Liquid biopsy in T-cell lymphoma: biomarker detection techniques and clinical application.

T-cell lymphoma is a highly invasive tumor with significant heterogeneity. Invasive tissue biopsy is the gold standard for acquiring molecular data and categorizing lymphoma patients into genetic subtypes. However, surgical intervention is unfeasible for patients who are critically ill, have unresectable tumors, or demonstrate low compliance, making tissue biopsies inaccessible to these patients. A critical need for a minimally invasive approach in T-cell lymphoma is evident, particularly in the areas of early diagnosis, prognostic monitoring, treatment response, and drug resistance. Therefore, the clinical application of liquid biopsy techniques has gained significant attention in T-cell lymphoma. Moreover, liquid biopsy requires fewer samples, exhibits good reproducibility, and enables real-time monitoring at molecular levels, thereby facilitating personalized health care. In this review, we provide a comprehensive overview of the current liquid biopsy biomarkers used for T-cell lymphoma, focusing on circulating cell-free DNA (cfDNA), circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), Epstein-Barr virus (EBV) DNA, antibodies, and cytokines. Additionally, we discuss their clinical application, detection methodologies, ongoing clinical trials, and the challenges faced in the field of liquid biopsy.

Clinicopathological Characteristics and Molecular Phenotypes of Primary Hepatic Lymphoma.

Primary hepatic lymphoma (PHL) is a rare malignant tumor, occurring in 0.016% of non-Hodgkin's lymphoma (NHL). The common histological subtype is diffuse large B-cell lymphoma (DLBCL). Due to the rarity of tumor, clinicopathological characteristics and molecular phenotypes of PHL are limited. Seven patients with PHL (primary liver DLBCL) and 13 cases of liver involvement by DLBCL diagnosed between 2014 and 2021 in our hospital were included. The genetic features were also compared between the two groups by next-generation sequencing (NGS). Differential gene expression and pathway enrichment analysis were also performed. There were some discrepancies on presenting symptoms, pathological characteristics, laboratory data, and prognosis between PHL and DLBCL-liver groups. No same mutation was found between PHL and DLBCL-liver groups by NGS. Differential gene expression analysis discovered some up- and downregulated genes in PHL compared with the DLBCL-liver group. Upregulated genes were enriched in metabolic pathways, and downregulated genes were enriched in the HTLV-1 infection pathway. PHL is a distinct entity, with unique molecular features compared to liver involvement of systemic lymphoma. Kaplan-Meier analysis showed that the prognosis of the PHL group was better than that of the DLBCL-liver group. Understanding the clinicopathological and molecular features of PHL would help to direct clinical treatment.

The genetic landscape of pancreatic head ductal adenocarcinoma in China and prognosis stratification.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is the major subtype of pancreatic cancer and head PDACs show distinct characteristics from body/tail PDACs. With limited studies based on Asian population, the mutational landscape of Asian PDAC remains unclear. METHODS: One hundred fifty-one Chinese patients with head PDAC were selected and underwent targeted 425-gene sequencing. Genomic alterations, tumor mutational burden, and microsatellite instability were analyzed and compared with a TCGA cohort. RESULTS: The genomic landscape of Chinese and Western head PDAC had identical frequently-mutated genes including KRAS, TP53, SMAD4, and CDKN2A. KRAS hotspot in both cohorts was codon 12 but Chinese PDACs containing more G12V but fewer G12R variants. Potentially pathogenic fusions, CHD2-BRAF and KANK1-MET were identified in two KRAS wild-type patients. Serum cancer antigens CA125 and CA19-9 were positively associated with SMAD4 alterations while high CEA was enriched in wild-type CDKN2A subgroup. The probability of vascular invasion was lower in patients with RNF43 alterations. The nomogram developed including histology grade, the mutation status of SMAD4, TGFBR2, and PREX2 could calculate the risk score of prognoses validated by Chinese and TCGA cohort. CONCLUSIONS: Chinese head PDAC contained more KRAS G12V mutation than Western population. The well-performed nomogram may improve post-operation care in real-world practice.

Clinicopathological and molecular genomic features of monomorphic epitheliotropic intestinal T-cell lymphoma in the Chinese population: a study of 20 cases.

