Journal: Cancer letters

Article Title: DNA-PKcs promotes therapy resistance and metastatic recurrence in neuroblastoma

doi: 10.1016/j.canlet.2026.218383

Figure Lengend Snippet: (A, B) Correlation between PRKDC gene expression levels and NB tumor progression to stage 4. (C) Heatmap of differential expression of DNA replication and repair pathway (KEGG) genes in PTCs (green) at diagnosis and DTCs (red) at relapse. Color intensity represents expression level. Heatmap of KEGG pathways involved in DNA replication and repair in primary tumor cells (PTCs) at diagnosis (green) and in disseminated tumors cells (DTCs) at relapse (red). (D) PRKDC gene expression in PTCs at diagnosis, DTCs at diagnosis and in DTCs at relapse (Ambros study, n=86) revealed a significant upregulation of PRKDC in DTCs at relapse. (E) Western blot analysis in MYCN-amplified (BE(2)-C, LAN-1, IMR-32 and SK-N-DZ) and MYCN-non-amplified (SK-N-AS, SK-N-SH) NB cell lines (*p<0.05, ***p<0.001, ****p<0.0001).

Article Snippet: MYCN -amplified human NB cell lines (BE(2)-C (CVCL_V006), IMR-32 (CVCL_0346), LAN-1 (CVCL_1827) and SK-N-DZ (CVCL_1701)) and MYCN -non-amplified cells (SK-N-AS (CVCL_1700), and SK-N-SH (CVCL_0531)) were purchased from ATCC.

Techniques: Gene Expression, Quantitative Proteomics, Biomarker Discovery, Expressing, Western Blot, Amplification

Journal: Cancer letters

Article Title: DNA-PKcs promotes therapy resistance and metastatic recurrence in neuroblastoma

doi: 10.1016/j.canlet.2026.218383

Figure Lengend Snippet: (A, B) BE(2)-C and SK-N-DZ cells were treated with doxorubicin (A) or etoposide (B), either individually or in combination with peposertib. Clonogenic assay was performed to evaluate long-term cell viability of NB cells. BE(2)-C and SK-N-DZ cells were treated with peposertib (1000 nM), and doxorubicin (BE(2)-C, 75 nM; SK-N-DZ, 10 nM) and etoposide (BE(2)-C, 500 nM; SK-N-DZ, 100 nM). Drugs were removed and replaced with fresh media 48 h later, and colonies were allowed to grow for 14 days. (C, D) DNA damage following doxorubicin (C) or etoposide (D) therapy in combination with peposertib was evaluated in BE(2)C and SK-N-DZ using immunofluorescence staining of γ-H2AX (Ser139) (Red: γ-H2AX; Blue: DAPI; Green: Phalloidin). (E) Clonogenic assay was performed to evaluate long-term viability of NB cells. BE(2)-C NTC and PRKDC knockdown cells were treated with etoposide (500 nM) and doxorubicin (75 nM). Drugs were removed and replaced with fresh media 48 h later, and colonies were allowed to grow for 14 days; *p<0.05, ***p<0.001, ****p<0.0001.

Article Snippet: MYCN -amplified human NB cell lines (BE(2)-C (CVCL_V006), IMR-32 (CVCL_0346), LAN-1 (CVCL_1827) and SK-N-DZ (CVCL_1701)) and MYCN -non-amplified cells (SK-N-AS (CVCL_1700), and SK-N-SH (CVCL_0531)) were purchased from ATCC.

Techniques: Clonogenic Assay, Immunofluorescence, Staining, Knockdown

Journal: Cancer letters

Article Title: DNA-PKcs promotes therapy resistance and metastatic recurrence in neuroblastoma

doi: 10.1016/j.canlet.2026.218383

Figure Lengend Snippet: (A) BE(2)-C GFP-Luc cells were intravenously injected into NOD rag gamma mice. Chemotherapy commenced 6 days post-injection, with q.o.d doxorubicin (2.5 mg/kg, iv) and peposertib (100 mg/kg, gavage) as combination therapy, followed by a single dose of peposertib alone (100 mg/kg) the next day. Bioluminescent imaging (top) and GFP imaging (bottom) to demonstrate therapy outcomes on liver metastasis burden. (B) Bioluminescent signal quantification was used to measure liver metastasis burden at the end of the study (*p<0.05). (C) Gross photograph of GI track in doxorubicin and peposertib combination. (D) Mouse weight.

Article Snippet: MYCN -amplified human NB cell lines (BE(2)-C (CVCL_V006), IMR-32 (CVCL_0346), LAN-1 (CVCL_1827) and SK-N-DZ (CVCL_1701)) and MYCN -non-amplified cells (SK-N-AS (CVCL_1700), and SK-N-SH (CVCL_0531)) were purchased from ATCC.

