients with good responses to preoperative chemotherapy, with a median survival time from 25.5 to 54.6 months. In addition, the data from the National Cancer Database in the United States showed that patients who underwent surgery for oligometastatic liver metastases had a significantly longer overall survival than those who received chemotherapy alone. Prognostic biomarkers were identified, including carbohydrate antigen 19-9 (CA19-9) levels at diagnosis and preoperative chemotherapy with normalization of CA19-9 levels or favorable radiological response. Patients with lung oligometastasis had a more favorable long-term prognosis than those with other recurrence sites, and the updated literature further confirmed the previous studies. Overall survival was favorable, with 84 months after initial surgery and 29.2 months after metastasectomy, and a 5-year survival rate of 60.6% was also reported. In peritoneal oligometastasis, the results of conversion surgery after good responses to preoperative treatment with intraperitoneal therapy or systematic chemotherapy were reported, and the conversion rate and long-term prognosis were favorable. There is a growing concern about performing surgery for oligometastatic pancreatic ductal adenocarcinoma. We reviewed articles published between 2021 and 2022, focusing mainly on surgical outcomes. Furthermore, we summarize the current status of surgery in multidisciplinary treatment of oligometastatic pancreatic cancer and discuss future perspectives.

Integrated analysis of lncRNAs and mRNAs by RNA-Seq in secondary hair follicle development and cycling (anagen, catagen and telogen) of Jiangnan cashmere goat (Capra hircus)

BACKGROUND

Among the world's finest natural fiber composites is derived from the secondary hair follicles (SHFs) of cashmere goats yield one of the world's best natural fibres. Their development and cycling are characterized by photoperiodism with diverse, well-orchestrated stimulatory and inhibitory signals. Long non-coding RNA (lncRNAs) and mRNAs play important roles in hair follicle (HF) development. However, not many studies have explored their specific functions in cashmere development and cycling. This study detected mRNAs and lncRNAs with their candidate genes and related pathways in SHF development and cycling of cashmere goat. We utilized RNA sequencing (RNA-Seq) and bioinformatics analysis on lncRNA and mRNA expressions in goat hair follicles to discover candidate genes and metabolic pathways that could affect development and cycling (anagen, catagen, and telogen).

RESULTS

We identified 228 differentially expressed (DE) mRNAs and 256 DE lncRNA. For mRNAs, catagen and anagen had 16 upregulated and 35 downregulated DEGs, catagen and telogen had 18 upregulated and 9 downregulated DEGs and telogen and anagen had 52 upregulated and 98 downregulated DEGs. LncRNA witnessed 22 upregulated and 39 downregulated DEGs for catagen and anagen, 36 upregulated and 29 downregulated DEGs for catagen and telogen as well as 66 upregulated and 97 downregulated DEGs for telogen and anagen. Several key genes, including MSTRG.5451.2, MSTRG.45465.3, MSTRG.11609.2, CHST1, SH3BP4, CDKN1A, GAREM1, GSK-3β, DEFB103A KRTAP9-2, YAP1, S100A7A, FA2H, LOC102190037, LOC102179090, LOC102173866, KRT2, KRT39, FAM167A, FAT4 and EGFL6 were shown to be potentially important in hair follicle development and cycling. They were related to, WNT/β-catenin, mTORC1, ERK/MAPK, Hedgehog, TGFβ, NFkB/p38MAPK, caspase-1, and interleukin (IL)-1a signaling pathways.

CONCLUSION

This work adds to existing understanding of the regulation of HF development and cycling in cashmere goats via lncRNAs and mRNAs. It also serves as theoretical foundation for future SHF research in cashmere goats.

NLRP3 activation in tumor-associated macrophages enhances lung metastasis of pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer and is highly malignant due to its late diagnosis and early metastasis. Lung metastasis of PDAC occurs in a significant number of diagnosed patients and represents high severity of disease and poor clinical outcome. However, the molecular regulation of lung metastasis of PDAC is still not fully understood. Tumor-associated macrophages (TAMs) have recently been found to play an important role in cancer initiation, proliferation, progression, and metastasis. The proliferation, differentiation, and polarization of macrophages has been shown to be regulated by interleukin 1β (IL-1β), which is generated by NLR family pyrin domain containing 3 (NLRP3)-induced formation of inflammasome. Herein we investigated whether NLRP3 plays a role in lung metastasis of PDAC through regulation of macrophage polarization.

METHODS

Gene profiles for NLRP3 (+/+) and NLRP3 (-/-) macrophages obtained from the Gene Expression Omnibus (GEO) public database were compared and analyzed for altered genes related to macrophage polarization. The regulation of macrophage polarization by NLRP3 was examined in a coculture system with naïve NLRP3 (+/+) or NLRP3 (-/-) macrophages and PDAC cells. Cell growth was analyzed by a Cell Counting Kit-8 (CCK-8) assay. Cell invasiveness and migratory potential were analyzed by transwell cell invasion assay and cell migration assay, respectively. PDAC formation and lung metastasis were analyzed in a mouse model of PDAC with and without NLRP3 knockout.

RESULTS

GEO database analysis revealed significant alteration in genes that regulate macrophage polarization in NLRP3-depleted macrophages. NLRP3-depletion in macrophages seemed to favor an M1/M2b polarization. In vitro, the presence of NLRP3 in macrophages led to M2a/c/d TAM-like polarization when they were cocultured with PDAC cells. Conversely, NLRP3 depletion in macrophages led to M1/M2b polarization when they were cocultured with PDAC cells. NLRP3-depletion significantly inhibited tumor growth and stage progression in a mouse model of PDAC and significantly reduced the occurrence of lung metastasis.

CONCLUSIONS

Our results suggested that NLRP3 activation in TAM enhanced lung metastasis of PDAC through regulation of TAM polarization.