BACKGROUND: Monomorphic epitheliotropic T-cell lymphoma (MEITL) is an aggressive non-Hodgkin lymphoma with a high fatality rate. This study was aimed to explore the clinicopathological and molecular genetic features of MEITL in the Chinese population. METHODS: A retrospective analysis was performed based on the clinical manifestations and pathological features of 20 Chinese MEITL. 9 cases with paired diseased-normal tissues were also analyzed for molecular information by whole-exome sequencing. RESULTS: There were 14 men and 6 women with a median age of 58.5 (28-81) years. 17(17/20) lesions were located in the jejunum or ileum; 13(13/20) cases had ulcers or perforations. Microscopically, except for 1(1/20) case of pleomorphic cells, the monomorphic, middle-sized tumor cells infiltrating into the intestinal epithelial and peripheral intestinal mucosa recess could be seen in the other 19 cases. Immunohistochemistry showed that most of the tumor cells in MEITL were positive for CD3(20/20), CD8(17/20), CD43(19/20), and CD56(15/20), but negative for CD5(20/20). The most frequently mutated genes of these Chinese cases were STAT5B (4/9) and TP53 (4/9), not SETD2(2/9). JAK3 mutations (3/9) were also detected with a high mutated frequency. We demonstrated that mutations of JAK-STAT pathway-related genes and the amplification of Chromosome 9q appeared at the same time in most cases(5/9). CONCLUSIONS: The clinicopathological features were consistent with that in previous western studies, but a special case with pleomorphic cells was found in this study. The co-occurrence of JAK-STAT pathway-related gene mutations and the amplification of Chr9q is a molecular feature of MEITL.

Genomic alterations in biliary tract cancer predict prognosis and immunotherapy outcomes.

BACKGROUND: Recently, immunotherapy with immune checkpoint inhibitors (ICIs) has shown promising efficacy in biliary tract cancer (BTC), which includes gallbladder cancer (GBC) and cholangiocarcinoma (CHOL). Understanding the association between immunotherapy outcomes and the genomic profile of advanced BTC may further improve the clinical benefits from immunotherapy. METHODS: Genomic tumor DNA was isolated from 98 Chinese patients with advanced BTC and used for targeted next-generation sequencing of 416 cancer-related genes to identify the genomic alterations common to advanced BTC. Thirty-four patients had received ICI camrelizumab plus gemcitabine and oxaliplatin (from the NCT03486678 trial) as a first-line treatment. Tumor-infiltrating immune cells were evaluated using immunofluorescence staining. RESULTS: KRAS and TP53 mutations were much more frequent in the advanced-stage BTC cohort than in other cohorts with mostly early stage disease. Specifically, KRAS-TP53 co-mutations were favored in advanced CHOL, with a favorable response to immunotherapy, while single KRAS mutations predicted poor prognosis and immunotherapy outcomes for CHOL. Compared with GBC, CHOL had more mutations in genes involved in KRAS signaling; a high mutation load in these genes correlated with poor immunotherapy outcomes and may subsequently cause inferior immunotherapy outcomes for CHOL relative to GBC. Furthermore, a genomic signature including 11 genes was developed; their mutated subtype was associated with poor prognosis and immunotherapy outcomes in both CHOL and GBC. Transcriptome analyses suggested immune dysfunction in the signature mutated subtype, which was validated by tumor microenvironment (TME) evaluation based on detection of immune cell infiltration. Importantly, the signature wild-type subtype with favorable TME may be an advantageous population of immunotherapy. CONCLUSIONS: Genomic alterations in advanced BTC were associated with specific prognosis and immunotherapy outcomes. Combining genomic classification with TME evaluation further improved the stratification of immunotherapy outcomes.

Tumor mutation burden as a biomarker in resected gastric cancer via its association with immune infiltration and hypoxia.

BACKGROUND: Tumor mutation burden (TMB) predicts immunotherapy efficacy in solid tumors. However, the biomarker role of TMB is still conflicting in resected tumors. We aimed to examine the association of TMB with prognosis and postoperative chemotherapy (CT) or radiochemotherapy (RCT) efficacy in resected gastric cancer (GC). METHODS: Whole-exome sequencing (WES) was performed in 73 resected GC specimens. Validation cohorts included 352 patients from The Cancer Genome Atlas (TCGA) and 222 patients from the Asian Cancer Research Group (ACRG). Immune infiltration and hypoxia were evaluated by transcriptome data and immunohistochemistry assay. RESULTS: TMB-high GC had favorable overall survival (OS) and disease-free survival (DFS), but the OS and DFS benefits with postoperative CT/RCT were more pronounced in TMB-low GC. These findings were consistent among all three cohorts and were maintained in the pooled cohort. Stratified by stages in the pooled cohort, stage III GC benefited from postoperative CT/RCT regardless of TMB level while stage Ib/II GC benefited from postoperative CT/RCT in TMB-low but not in TMB-high subgroup. TMB positively correlated with immune infiltration which was characterized by NK cell rather than CD8 + T cell enrichment. TMB-high GC was more hypoxic than TMB-low GC, and TMB-high stage Ib/II GC was the most hypoxic. CONCLUSIONS: High TMB may predict favorable prognosis in resected GC but poor response to postoperative CT/RCT in stage Ib/II subgroup, which may be determined by TMB-associated immune infiltration and hypoxia, respectively.