Techniques: Injection, Imaging

Journal: Cancer letters

Article Title: DNA-PKcs promotes therapy resistance and metastatic recurrence in neuroblastoma

doi: 10.1016/j.canlet.2026.218383

Figure Lengend Snippet: (A) BE(2)-C cells were pre-treated with peposertib for 30 min before IR, then cells were irradiated at 1 Gy and peposertib was removed at different time points (top panel). BE(2)-C cells were irradiated at 1 Gy and peposertib was added at different time points post-IR (bottom panel). (B) Colony viability was measured by colony formation assay. (C) BE2C cells were cultured for 7 days to form colonies before initiating doxorubicin (75 and 150 nM) or IR (1 Gy and 4 Gy) therapy alone or in combination with peposertib. Following treatment, the media was refreshed 48 h later, and the colonies were permitted to grow for an additional 7 days. (D) Colony viability was measured by colony formation assay. (E) Similarly, SK-N-DZ cells were allowed to form colonies for 7 days prior to treatment with doxorubicin (10 or 20 nM) or ionizing radiation (0.5 Gy or 2 Gy), alone or in combination with peposertib. The culture medium was refreshed 48 h post-treatment, and colonies were incubated for an additional 7 days. (F) Represents the Colony viability measurement.; *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001.

Article Snippet: MYCN -amplified human NB cell lines (BE(2)-C (CVCL_V006), IMR-32 (CVCL_0346), LAN-1 (CVCL_1827) and SK-N-DZ (CVCL_1701)) and MYCN -non-amplified cells (SK-N-AS (CVCL_1700), and SK-N-SH (CVCL_0531)) were purchased from ATCC.

Techniques: Irradiation, Colony Assay, Cell Culture, Incubation

Journal: Cancer letters

Article Title: DNA-PKcs promotes therapy resistance and metastatic recurrence in neuroblastoma

doi: 10.1016/j.canlet.2026.218383

Figure Lengend Snippet: (A) Area of irradiation outlined by a light window. (B) BE(2)-C GFP-Luc cells were injected iv into NOD rag gamma mice. Radiation therapy started 6 days after cancer cell injection with daily 2 Gy irradiation alone or in combination with peposertib (gavage; 100 mg/kg) for 4 days. (C) Bioluminescent imaging and (D) GFP imaging demonstrate therapy outcomes on liver metastasis burden. (E) Bioluminescent signal quantification to measure liver metastasis burden at the end of the study (*p < 0.05). (F) Mouse weight. (G) Gross photograph of liver metastasis. (H) H&E imaging of liver metastasis and normal liver adjacent to metastatic tumors. (I ) DNA-PKcs expression in surviving colonies after acute (5 Gy) and chronic (1 Gy × 5 times) IR exposure. (J ) BE(2)-C cells subjected to repeated low-dose irradiation (1 Gy × 5) exhibited increased resistance to acute high-dose radiotherapy (5 Gy) relative to the parental cell line. (K ) PRKDC gene expression in NB tumors with recurrence or progression (Versteeg study, n = 87) revealed a significant upregulation of PRKDC in tumors at relapse. (L) Side-by-side UMAP visualization of NB tumor cell subclusters in post-treatment neuroblastoma at primary (n = 21,248 cells) and metastatic (n = 24,526 cells) sites after re-clustering. Colors represent assigned cell types within NB tumors. The dot plot shows PRKDC gene expression in tumor subpopulations in NB at primary and metastatic locations post-induction treatment. The color scale represents scaled average expression of PRKDC in each tumor type, and the size of the circle indicates the proportion of cells expressing PRKDC . (M) DNA-PKcs inhibition in combination with radiotherapy disrupts self-renewal capacity of BE(2)-C cells. BE(2)-C cells were treated with 5 cycles of doxorubicin (50 nM) therapy or irradiation (1 Gy) alone or in combination with peposertib. (N) Elevated DNA-PKcs expression in metastatic NB cells confers a survival advantage under chemotherapeutic and radiotherapeutic stress. DNA-PKcs inhibition combined with repeated low-dose ionizing radiation impairs cancer cell self-renewal capacity and suppresses tumor relapse.

Article Snippet: MYCN -amplified human NB cell lines (BE(2)-C (CVCL_V006), IMR-32 (CVCL_0346), LAN-1 (CVCL_1827) and SK-N-DZ (CVCL_1701)) and MYCN -non-amplified cells (SK-N-AS (CVCL_1700), and SK-N-SH (CVCL_0531)) were purchased from ATCC.

Techniques: Irradiation, Injection, Imaging, Expressing, Gene Expression, Inhibition