<b>Fatty acid analysis</b>

Collect cultured cells(1*10⁷ cells per sample) into centrifuge tubes. After grinding and centrifugation of the cells, the supernatant was taken and vortexed with chloroform, centrifuged, and the lower layer liquid was taken and placed in a sample bottle. It was concentrated and dried, and dissolved in methanol.The cellular metabolites were dissolved in methanol using ultra high performance liquid chromatography ion mobility quadrupole time-of-flight mass spectrometer (Acquity I-class; Waters). Cell samples include PANC-1 and Capan-2 cells upon SCD knockdown or TGM2 knockdown. The experiment was conducted by Instrumental Analysis Center of Shanghai Jiao Tong University. The mobile phase A: Containing 0.1% formic acid water; mobile phase B: Containing 0.1% formic acid acetonitrile (1/1). The gradient was as follows: 95%A and 5%B (initial); 80%A and 20%B (5 min) ; 100%B (18 min); 95%A and 5%B (28 min) with a flow rate of 0.4ml/min in column BEH C18 1.7um，2.1*100mm, column temperature at 45℃. MS conditions were follows: the acquisition mode at MSE; ionization mode at ESI negative, capillary voltage at 2 KV (negative), cone voltage at 40 V, desolvation temperature at 450℃, desolvation gas at 900 L/h, cone gas at 50L/h, source temperature at 115℃, acquisition range at 50 to 1000 m/z, scan rate at 0.2 s, collision energy at 6 eV/20～45 eV; lockmass at 250 pg/μL of leucine enkephalin; flow rate at 10 μL/min; interval at 0.5 s; sample time at 0.5 s; collision energy at 6 eV. Data acquisition and analysis were carried out by Waters UNIFI 1.9.4. A series of FA samples is standard.

将培养的细胞（每个样本含1×10⁷个细胞）收集至离心管中。细胞经研磨、离心后，取上清液与氯仿涡旋混匀，再次离心后取下层液体置于样品瓶中。将该下层液体浓缩干燥后，用甲醇进行复溶。将细胞代谢物用甲醇溶解后，采用超高效液相色谱-离子迁移谱-四极杆飞行时间质谱仪（Acquity I-class；Waters）进行分析。本研究的细胞样本包括经SCD敲低或TGM2敲低的PANC-1与Capan-2细胞。实验由上海交通大学仪器分析中心完成。流动相A为含0.1%甲酸的水溶液；流动相B为含0.1%甲酸的乙腈溶液。洗脱梯度设置如下：初始状态为95%A+5%B；5 min时为80%A+20%B；18 min时为100%B；28 min时恢复为95%A+5%B。色谱柱采用BEH C18（1.7 μm，2.1×100 mm），柱温设为45℃，流速为0.4 mL/min。质谱参数设置如下：采集模式为MSE；电离模式为电喷雾负离子模式，毛细管电压（负模式）为2 kV，锥孔电压为40 V，脱溶剂温度为450℃，脱溶剂气流量为900 L/h，锥孔气流量为50 L/h，离子源温度为115℃，采集质量范围为50~1000 m/z，扫描速率为0.2 s，碰撞能量为6 eV/20~45 eV；锁定质量为250 pg/μL的亮氨酸脑啡肽，进样流量为10 μL/min，间隔时间为0.5 s，采样时间为0.5 s，碰撞能量为6 eV。数据采集与分析采用Waters UNIFI 1.9.4软件完成。本数据集包含一系列脂肪酸标准品。