Baseline Mutations and Up-Regulation of PI3K-AKT Pathway Serve as Potential Indicators of Lack of Response to Neoadjuvant Chemotherapy in Stage II/III Breast Cancer.

Background: Neoadjuvant chemotherapy (NAC) has been expanded to hormone receptor (HR) positive breast cancer (BC) patients with operable disease, to increase the likelihood of breast-conserving surgery. Genomic profiling at baseline would reveal NAC response relevant genomic features and signaling pathways, guiding clinical NAC utilization based on patients' genomic characteristics. Methods: We prospectively studied stage II/III BC patients who were eligible for breast-conserving surgery. Patients received epirubicin and cyclophosphamide for 4 cycles, followed by another 4-cycle docetaxel, and human epidermal growth factor receptor (HER2) positive patients were additionally treated with herceptin when using docetaxel (EC-T(H)). NAC responses were evaluated as pathologic complete response (pCR) or non-pathologic complete response (non-pCR). Genomic features related to NAC responses were identified by profiling baseline tumor tissues sampled one day before NAC, using whole-exome sequencing. Differentially expressed genes and up-/down-regulated pathways were investigated by performing RNA-sequencing. Results: A total of 25 stage II/III BC patients were enrolled, including 5 patients ultimately evaluated as pCR and 20 patients evaluated as non-pCR. PIK3CA (48%) and TP53 (40%) mutations were enriched in patients not achieving pCR. Mutated phosphatidylinositol-3-kinase-AKT (PI3K-AKT) pathway and homologous recombinational repair pathway were also more frequently observed in patients evaluated as non-pCR. Significant arm-level amplifications (8q24.23 and 17q12) and deletions (1p32.2, 4p14, 7q11.23, 10q21.3, 11q23.3, etc.) were identified among patients not achieving pCR, while patients achieving pCR displayed no significant copy number alterations. Significantly up-regulated expression of PI3K-AKT pathway genes was also detected among patients failed to achieve pCR, compared to patients achieving pCR. Conclusion: Compared to BC patients achieving pCR to NAC, aberrant activation of PI3K-AKT pathway genes were more frequently observed in patients not achieving pCR, consistent with the significant up-regulation of PI3K-AKT pathway gene expression in the non-pCR subgroup. Together, these findings indicate that upregulated PI3K-AKT pathway serves as a potential indicator of lack of response to NAC in stage II/III BC patients, and other effective therapeutic options are urgently needed for those resistant patients.

FBXW7 and Its Downstream NOTCH Pathway Could be Potential Indicators of Organ-Free Metastasis in Colorectal Cancer.

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths globally. Metastasis is associated with a poor prognosis, yet the underlying molecular mechanism(s) remained largely unknown. In this study, a total of 85 CRC patients were included and the primary tumor lesions were evaluated by next-generation sequencing using a targeted panel for genetic aberrations. Patients were sub-divided according to their metastasis pattern into the non-organ metastases (Non-OM) and organ metastases (OM) groups. By comparing the genetic differences between the two groups, we found that mutations in FBXW7 and alterations in its downstream NOTCH signaling pathway were more common in the Non-OM group. Moreover, correlation analysis suggested that FBXW7 mutations were independent of other somatic alterations. The negative associations of alterations in FBXW7 and its downstream NOTCH signaling pathway with CRC organ metastasis were validated in a cohort of 230 patients in the TCGA CRC dataset. Thus, we speculated that the genomic alterations of FBXW7/NOTCH axis might be an independent negative indicator of CRC organ metastases.

Durable Complete Response to Alectinib in a Lung Adenocarcinoma Patient With Brain Metastases and Low-Abundance EML4-ALK Variant in Liquid Biopsy: A Case Report.

EML4-ALK fusions are targetable oncogenic drivers in a subset of advanced non-small cell lung cancer (NSCLC) patients that can benefit from selected ALK inhibitors. Precise detection of ALK fusions may yield critical information for selection of appropriate therapy and hence improve patient survival. Analysis of circulating tumor DNA (ctDNA) in liquid biopsies using next generation sequencing (NGS) prior to or during treatment hold great promise for disease monitoring and treatment guidance of various cancers including NSCLC. Herein, we report a case of a 21-year-old advanced lung adenocarcinoma patient with a low abundance (0.03%) of EML4-ALK rearrangement identified in plasma ctDNA upon progression on two lines of chemotherapy that demonstrated long-term complete response to alectinib (>13 months) including metastatic brain tumors. Patient's clinical and pathologic characteristics, computerized tomography (CT) scans and brain magnetic resonance imaging (MRI) were reviewed retrospectively. Taken together, our report not only reinforces the translational utility of NGS-based genomic sequencing of liquid biopsy in guiding clinical practice, but also highlights the superior efficacy of alectinib than chemotherapy in ALK+ NSCLC with brain metastases, albeit at a low variant allele abundance.

Stem-like tumor cells involved in heterogeneous vasculogenesis in breast cancer.

Sorafenib, a small-molecule tyrosine kinase inhibitor with antiangiogenic activity, has been used in liver cancer and kidney cancer treatments. However, clinical trials with sorafenib for breast cancer were stopped in phase III due to limited efficacy. The existence of heterogeneous vasculatures involving tumor cells, such as vessel-like structures formed by vasculogenic mimicry and mosaic vessels, and their resistance to antiangiogenic therapy are thought to be a possible reason for failure of sorafenib therapy. Nevertheless, the features and mechanism of vasculogenesis by tumor cells remain unclear. In the present study, we found that breast cancer stem-like cells (BCSLCs, ALDH1+ cells) were involved in vasculogenic mimicry and mosaic vessel formation in triple-negative breast cancer tissues. Further, only ALDH1+ BCSLCs sorted from MDA-MB-231 could exhibit the tube formation and angiogenesis ability. Sorafenib could inhibit vascularization from endothelial cells rather than that from ALDH1+ cells. α-SMA was identified as a key molecule in vascular formation of BCSLCs. Mechanistically, HIF-1α enhanced the mRNA and protein levels of α-SMA by binding to the HRE element in the promoter directly and meanwhile increased the BCSLCs population. Interestingly, pigment epithelium-derived factor (PEDF), an endogenous angiogenesis inhibitor, could inhibit both endothelial cell-derived and tumor cell-derived angiogenesis by downregulating HIF-1α in breast cancer. Our finding clarified the possible reason for the poor outcome of anti-angiogenesis therapy and PEDF may have the therapeutic potential.

Tumor Microenvironment Status Predicts the Efficacy of Postoperative Chemotherapy or Radiochemotherapy in Resected Gastric Cancer.

Purpose: Chemotherapy (CT) and radiochemotherapy (RCT) are currently the standard postoperative treatments for resected gastric cancer (GC). However, owing to a lack of predictive biomarkers, their efficacy is currently suboptimal. As tumor microenvironment (TME) has the potential to determine treatment response, we investigated the association of TME status with the efficacy of fluoropyrimidine (FU)-based postoperative CT/RCT in resected GC. Methods: Patients with transcriptome data were screened and selected in three independent cohorts. Favorable (fTME) and poor TME (pTME) were defined by a transcriptome-based TME qualification method. Immune infiltration and hypoxia were assessed. Results: A total of 535 patients were eligible. fTME, indicating the presence of immune activation, was characterized by NK cell rather than CD8+ T cell infiltration. However, postoperative CT/RCT improved overall survival and disease-free survival time more evidently in patients with pTME GC than those with fTME GC. Stratified by stage in fTME GC, stage III patients benefited from postoperative CT/RCT while stage Ib/II patients did not. In comparison, patients with pTME GC benefited from postoperative CT/RCT, regardless of stage. Furthermore, fTME was more hypoxic than pTME, accompanied by a stronger expression of thymidylate synthase (TS)-the target of FU. Stage Ib/II fTME GC was the most hypoxic and had the strongest TS expression across all the subgroups stratified by TME status and stage. Conclusions: We found that fTME, with the enrichment of NK cells, may predict the lack of postoperative CT/RCT efficacy in stage Ib/II GC, which may be associated with hypoxia and TS expression. Further validations and mechanism researches are needed.

The contrary intracellular and extracellular functions of PEDF in HCC development.

Pigment epithelium-derived factor (PEDF), a classic angiogenic inhibitor, has been reported to function as a tumor suppression protein and to downregulate in many types of solid tumors. However, the expression level of PEDF and its role in hepatocellular carcinoma (HCC) are contradictory. The present study investigates the expression and different activities of secreted and intracellular PEDF during HCC development, as well as the underlying mechanism of PEDF on HCC lipid disorders. We found that PEDF had no association with patients' prognosis, although PEDF was highly expressed and inhibited angiogenesis in HCC tumor tissues. The animal experiments indicated that full-length PEDF exhibited equalizing effects on tumor growth activation and tumor angiogenesis inhibition in the late stage of HCC progression. Importantly, the pro-tumor activity was mediated by the intracellular PEDF, which causes accumulation of free fatty acids (FFAs) in vivo and in vitro. Based on the correlation analysis of PEDF and lipid metabolic indexes in human HCC tissues, we demonstrated that the intracellular PEDF led to the accumulation of FFA and eventually promoted HCC cell growth by inhibiting the activation of AMPK via ubiquitin-proteasome-mediated degradation, which causes increased de novo fatty acid synthesis and decreased FFA oxidation. Our findings revealed why elevated PEDF did not improve the patients' prognosis as the offsetting intracellular and extracellular activities. This study will lead to a comprehensive understanding of the diverse role of PEDF in HCC and provide a new selective strategy by supplement of extracellular PEDF and downregulation of intracellular PEDF for the prevention and treatment of liver cancer.

Pigment epithelium-derived factor/vascular endothelial growth factor ratio plays a crucial role in the spontaneous regression of infant hemangioma and in the therapeutic effect of propranolol.

Infantile hemangioma (IH) is a benign tumor that is formed by aberrant angiogenesis and that undergoes spontaneous regression over time. Propranolol, the first-line therapy for IH, inhibits angiogenesis by downregulating activation of the vascular endothelial growth factor (VEGF) pathway, which is hyperactivated in IH. However, this treatment is reportedly ineffective for 10% of tumors, and 19% of patients relapse after propranolol treatment. Both pro-angiogenic and anti-angiogenic factors regulate angiogenesis, and pigment epithelium-derived factor (PEDF) is the most effective endogenous anti-angiogenic factor. PEDF/VEGF ratio controls many angiogenic processes, but its role in IH and the relationship between this ratio and propranolol remain unknown. Results of the present study showed that the PEDF/VEGF ratio increased during the involuting phase of IH compared with the proliferating phase. Similarly, in hemangioma-derived endothelial cells (HemEC), which were isolated with magnetic beads, increasing the PEDF/VEGF ratio inhibited proliferation, migration, and tube formation and promoted apoptosis. Mechanistically, the VEGF receptors (VEGFR1 and VEGFR2) and PEDF receptor (laminin receptor, LR) were highly expressed in both IH tissues and HemEC, and PEDF inhibited HemEC function by binding to LR. Interestingly, we found that propranolol increased the PEDF/VEGF ratio but did so by lowering VEGF expression rather than by upregulating PEDF as expected. Furthermore, the combination of PEDF and propranolol had a more suppressive effect on HemEC. Consequently, our results suggested that the PEDF/VEGF ratio played a pivotal role in the spontaneous regression of IH and that the combination of PEDF and propranolol might be a promising treatment strategy for propranolol-resistant IH.

Kallistatin inhibits lymphangiogenesis and lymphatic metastasis of gastric cancer by downregulating VEGF-C expression and secretion.

BACKGROUND: Tumor-induced lymphangiogenesis and lymphatic metastasis are predominant during the metastasis of many types of cancers. However, the endogenous inhibitors that counterbalance the lymphangiogenesis and lymphatic metastasis of tumors have not been well evaluated. Kallistatin has been recognized as an endogenous angiogenesis inhibitor. METHODS AND RESULTS: Our recent study showed for the first time that the lymphatic vessel density (LVD) was reduced in lung and stomach sections from kallistatin-overexpressing transgenic mice. Kallistatin expresses anti-lymphangiogenic activity by inhibiting the proliferation, migration, and tube formation of human lymphatic endothelial cells (hLECs). Therefore, the present study focuses on the relationships of changes in kallistatin expression with the lymphangiogenesis and lymphatic metastasis of gastric cancer and its underlying mechanisms. Our results revealed that the expression of kallistatin in cancer tissues, metastatic lymph nodes, and plasma of gastric cancer patients was significantly downregulated and that the plasma level of kallistatin was negatively associated with the phase of lymph node metastasis. Furthermore, treatment with kallistatin recombinant protein decreased LVD and lymph node metastases in the implanted gastric xenograft tumors of nude mice. Mechanically, kallistatin suppressed the lymphangiogenesis and lymphatic metastasis by downregulating VEGF-C expression and secretion through the LRP6/IKK/IÒ¡B/NF-Ò¡B signaling pathway in gastric cancer cells. CONCLUSIONS: These findings demonstrated that kallistatin functions as an endogenous lymphangiogenesis inhibitor and has an important part in the lymphatic metastasis of gastric cancer.